Full Report - Feasibility Study KSCS K-Exim

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ② bevel end joint The bevel end joint is a method used to create sufficient penetration when it is not obtained by the plain end joint. Depending on the diameter and thickness of a pipe, its shape is divided into V-shaped and X-shaped grooves. The figuration of butt-welded joint is shown in <Figure 5.40> and the appropriate weld size is shown in <Table 5.51>. <Table 5.51> Appropriate size of butt welded joint Classification T S D A - I shaped (plain end) ＜4mm 0.5 ~ 1.5mm - 60 ~ 70° 70° V shaped (bevel end) 6 ~ 20mm 0 ~ 3mm ≤ 2.4 mm X shaped (bevel end) ≥16 ~ 20mm 0 ~ 3mm 2mm 2) Lap welded joint <Figure 5.41> Lap welded joint The lap welded joint is a method in which one end of the pipe is formed as bell end, and the bell end is connected to the spigot end in the construction site, and then the inner and outer surface are joined. Also called the bell and spigot joint, it is a method suitable to the large diameter pipe. The figuration of the lap welded joint is shown in <Figure 5.41>. (5) Instructions for welding The welding process is ① to prepare materials for <Figure 5.42> quadric- welding, ② to clean, ③ to do preliminary welding, and ④ section symmetric welding to do regular welding, and the instructions are as follows: process • The large-diameter pipes are joined in the area of bed excavation whereas several small-diameter pipes are welded outside the bed excavation area and then brought down to the excavation area. The maximum allowable displacement of welding spots during the transportation must be less than 2˚. • In the case of the steel pipe with a large diameter, welding is performed after attaching the protective plate of the heat-resisting material to the joints along the circumference of the painting surface inside the steel pipe. This is to 5-82

Chapter 5. Conveyance System Planning prevent weld spatter or slag from coming off to the inside the pipe during welding, which could damage the painting surface. • As shown in <Figure 5.42>, it is advised to use the quadrisection symmetric welding process for a large-diameter pipe. • Weld zones must be free of defects including ① crack, ② insufficient penetration, defective melting, ③ blow hole, ④ slag inclusion, ⑤ under cut, ⑥ overlap, and ⑦ imbalanced weld bead (6) Automatic welding An automatic welding is a welding method in which an automatic molding device maintains or molds the roundness of a steel pipe while an external automatic welding device and internal automatic welding robot connect joints of steel pipes automatically. It can be applied to all welded joint methods including butt welded joint and lap welded joint. The automatic molding device fixes both ends of a steel pipe and automatically adjusts or maintains the pipe’s roundness by using a radial-shaped, hydraulic molding cylinder. Then, the external automatic welding device and internal automatic welding robot carry out the actual welding. Process analysis shows that the automatic welding method has the process period four times shorter than the manual welding method. On the construction and economic front, the automatic method in Korea is estimated to save about 10 percent of the construction costs compared to the manual method, if pipes with a diameter between 700mm and 3,000mm are constructed on the site. This is extremely helpful to enhance workability as it tends to take enormous time to secure the power supply if the construction conditions are poor. In particular, for the construction of large-diameter steel pipes, the automatic welding method will greatly improve the quality of welding. 5.7.3 Excavation, groundwork, and backfilling (1) Pipe installation for regular section A field investigation is conducted on the entire route of the conveyance pipeline, and then the location of the pipe installation is determined by taking into consideration the surveyed matters and local conditions. In determining the depth of cover, both safety and construction cost need to be considered. On the one hand, the bigger the depth of cover, the greater the construction cost. On the other hand, it gets more difficult to secure the stability of the pipeline if the depth of cover decreases. Therefore, the depth of cover should be carefully applied by considering the installation location and current state so that the construction cost is reduced while the stability is ensured. 5-83

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Considering surface load, the minimum cover depth of the pipe is planned to be 120cm and more for the pipe with less than 900mm in diameter. The minimum cover depth is planned to be 150cm for the pipe more than 1,000mm in diameter. <Table 5.52> Criteria for depth of cover classification minimum depth of cover D900mm and less 120cm D1,000mm and more diameter abnormality (provided that, at least150cm) The excavation slope of 1:0.5 is applied in this project, and the sand foundation is planned in order to reduce transverse stress or strain of the pipe. The standard cross-sectional drawing for pipeline installation is shown in <Figure 5.43>. <Figure 5.43> Standard cross-sectional drawing for pipeline installation 5-84

Chapter 5. Conveyance System Planning There will also be pipe protection structures in the terminal end of the pipe, telescopic pipe, a place where displacement restraint is required due to a free end caused by the installation of the block valve, a place with sharp horizontal and vertical bend which continuously uses 22½° bent pipe, and a place where imbalanced pressure is continuously generated by Y- or T- shaped pipe connection. <Figure 5.44> Detail drawing of pipe protection (2) Floatation of steel pipe In the course of installing steel pipes, especially before refilling, when the installation area is flooded due to heavy rain, the steel pipe may float by the buoyancy of the pipe as its inside is empty. The best way of preventing the floatation is to backfill as fast as possible. If the backfilling is failed, it is safe to inject water into the installed pipe. In this case, however, the injection of water which would have a greater impact on the cost and time line when cleaning the inside of the pipe later. On the assumption that the weight per unit volume of soil is 15,6800N/m3, the weight per unit volume of water is 9,802N/m3, and the soil barely contains water, the min. depth of cover to prevent the pipe from floating and dangerous water levels are shown in <Table 5.53>. <Table 5.53> Minimum depth of cover and dangerous water level Conceptual diagram Nominal Thickness Min. cover Dangerous diameter (mm) depth water level H (cm) (mm) H (cm) 500 6.0 44 18 1,000 9.0 97 31 1,500 14.0 144 48 2,000 18.0 195 64 2,400 22.0 231 78 2,600 24.0 250 85 5-85

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.7.4 Pipe installation for crossing section Since this project is in the stage of a feasibility study, we suggest the best possible crossing method based on the examination of the previously surveyed data and a field investigation. In the working design stage, the crossing method will be finalized through a detailed basic study and field investigation on each crossing point. (1) Field investigation of crossing sections A field investigation of roads-, railroads-, and river-crossing routes for this water conveyance pipeline was carried out from March 15th to 21st, 2018. Based upon a conveyance route map plan obtained from the BBWS C3, an extensive field investigation on the entire route was performed. As for the river- and railroad-crossing points at which the crossing points are clearly identified, each and every point was the subject of this field investigation. In contrast, as for the road crossing routes, this field investigation was performed only on major crossing routes because there exist some crossing points that are not clearly identified or subject to change in the future. The latitude and longitude coordinates of each crossing point are shown as in <Table 5.54> and the location map of the field investigation is shown as in <Figure 5.45>. <Table 5.54> Coordinates of crossing points No Classification Crossing point Latitude Longitude 1 Rivercrossing 01 river 6° 24′18.68ʺS 106° 20′47.73ʺE 2 Rivercrossing 02 river 6° 20′39.12ʺS 106° 24′34.85ʺE 3 Railroadcrossing 01 railroad 6° 19′45.36ʺS 106° 25′58.48ʺE 4 Roadcrossing 01 road 6° 20′17.65ʺS 106° 34′28.60ʺE 5 Railroadcrossing 02 railroad 6° 20′13.84ʺS 106° 35′46.81ʺE 6 Roadcrossing 02 road 6° 20′26.44ʺS 106° 38′13.06ʺE 7 Rivercrossing 03 river 6° 19′35.28ʺS 106° 39′33.79ʺE (2) Jacking method for railroad- and road-crossing sections 1) Overview In the case of crossing-sections where it is difficult to install pipes with the open cut method, a trenchless method (Jacking method) is applied by considering traffic hazard, noise, vibration, ground subsidence, and influence of adjacent structure. In selecting a jacking method, the standards and range of the jacking pipe, soil condition of the subject ground, and groundwater level should be considered. The jacking method is an excavation method done either by workers or machines, in which propulsion and arrival access holes are installed in the starting and end points of the propulsion section, and the divided propulsion pipe is pressed by Jack (Jacking machine) into 5-86

Chapter 5. Conveyance System Planning the circle ground. (Compared to other methods such as open cut and temporary facility technique), its features are described as follows: • suitable for road with heavy traffic or railroad crossing sections • when the cover depth is large, constructability and economic feasibility are better than open cut construction • it does not affect traffic flow. and construction generates little noise and vibration • construction cost is higher • construction precision is low <Figure 5.45> Location map of field investigation 2) Jacking method applied section There are two railroad crossing sections which pipelines need to traverse. The Tigaraka Station requires a crossing width of 40m, and the current status is shown in <Figure 5.46>. The crossing point, which is 3km away from Parung Panjang Station heading for Cicayur Station, requires a crossing width of 15m, and the current status is shown in <Figure 5.47>. The Jacking method will be applied to these two railroad-crossing points, and the detailed information about the railroad crossing installation is shown in <Table 5.55>. <Table 5.55> Pipe installation for railroad-crossing sections Classification Measuring point Distance(m) Diameter(mm) Remarks Railroad No.17+135~No.17+195 60 2,000 Actual railroad crossing crossing No.38+693~No.38+728 35 2,000 width: 40m Actual crossing width: 15m 5-87

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.46> Railroad-crossing 1 - Tigaraka Station crossing point Railroad-crossing 1 - Tigaraka Station crossing point Ground plan Picture of current state <Figure 5.47> Railroad crossing 2 - 3km away from Parung Panjang toward Cicayur Station Railroad crossing 2 - 3km away from Parung Panjang toward Cicayur Station Ground plan Picture of current state 5-88

Chapter 5. Conveyance System Planning Among road crossing points in the project area, five points are confirmed through a field study and information obtained from competent authorities. Whether they would be installed by the open cut method or jacking method needs to be reviewed thoroughly when developing a working design. The current state of the road crossing points is shown as in <Table 5.56>. <Table 5.56> Pipe installation for road-crossing sections Classification Measuring point Distance(m) Diameter(mm) Remarks Road No.11+956~No.11+968 12 2,000 Obtained data crossing No.36+132~No.36+143 11 2,000 Field Investigation No.43+574~No.43+585 11 2,000 Field Investigation No.43+900~No.43+908 8 2,000 No.44+235~No.44+245 10 2,000 Obtained data Obtained data The JI. Raya Parung Panjang is a two-lane concrete pavement with the crossing width of 11m, their current state is shown as in <Figure 4.48>. The JI. Raya Cisauk-Legok is a two- lane concrete pavement with the crossing width of 11m, their current state is shown as in <Figure 5.49>. <Figure 5.48> Road crossing 1 - JI. Raya Parung Panjang Road crossing 1 - JI. Raya Parung Panjang Ground plan Picture of current state 5-89

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.49> Road crossing 2 - JI. Raya Cisauk-Legok Road crossing 2 - JI. Raya Cisauk-Legok Ground plan Picture of current state 3) Comparison of Jacking methods The jacking method is divided into a manned technique and a machine technique. The manned technique is generally applied to a propulsion distance less then 100m whereas the machine technique is suitable for soil condition with weathered rock and rock formation. The two techniques are compared as shown in <Table 5.57>. <Table 5.57> Comparison of jacking methods Classification Manned Mechanical Propulsion less than 100m 100m and more distance Soil soil (earth and sand) earth/sand, weathered rock, soft rock, hard condition located at the bottom center of rock Groundwater the propulsion pipe located at the upper center of the level low traffic volume section propulsion pipe Volume of high traffic volume section vehicle traffic 5-90

Chapter 5. Conveyance System Planning The manned technique includes a steel pipe press filling method and GIP method, which are compared as shown in <Table 5.58>. <Table 5.58> Comparison of manned propulsion techniques Classification Press filling method GIP method Overview • A method to press in steel pipes by using • A method to push in pipe by using hydraulic Jack supported by the abutment hydraulic equipment after installing a test wall in the rear side while taking out grouting nozzle for ground reinforcement earth and sand using hand excavation to the leading pipe inside the propulsion pipe. Conceptual diagram Pros • More economical than mechanical • Better ground reinforcement and anti- excavation method leakage than press-in technique Cons • A avoids residual settlement. saves costs Soil • Its short propulsion length is suitable for of disaster prevention, Length a construction site where the mechanical repair/reinforcement technique is not available • Injection of sealing material improves propulsion and anti-leakage, contributing • Working area is small. good for to shorter construction period and better construction in downtown area quality • Impossible to construct in bedrock and • Low constructability in bedrock section, curved section impossible to construct in curved section • Open working face poses high risk of • High risk of deformation and collapse if deformation and collapse if the ground is there is groundwater level or soft ground soft • Earth/sand – weathered rock layer • Earth/sand – weathered rock layer • Less than 100m • Suitable for L= 50~100m The machine technique includes Semi Shield, Shield Jacking, and TPS method, which are compared as shown in <Table 5.59>. 5-91

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.59> Comparison of machine propulsion methods Classification Semi Shield Shield Jacking TPS • A pipe propulsion method • A steel or concrete pipe • A faceplate bit and chamber through excavating and propulsion method using the are installed in front of the ridging using an excavator hydraulic jack in the rear tunneling machine. By with the fore-end closed, the side. The shield machine pumping liquid chemical and semi shield keeps the with the fore-end closed is mud, it stabilizes the water working face stable propelled to excavate and pressure and earth pressure prevent the working face in the upper side. Uses Overview from collapsing. cylinder jack in the rear side and jack pipe installed inside the pipe • Shoe regulating device installed in the front controls the linear alignment and excavation Propulsion head Pros • Stability of propulsion • Semi shield equipment are • Machine excavation secures equipment is higher than that produced domestically, so accuracy and stability Cons of other improvement economically feasible Soil methods in Korea. Suitable • The facility in the rear side • Long-distance excavation is Length for long-distance propulsion. is small in size, suitable for a possible. Shoe regulating small working area. The device controls the linear • Many reference cases sealed propulsion machine is alignment and level stable against groundwater adjustment • Can be applied to a curve or level • a wide range of heads can be long distance • Construction period is applied according to the • Excavates while minimizing shortened stratum of the fore-end the relaxation of the surrounding ground. Can be • Low applicability for a mid • Skilled workers are needed constructed on hard rock to long distance of more than • Takes time to repair 150m • High construction cost, low equipment. The repair work applicability for a short • The minimum diameter is is different depending on the distance of less than 100m D=800mm diameter • Countermeasures are needed • The minimum diameter is if water permeability of the D=800mm ground is high • Takes up a lot of working area. Requires high voltage substation • Soft ground, earth/sand – • Soft ground, earth/sand – • Soft ground, earth/sand – hard rock hard rock hard rock • L=100m and more, suitable • L=50~150m • L=100~400m for medium to long distance 5-92

Chapter 5. Conveyance System Planning 4) Application of the jacking method After comprehensively reviewing the result of the field investigation as well as the opinions from officials at the BBWS C3, it was found that it is difficult to apply the open cut method to the two railroad-crossing sections. So, they need to be installed through the jacking method. As for road-crossing sections, either open cut or jacking method should be decided by taking into consideration the road size and traffic volume. An exhaustive soil investigation should also be carried out in the stage of the working design so that the most proper method can be applied for major propulsion sections based on the soil condition. Jacking method is a pipe installation technique used for tunneling operation while pushing pipe with propulsion force, and it is comprised of the blade, operation, and propulsion parts. Among many jacking methods, double casing and main pipe jacking are the most commonly applied techniques. The former is an inner water pipe propulsion after pushing and installing the external pipe whereas the latter propels the coated ductile cast iron pipe or steel pipe and uses this pipe directly as the water pipe. The most appropriate method must be chosen in terms of constructability and safety through a preliminary study for major jacking sections when developing a working design. Most of all, it is important to bear in mind that soil and ground characteristics are critical indicators in determining constructability or how difficult the construction is. Timely and proper measures need to be taken by surveying various indexes such as N value, ground water level, and strata formation, checking any facilities underground or near the jacking sites, and considering traffic situation as well as construction area. There also need consultations with road and railroad officials before finalizing the jacking method. The conceptual diagram of the propulsion method for railroad-crossing pipe installation is shown in <Figure 5.50>. <Figure 5.50> Conceptual diagram of railroad-crossing propulsion method 5-93

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia The conceptual diagram of the propulsion method for road-crossing pipe installation is shown in <Figure 5.51>. <Figure 5.51> Conceptual diagram of road-crossing propulsion method (3) Pipe installation for river-crossing sections 1) River crossing sections River crossing sections in the project area include the Ciuyah River, the Cidurian River and the Cisadane River. The crossing point of the Ciuyah River has the width of 40m, the slope height of 20m, and the water depth of 0.5m with its bed being the rock ground. The crossing point of the Cidurian River has the width of 20m, the slope height of 10m, and the water depth of 2.5m. The current status of the Ciuyah River crossing point is as shown in <Figure 5.52>. The current state of the Cidurian River crossing point is as shown in <Figure 5.53>. The current state of the Cisadane River crossing point is as shown in <Figure 5.54>. <Table 5.60> shows the list of the river-crossing points where crossing pipe installation is needed. <Table 5.60> river crossing pipe installation Classification Measuring point Length Diameter River (m) (mm) River No.0+543~No.0+583 40 2,000 Ciuyah River crossing No.13+439~No.13+459 20 2,000 Cidurian River No.47+004~No.47+074 70 2,000 Cisadane River 5-94

Chapter 5. Conveyance System Planning <Figure 5.52> River-crossing point - Ciuyah River River-crossing point - Ciuyah River Ground plan Picture of current state <Figure 5.53> River-crossing point - Cidurian River River-crossing point - Cidurian River Ground plan Picture of current state 5-95

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.54> River-crossing point - Cisadane River River-crossing point - Cisadane River Ground plan Picture of current state 2) Comparison of river crossing methods Methods for river-crossing water pipe installation include a bridge-crossing method in which the pipeline goes up across the river, and a bed laying or tunneling method in which the pipeline goes underground crossing the river. The bridge crossing method is divided into a water pipe bridge and additional bridge techniques. Of which, the water pipe bridge technique is classified into a pipe beam system and a reinforced system (pipe beam is reinforced with a truss). The bed laying method is mostly used for pipe installation deep below the ground, and of which, the inverted siphon technique is applied. The tunneling method (inspection path) is adopted when the river is wide or maintenance is required. It is advisable that underwater tunnels secure at least two lines with enough separation distance. In selecting a crossing method, it is important to consider a wide range of factors including constructability, maintenance, and economical feasibility depending on hydraulic properties, flowrate and soil condition of the river; and presence of any existing bridge; and how it will go well with the surrounding environment. In general, the bridge crossing method is favorable in terms of hydraulic properties since it has the shortest path and little flexure. But the expansion joint needs to be installed at one end of the bridge in order to prepare against the differential settlement of the bridge. <Table 5.61> shows the most widely used river-crossing methods – underwater excavation method, water pipe bridge installation method, and press-in propulsion method (Jacking method). 5-96

Chapter 5. Conveyance System Planning <Table 5.61> Comparison of river-crossing methods Classification Underwater excavation Water pipe bridge technique Press-in propulsion crossing crossing technique (Jacking) technique Overview • Excavate the river bed to a • Set up an abutment and • When difficult construction certain depth below the bridge pier in the river, and work is anticipated due to How to equilibrium river bed height, then install the pipeline on the narrow river or many construct and lay the pipeline, then the pier obstructions in the river, the place protective concrete press-in propulsion crossing Pros and • Inspection path needs to be technique is used to cross the cons • Installation of coffer dam installed for a long water bank and the river and cutoff wall pipe bridge • Press-in propulsion from the • Trench excavation and • For a short water pipe protect lowland to the foundation improvement bridge, the pipe itself is opposite protected lowland interpreted as the beam, so • Pipe installation piers are not built in many • Difficult to construct in a • Placement of protective cases large river, construction cost is high concrete • Installation of an abutment • Backfilling and removal of and bridge pier in the river • Good for a narrow river with many obstructions coffer dam • Installation of pipe on the • River bed protection work, abutment and bridge pier • Better to apply to a recently refurbished river where if necessary • Expansion joint and license and permission • Difficult to construct in a provisions against the cold, related civil grievances and if necessary complaints are likely if large river, cost for cutoff excavation is adopted increases, maintenance not • In a large river, its easy construction cost can be • Construction cost is lower than the underwater reasonable for small-medium crossing technique, and river. maintenance is easy maintenance is easy • Difficult to detect a leakage (or an accident) and hard to • In small to medium river, repair construction cost is high • In order to install a structure in the river, permission for • If it is an urban area or has occupation and use needs to heavy traffic, the structure be obtained doesn’t look aesthetically nice • Easy to detect a leakage and repair • In order to install a structure in the river, permission for occupation and use needs to be obtained The underwater excavation crossing technique uses either the open-cut method or temporary facility, and each method is compared in <Table 5.62>. The excavation work is done by occupying the whole surface, so earth and sand are accumulated in the surrounding neighborhood. For this reason, the use of the non-excavation method is increasing in recent years. 5-97

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.62> Comparison of underwater excavation crossing techniques Classification Earth and sand coffer dam Earth and sand coffer dam Earth and sand coffer dam + Open cut + steel sheet + Sheet Pile Conceptual diagram Feature • In the shallow end of the • If the river is deep, coffer • If the river is deep and river, mound earth and dam is not enough to fast flowing, sheet pile is sand above the water line block the inflow of water. used to excavate while and then excavate Then, steel sheet is used installing the support strut to excavate while • Has good constructability blocking water • The support strut reduces for pipeline excavation the constructability for • Has good constructability excavation and pipe • A construction road needs for pipeline excavation installation to be installed • Not as economically • Not economically feasible feasible as the coffer dam (to use Sheet Pile and Constructability method support strut) • Steel sheet plays a role of • Sheet Pile plays a role of cutting off water cutting off water 3) Application of the river-crossing method After comprehensively reviewing the result of the field investigation as well as the opinions from officials at the BBWS C3, it is deemed reasonable to use the underwater excavation crossing method for the planned pipeline. It is worth considering the water pipe bridge method if the conveyance pipeline crosses a large river like the Ciujung river. However, given the size of the rivers in this project, the underwater excavation crossing method is believed to be the best crossing way. <Figure 5.55> Conceptual drawing of the river-crossing method 5-98

Chapter 5. Conveyance System Planning A more comprehensive examination on the river flow quantity and depth needs to be conducted in the stage of the working design to see if other excavation techniques - the coffer dam + open cut technique and the coffer dam + sheet pile technique – can be applied. According to the field investigation in this feasibility, the Ciuiyah river is shallow with a low flow rate and the Cidurian river is narrow with the water depth of 2 to 3m. So, the coffer dam + open cut technique is deemed appropriate for these two rivers. On the other hand, the coffer dam + sheet pile technique is deemed better for the Cisadane river, which is wide and has a high flow rate. <Figure 5.55> shows the conceptual drawing of the river-crossing method. 5.7.5 Road for maintenance and management Ideally it is better to utilize the existing roads to maintain and manage the pipeline. However, if there exists no road or if the pipeline passes through a mountainous region or an agricultural land, it is necessary to install a special road dedicated for the maintenance of the pipeline. The special road needs to have the minimum width which allows patrol cars, vehicles, and equipment enough space to travel for a periodic inspection, maintenance and repair work. Generally, the width of a special road is 4m to 5m considering the width of equipment, but it can be adjusted depending on the geographic conditions if it is unavoidable. Considering that vehicles and equipment may cross each other on the road, the road needs to be widened every 300 to 500m in the straight-line section or at a certain distance if there is poor visibility. If a special road for the pipeline is expected to be used as a general road, it is necessary to ask the relevant government department to open a road. If the water service provider has no choice but to open a road, its alignment, structure, and width, etc. need to be determined through consultation with the said relevant government. The maintenance management road plan is shown in <Table 5.63>. <Table 5.63> Maintenance road plan Planned pipeline Conveyance pipeline Maintenance road Notes Length Diameter Width of land Length Width (km) (mm) acquisition (m) (km) (m) Access road to the 0.42 7.0 booster pumping station 47.93 5.0 Conveyance main line 47.93 D2,000 30 8.56 D600 6 8.56 5.0 Rangkas 4.75 D1,350 13 Bitung 1.2 D350 4 4.75 5.0 - - Small Conveyance Solear 4.8 D600 6 diameter branch line Maja - - short distance Parung Panjang 5-99

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia The maintenance road will be installed with a width of 5m alongside the conveyance pipeline of the first phase, and its conceptual drawing is shown in <Figure 5.56>. <Figure 5.56> Cross-sectional diagram of maintenance road 5.7.6 Connecting the conveyance tunnel and pipeline The intake tower and Ciuyah conveyance tunnel, to be connected to the Karain – Serpong conveyance system, are included in the project scope of the EDCF Karian dam constructor, so they are excluded from the scope of this project. Nonetheless, since the intake tower and the conveyance tunnel are operated under one hydraulic system, they need to be designed and constructed through close consultations. In particular, it is necessary to make clear matters including the scope of the task, how to connect the two facilities, and when to connect them so as to define responsibility and limitation when things go wrong. <Figure 5.57> Connecting the conveyance tunnel and pipeline 5-100

Chapter 5. Conveyance System Planning (1) Scope of the task and limitation It is desired that the constructor of the conveyance tunnel takes charge of the task reaching to the end of the Transition (D4,000mm to D3,200mm) as shown in <Figure 5.57>. Since the connecting parts between the concrete tunnel and the transition pipe require a high precision construction to maintain its capacity to resist pressure and water tightness, there needs a clear-cut definition of responsibility and limitation. Plus, for structural safety of the connecting parts, the contractor may have to put the transition pipe into the tunnel structure and then weld it to the concrete reinforcement. (2) How to join and finish the connecting parts To connect the transition pipe constructed by the tunnel constructor and the Steel pipe D3,200mm installed by the KSCS constructor, the flange finishing method is recommended. This method does not only allow separating the two constructions but also makes it possible to install check valves for maintenance, if necessary. If the two parts are connected by welding, the time of welding must be adjusted and high temperature during welding might damage other construction (3) When to join the connecting parts If the welding is used to join the connecting parts, two constructors need to adjust their schedule and arrange the time of welding. If the flange connection is used, either constructor can join the connecting parts regardless of the construction schedule. Even if the conveyance tunnel constructor begins construction first, the KSCS constructor is able to conduct connection at an appropriate time. 5-101

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.8 Corrosion protection of steel pipe 5.8.1 Anti-corrosion painting (1) Corrosion of steel pipe Steel pipes used for conveyance pipelines have metal properties. That is, they are subject to corrosion, chemical or electrochemical oxidation of metal in soil environment. <Figure 5.58> shows corroded steel pipes. <Figure 5.58> Corroded steel pipe Corrosion of metal is divided into dry corrosion and wet corrosion. Wet corrosion refers to corrosion taking place in the wet environment whether it is in the water or in the ground. Corrosion is also classified into galvanic corrosion and natural corrosion, as described in <Figure 5.59>. <Figure 5.59> Types of corrosion Ordinary soil corrosion Micro cell Special soil corrosion corrosion Natural Bacteria corrosion corrosion Concrete/soil Macro cell Oxygen concentration corrosion (oxygen cell) Corrosion Dissimilar metal Galvanic Leakage current corrosion Interference 5-102

Chapter 5. Conveyance System Planning All metals have their own potential depending on their environment whether they are in the ground or water. Nonuniformity of the material itself (element, stress, and scale) and nonuniformity of the environment (specific resistance, temperature, humidity, oxygen concentration, and ionic weight) cause a partial difference of potential. Such difference gives rise to a number of anodes and cathodes in different parts of a metal. This is when corrosion current flows from the anode to the cathode. Then the ionized metal in the anode is eluted and gradually dissolved into the electrolyte. This electrochemical reaction occurring at the surface of a metal is called corrosion. When the metal emits an electric current, it corrodes. It avoids corrosion by receiving an electric current. The metal being corroded loses electrons and the metal being protected from corrosion receives electrons. (2) Anti-corrosion of steel pipe There are three main conditions for corrosion to occur: ① an electrolyte (soil, seawater, or freshwater), ② potential difference (anode – cathode), ③ wire/cable connecting the anode and cathode. If any one of these three causes is eliminated, the corrosion will stop. <Figure 5.60> shows how a potential difference causes corrosion. <Figure 5.60> Potential difference, a cause of corrosion Anti-corrosion is to protect a metal from being corroded. In a broader sense, it is a way of minimizing the sum of the loss by corrosion and the cost that is required to prevent the installed steel pipe from corrosion during its service life. In other words, anti-corrosion is aimed at inhibiting loss and damage to the steel pipe and at extending the service life. Anti- corrosion methods are shown in <Figure 5.61>. In this feasibility study, the steel pipe’s outer surface which contacts the soil is coated with polyethylene in order to protect the steel pipe against natural corrosion. At the same time, its inner surface which contacts raw water for drinking water is lined with epoxy resin paint. Countermeasures against galvanic corrosion will be discussed in the following. 5-103

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.61> Anti-corrosion method Painting Impressed Current Cathodic Protection Electric Sacrificial anode cathodic anticorrosion protection Anti- Polarized Electric Drainage corrosion Method Forced Drainage Method Insulation Others Plating Corrosion-resistant materials Corrosion inhibitor (3) Methods of coating a steel pipe Once steel pipes for waterworks are buried and begin conveying water, it is not easy to suspend water supply even for a repair. In Korea, a steel pipe is required to have a service life of more than 30 years and the PUSATAB wants it to be more than 50 years. The requirements for painting of a steel pipe are 1) strong adhesiveness to the steel pipe, 2) wear resistance, and 3) hydrophobicity, a physical property of a material that is not attracted to water. The painting materials used for coating the inner surface of a steel pipe that contacts drinking water must not produce any hazardous substances. The painting materials used for coating the outer surface of a steel pipe that contacts soil must not discharge soil contaminants. 1) Coating the inner surface of a steel pipe Methods for the inner surface painting include the Liquid spray using liquid painting materials and the Fusion bonded epoxy coating using powdered painting materials at high temperatures. Widely used coating methods (with liquid epoxy, fusion bonded epoxy, or polyurea) are compared as shown in <Table 5.64>. 5-104

Chapter 5. Conveyance System Planning <Table 5.64> Comparison of inner surface coating methods Classification Fusion bonded epoxy (FBE) Liquid epoxy spray Polyurea - the painting material coated - the painting material is - isocyanate compounds and at high temperature (230°C) composed of the main polyamine components are ingredient – epoxy resin and collisional mixed at high - has a good water resistance, tri-ethylene tetraamine; and temperature (60°C-70°C) and wear resistance, excellent the hardening agent – amine high pressure, and then anti-corrosion property modified and amide sprayed onto the surface of the steel pipe Features - widely applied in oil or gas - mix with a solvent (such as and pipes, which require thinner) and then spray onto - reacts very quickly. the corrosion resistance under the surface of the steel pipe paint film is formed within advantages high temperature and minutes pressure - adhesive to metal, chemical resistant, wear resistant, and - impact resistant, water - the painting material dries oil resistant resistant, chemical resistant, right after application, has wear resistant, and cold good workability - good surface smoothness resistant - the rapid hardening and Disadvantages - widely used in countries in - being mixed with a solvent high-pressure spray of the Europe and the Middle East, (such as thinner, it smells painting material could but there are not many until completely hardened undermine the smoothness or production or application cause disbondment cases for waterworks in - vulnerable to heat, so Korea. dehiscence in the field welded parts may occur Cathodic 5-10mm 8-15mm disbondment 8-15mm - no air bubbles - partially air bubbles Water - hardness decreases less than - hardness decreases more - partially air bubbles resistance 10% than 10% - hardness decreases more (ASTM D than 10% Immediately In 8 hours 870) In 1 hour Hardening time The liquid spray method with liquid painting materials at room temperature has long been used to paint the inner surface of a steel pipe. Painting materials include nanocomposite resin epoxy, ceramic epoxy, or polyurea resin. The fusion bonded epoxy (FBE) coating is one type of the thermoset polymer coating, in which the powdered epoxy remains nonreactive at room temperature but it is melted down to liquid when heated at 180 to 250°C. The liquid epoxy flows into the surface of a steel pipe and fused by thermal and chemical cross-linking. The cross-linking is an irreversible reaction, which makes it impossible to restore the coating to its original form after hardening. Since additional heating cannot melt the coated material, the method is also called a thermohardening coating. 5-105

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 2) Coating the outer surface of a steel pipe One of the outer surface coating methods is the asphalt enamel coating. This method was once used in Korea, but discarded in Korean Industrial Standards and no longer applied due to the following reasons: it has a poor adhesiveness to the steel pipe; it gives rise to cracks or pinholes in cold weather (winter); and it is environmentally hazardous as the painting is melted at high temperatures during summer and contaminates soil. However, this painting material is still being produced and used in Indonesia. <Table 5.65> Comparison of outer surface coating methods Classification PE multi-layered painting F.B.E mono-layered painting Asphalt enamel coating Coating (3-LPE) Thickness 1st layer: F.B.E. FBE (Fusion Bonded Epoxy Asphalt enamel coating Quality 2nd layer: fusion bonded Coating) stability adhesive PE Environmental 3rd layer: fusion bonded PE pollution Used in powder 3.5mm 0.4-0.6mm 3.5mm (1st layer FBE: 0.1mm) 1. high adhesiveness to the 1. high adhesiveness to the 1. low adhesiveness to the steel pipe steel pipe steel pipe : excellent durability : excellent durability : poor durability 2. with high elongation, 2. thermohardening coating: 2. a little shock could cause great shock resistance. No an irreversible coating rub off cracks. 3. method ensures that the 3. cover can be damaged PE(PolyEthylene) is a coating does not melt even during transportation and thermo plastic material that with the additional heat installation has poor heat resistance. 4. cracks or pinholes may take place due to low temperatures (during winter in Korea) 1. No hazardous substances 1. No hazardous substances 1. Coal tar enamel of the dissolve dissolve outer surface of the steel pipe is registered as a hazardous chemical by a Material Safety Data Sheet (MSDS): causes soil contamination Advanced countries U.K., Canada, the Middle Developing countries East If set at 100 (as a reference) 110-120% 50-60% Cost The price of raw material (epoxy) is three times higher than that of PE. The 3-Layer polyethylene coating (3-LPE) is a method widely used in Korea. The 3-LPE is comprised of three layers coated with fusion bonded epoxy, adhesive PE, and fusion bonded powdered PE. The PE coating is divided into fusion bonded coating and extrusion coating. The fusion bonded coating is also called the fluidized bed method in which the powdered 5-106

Chapter 5. Conveyance System Planning material is put in the deposition bed, fluidized with compressed air, and then brought into contact with the heated steel pipe, thereby making the steel pipe coated with the powdered material melted at high temperatures. This method is especially used for small-diameter or deformed pipes. The extrusion coating is a method commonly used for large-diameter steel pipes, in which the pellet-shaped PE is melted in the spiral extrusion machine and extruded in spiral form, thereby making the spinning steel pipe coiled with PE. The mono-layer fusion bonded coating is a method widely used in the United Kingdom, Canada, and Middle Eastern countries. 3) Combination of the inner and outer surface painting There needs a combination of coating procedures and methods used for the inner and outer surface according to heating and cooling temperatures, and the thermal characteristics of painting materials. When coating the outer surface of a steel pipe first, the combination of the 3-LPE for the outer surface and the Liquid epoxy for the inner surface is appropriate. If the inner surface is coated with the FBE after the 3-LPE, that means you have to heat the material at above 200 ℃, which will result in the melting of the coated PE. In contrast, when coating the inner surface of a steel pipe first, the combination of the FBE for the inner surface and the Extrusion painting for the outer surface is suitable. One thing to bear in mind is that it is necessary to ensure a complete seal to prevent the disbondment of the already coated epoxy so that the cooling water does not flow into the surface of a steel pipe. As for the mono-layer FBE, the inner and outer surfaces can be coated simultaneously. Comparison of the combined coating methods is shown as in <Table 5.66>. <Table 5.66> Combination of inner/outer surface coating methods Classification Outer coating first, then inner Inner coating first, then outer Simultaneous coating for coating coating inner and outer surfaces Coating Outer surface: 3-LPE Inner surface: FBE Inner surface: FBE (0.3mm) method Inner surface: liquid epoxy Outer surface: extrusion Outer surface: FBE (0.5mm) coating / 3-LPE Quality - there are many application - FBE is thermoset. Its gel - the FBE for the outer stability cases. With stable process, time is very short (20 – 40 surface is thermoset. but the the coating method is seconds) so it may not react FBE for the inner surface is reliable. with the adhesive PE after its thermo plastic which is gel time. therefore, a precise vulnerable to shock - the service life of the liquid process management is vital. comparted to the outer epoxy is up to 25 years painting material. (relatively short). 5-107

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Given the fact that steel pipes in this project are of high importance and the quality of this project hinges upon their quality, using steel pipes produced and coated with asphalt enamel in Indonesia is not desirable. In this feasibility study, therefore, steel pipes are to be sourced from Korea in order to provide a stable supply of water in the long run and prevent soil contamination. On the specific coating method, it is deemed appropriate that we come up with the most optimal method by thoroughly verify various elements – the coating method locally applicable, the procurement possibility, quality of painting materials, possible damages during transportation, and field painting for welded zones – when developing a working design. 5.8.2 Protection methods against galvanic corrosion (1) Cathodic Protection Painting is a method commonly used to fight corrosion in steel pipes especially in an environment such as water and soil, where there is the electrolyte. Nevertheless, painting itself cannot provide 100 percent protection against corrosion. But both painting and cathodic protection methods are applied together, it is possible to obtain a complete immunity from corrosion. The difference in electric potential between the cathode with high electric potential and the anode with low electric potential is gradually reduced by supplying electrical current (protection current) to the surface of the protected steel pipe, which eventually makes the potential difference zero. This depolarizes corrosion current on a metal surface and stops corrosion, thereby making the protected steel pipe a complete state of anti-corrosion. This technique is called cathodic protection. The first cathodic protection for the pipe installed underground was introduced by Robert. J. Kuhn in New Orleans in 1928. The method used to protect the long-distance underground gas pipeline against corrosion was highly recognized to become the world’s standard. In this feasibility study, the best protection method will be determined in the stage of the working design after a thorough physical inspection on the effect of protection methods, the size of leakage current, any external power supply, and possible inflow of another current. (2) Method for protection against galvanic corrosion 1) Impressed Current Cathodic Protection Corrosion is caused by electrical current released from the metal surface whereas anti- corrosion is caused by electrical current absorbed into the metal surface. The impressed current cathodic protection is a technique used to make electric current flow by connecting an auxiliary electrode (less corrosive metal) to a DC anode and connecting the protected metal to the cathode. The silicone rectifier using an alternating current is often used as a DC power source. As for small power consumption, fuel generator, wind power generator, or solar cells are used as 5-108

Chapter 5. Conveyance System Planning well. If the current required for anti-corrosion changes due to the environmental change or there is a risk of over anti-corrosion, a constant potential device that automatically controls the current for anti-corrosion is used. Graphite, lead alloy, high silicon iron, oxidized steel, and platinum plating titanium are widely used as an auxiliary electrode. This technique is suitable for large leakage current. The conceptual drawing of the impressed current cathodic protection is shown as in <Figure 5.62>. <Figure 5.62> Conceptual drawing of impressed current cathodic protection 2) Sacrificial anode cathodic protection Sacrificial anode cathodic protection is a technique used to prevent a metal from corrosion by electrically connecting a more easily corroded metal which has more negative electrode potential than the maximum negative electrode potential. Here, a more easily corroded metal with lower negative potential is called the sacrificial anode and the protected metal is called the cathode. Since the potential difference causes corrosion of a metal, the sacrificial metal corrodes instead of the protected metal. It is desired that the sacrificial anode has an effective difference in electrode potential against the protected metal during its service life, generate a large quantity of electricity per unit weight, and dissolve evenly. Anode materials commonly used include zinc, magnesium, and aluminum metal, and alloy. The conceptual diagram of the sacrificial anode cathodic protection is shown as in <Figure 5.63>. 5-109

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.63> Conceptual diagram of sacrificial anode cathodic protection Impressed Current Cathodic Protection and Sacrificial Anode Cathodic Protection are compared as shown in <Table 5.67>. <Table 5.67> Comparison of cathodic protection methods Classification Impressed Current Cathodic Sacrificial Anode Cathodic Protection Protection 1. Effective for large-scale structure 1. Effective for small-scale structure 2. Effective for broader area 2. Effective only for small area Effectiveness 3. May affect adjacent facilities 3. A distributed installation of anodes makes current distribution uniform 4. Does not affect adjacent facilities Buildability 1. Can be installed in a narrow space 1. Easy and convenient installation 2. Does not affect other construction 2. May affect other construction work (work can be done processes independently) Economic 1. Small-scale facility: expensive 1. Small-scale facility: inexpensive feasibility 2. Large-scale facility: initial 2. Large-scale facility: with little investment cost is low output current from the anode, a 3. It requires continuous supply of large number of devices need to be power, so maintenance cost occurs installed. Material and labor cost higher than the impressed current cathodic protection 3. In an environment with high specific resistivity, it is not economical. Operation / 1. Can control current with a rectifier 1. No artificial maintenance is maintenance after installation needed 2. Needs maintenance of the rectifier, 2. Cannot control electric current piping, wiring 5-110

Chapter 5. Conveyance System Planning 3) Electric Drainage System Suppose another electric current flows into and travels the underground pipe due to an interference of the subway. When it happens to be discharged somewhere in the pipeline, the entrance is protected against corrosion, but the exit is badly corroded. The Electric Drainage System is an anticorrosion method to send such missing current back to where it needs to go by intentionally forming an electric circuit at the discharging exit. There are Polarized Electric Drainage Method and Forced Drainage Method. ① Polarized Electric Drainage Method If the voltage of the rail is <Figure 5.64> Conceptual map of lower than that of the pipeline, Polarized Electric Drainage Method an electric current will go back to the rail from the surface of the pipe through the soil and causes corrosion. The polarized electric drainage system plays a role of sending back such current to the rail, thereby protecting current from flowing backward. The Polarized Electric Drainage Method can have a good anticorrosion effect with relatively low cost. However, if the pipeline is long, the distance between the installation location of the drainage system and the discharging point will also be great. So, the method is not as effective and needs to be used in combination with other methods. ② Forced Drainage Method The Forced Drainage Method is a combination of the Polarized Electric Drainage Method and Impressed Current Cathodic Protection. It serves two functions: to work as the polarized electric drainage system when the drainage is available and to work as the direct current power supply when the drainage is not available due to the increased voltage of the rail. It is an effective method to prevent corrosion, however, if the system is designed incorrectly, the electric current supplied to the rail may cause a trouble to the railway signal circuit when an external DC power supply is provided, or it may accelerate corrosion. So, extra caution should be paid to when installing the system. The Forced Drainage Method is a great way of preventing the corrosion that cannot be prevented by the Polarized Electric Drainage Method, or corrosion caused by extrusion (where the high ground voltage of the rail is away from the rail.) 5-111

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.9 Quality assurance of pipeline 5.9.1 Hydraulic pressure test Hydraulic pressure tests are used to identify the watertightness and pressure resisting quality of the steel pipe. To check the safety and watertightness of the entire pipeline that is installed, hydraulic pressure tests are to be carried out after construction works including the connection of pipeline, installation of attached equipment, and construction of a concrete barrier are completed. Before injecting water into the pipeline for the hydraulic pressure test, the pipeline needs to be backfilled so that it does not move during the test. In the hydraulic pressure test, it is also important to take time to fill the pipeline with water so as not to destroy the pipeline by a drastic pressurization. Inject water slowly into the <Figure 5.65> Conceptual drawing pipeline and remove the air of hydraulic pressure test inside the pipe. While filling water into the pipeline, keep checking if the air valve works properly to remove air or if the pipeline has any problem. Seek appropriate countermeasures if leakage occurs. It is highly advisable that the hydraulic pressure test is conducted one or two days after the water filling of the pipeline. Test pressure, duration, and allowable pressure drop will be determined by considering various factors including working pressure, pipe type, joint structure, pipeline extension, auxiliary facilities, and construction conditions. The following is how the hydraulic pressure test is carried out. • Before injecting water into the pipe, backfill the pipe for the time being to make sure the pipeline does not move during the hydraulic test. • Pressure meters must be attached to at least two test points of the pipeline, one at the outlet of the pressure device and the other at the highest location of the pipeline. Such pressure meters must be at least five times and at most three times the maximum usable pressure and must be calibrated before use. • An air vent should be installed at the highest point or cavitation point of the tested pipeline, and a drainage valve should be installed at the bottom of the pipe. • When injecting water into the pipe, do it slowly while removing the air inside the pipe. During the filling of water, keep checking if the air valve works properly or if the pipeline has any problem. Seek appropriate countermeasures if leakage occurs. 5-112

Chapter 5. Conveyance System Planning • After filling the tested pipe with water, leave it for more than 24 hours. Remove all the air remaining inside the pipe, then slowly add pressure until it reaches the test hydraulic pressure. (up to 1.5 times the operating pressure) • See if the pressure drop exceeds the allowable level (0.02MPa (0.2kg/cm2)) when the test pressure is maintained for one hour. • The allowable leakage amount varies according to the pipe type, diameter, and joint type. In the case of the socket joint method using a rubber ring, approximately 50~120lit/day is regarded as the reference amount for a 1km long pipe with the diameter of 10mm. • The hydraulic pressure test is performed by dividing the route into sections (with an interval of 200m), it is recommended to test in between block valves. 5.9.2 Nondestructive testing (1) Necessity of non-destructive testing and required number of test objects Nondestructive testing is a wide range of inspecting techniques used to examine a material or article by using physical energy without altering or causing damage to the material or article being inspected. In connection to steel pipe, the nondestructive testing is mainly applied to inspect any defect in welded joints. In this feasibility study, approximately 5 percent of the welded joints in the project area are to be subject to nondestructive testing for the purpose of assuring quality of the welding joints. The estimated number of the test objects is shown as in <Table 5.68>. The total length of weld under the nondestructive test is estimated at 67,977dia-inch. <Table 5.68> Required number of NDT object Conveyance pipeline Steel pipe joint welding NDT Classification Dia. Distance(m) No. of Welding length No. of test Test length (mm) points (Dia-inch) welding points (Dia-inch) phase1 phase2 Phase1 Phase2 phase1 phase2 Phase1 Phase2 Phase1 Phase2 Suction Φ3,200 84 - 14 - 1,792 - 1 - 90 - pipe Φ2,200 100 - 17 - 1,467 - 1 - 73 - Φ2,000 47,925 36,024 7,988 6,004 639,000 480,320 399 300 31,950 20,416 Main line Φ1,800 11,901 - 1,984 142,812 - 99 - 7,141 - - 71 - 1,712 Rangkas - - Bitung Φ600 - 8,560 1,427 - 34,240 10 - 140 branch line - - 40 - 2,058 Maja Φ350 - 1,200 200 - 2,800 branch line - 792 - 41,167 - 40 - 960 Solear Φ1,350 - 4,750 32,113 36,027 branch line - - Parung Φ600 - 4,800 800 - 19,200 Panjang 642,259 720,539 branch line Total 5-113

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia (2) Overview Nondestructive testing includes Radiography (RT), Ultrasonics Test (UT), and Magnetic Particles Test (MT). The NDT is intended for the welded joints of the steel pipe to secure strength against design load and resistance against fatigue failure to a certain extent, depending on the working condition. To obtain information on quality and performance of these welded joints, the condition of the welding and defects are investigated, which should be used as basic data for safety and load carrying capacity assessment of a structure. <Table 5.69> shows NDTs for welded joints, which are widely used in Korea. <Table 5.69> Nondestructive tests for steel pipe welded joints Classification Korea Widely used test Mostly RT. UT only if RT is not available (RT 94%) NDT for Main reason Its reliability is proved over a long time. objectivity is pipe Other tests achieved by film reader Phased array ultrasonic test (PAUT) is used for inspecting heat pipe Relevant law and Radiation safety act regulation Regulation on technical standards for radiation safety and so on Radiation Details Radiation generator (X-ray) is allowed to be used in the safety RT room (an enclosed building made of concrete wall to protect workers as well as ordinary citizens from standards radiation exposure generated by the RT). Beside this dedicated place, only γ-Ray below radioactive isotope Ir- 1920.74 tera becquerel is allowed, so most RTs for welded joints are using γ-Ray. Radiation Worker No more than 400mSv/h per week. 10μmSv/h exposure standards Civilian Access control to an area exceeding 1μmSv/h How to test welded joints Attach a film on the surface of the pipe. place the radiation generator outside the pipe and conduct radiography. it is possible to place the radiation generator inside the pipe if it is inevitable. but in this case, you must obtain permission first. 5-114

Chapter 5. Conveyance System Planning (3) Type of nondestructive testing 1) Radiography (RT) The radiography test is one of the widely used nondestructive testing techniques to detect internal defects by using radiation such as X-ray or γ-ray that penetrates into the object being inspected and forming images on a radiographic film. The biggest advantage of this technique is that it is easy to detect a defect’s features such as size and shape and that the quality of the image obtained for the assessment is so good that the test result can be stored almost permanently. On the downside, it is not easy to get spatial information about the defective area and to calculate the depth of the defect. It is also difficult to detect a two-dimensional defect that has poor directional property. Besides, the radiation generator that emits harmful radiation must be covered by the aluminum cap and stored in a tungsten-shield container to prevent against potential exposure, and its use is strictly limited only to the person with highly specialized skills. In some cases, it may be difficult to use on the construction site due to the bulky radiation generator. It takes a lot of time and money to detect. It is widely used to inspect the inside of the pipe, socket, or some structures whose inside cannot be seen. 2) Ultrasonics (UT) An ultrasound refers to sound waves with a frequency higher than the human ears’ audibility. The ultrasonics test is a nondestructive testing technique to detect discontinuity inside the object being inspected by using ultrasound’s refraction and reflection against the surface with different acoustic impedance, suitable for large-diameter steel pipes. The ultrasonics test has excellent portability and sensitivity and is good at identifying the location and spatial information of a defect. It is safer and more economical than the radiography test. Digital equipment that can computerize data measured on the construction site is available, which makes the testing work more efficient. This technique is used to detect a defect inside or on the surface of the welded joints, castings, rolling, and forgings and to calculate its size and location. It can also measure the thickness of steel member and the rate of corrosion of a pipe. It is mainly used for CO2 welded structures, H beams, and brackets. 3) Magnetic Particle (MT) The magnetic particle test is a nondestructive testing method used to detect a defect on the surface or right under the surface of a ferromagnetic material. When the test object is magnetized, a leakage flux is created in the discontinuity. Then magnetic particles are applied to this area, where particles are concentrated. This technique is portable and economical, and easier to use than the radiography test. It allows a detailed inspection of steel structures with relatively complex figuration. 5-115

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia With the outstanding detection performance, it can detect a microscopic defect and even a small fracture or minor defect on the surface or near the surface, which is invisible to the naked eye. It is widely used on the site for structures, pipes, supports, and piercing welds. Nondestructive testing techniques are compared in <Table 5.70>. <Table 5.70> Comparison of NDTs Technique RT UT MT Principle • It detects defects from • It detects discontinuity • It magnetizes the test the concentration inside the test object by object to create a Test object/ difference between the using the refraction and leakage flux in the application sound and defective reflection phenomena discontinuity, and areas, or change in of an ultrasound magnetic particles, Feature radiation intensity against the surface with applied to this area, are when the penetrating different acoustic concentrated and radiation is irradiated. impedance detected • Inner /outer defect • Inner defect detection • Defect detection for detection for a range of and thickness the surface/ right under materials including measurement for the surface of welded joints, casting materials including ferromagnetic welded joints, casting, substances • Serves as permanent rolling, and forgings record keeping • Applicable to • Applicable to all kinds • Estimates the location ferromagnetic of materials and size of a defect substances • Detects surface / inner • Searches surface/inner • Simple and easy defects defects equipment and method • Requires radiation • Automation • Visual identification of safety management defects • Not applicable to nonmagnetic substances • Rapid and inexpensive (4) Retest criteria for the repaired spots after being rejected A defective area which has failed to pass the inspection will be subject to a retest. Two identical welding spots near the defective area need to be chosen for a retest, and the safety is confirmed only when both spots pass the inspection. Here, identical welding spots mean welding points done either manually or semi-automatically by the same welder, with the same welding position and around the same period. With regard to automatic welding, identical welding points refer to welding points done with the same welding method around the same period. 5-116

Chapter 5. Conveyance System Planning In this feasibility study, five percent of the total welding points are subject to nondestructive testing. If all welding points fail to pass the test, perform rewelding and then conduct a retest for ten percent of the total welding points. If the result of the re-inspection requires repair again or if there is any crack or defective welding, inspect all welded joints with the same welding conditions, repair defects, and conduct a retest. 5.9.3 Commissioning test (water flow test) This conveyance system needs to take raw water from the Karian dam, or a water intake source, and provide a stable supply of raw water to the Serpong and other four water treatment plants. Therefore, it is imperative that we conduct a commissioning test against the entire route of the conveyance system, upon the completion of construction, to see if the system is capable of supplying the required amount of water without leakage or contamination. The following is how the commissioning test is carried out. (1) Before filling the pipeline with water First, clean up the inside of the pipeline throughout the entire route. Next, inspect if there are any particles or substances in joints or the painting is in good condition. Then, double check if any residues remain. (2) When filling the pipeline with water Open block valves, air valves, hydrants, and blow off valves to see if there is any problem. Pay extra attention to the degree of adherence to the air valve’s ball. Make sure all the covers of manholes are closed tightly. Measure oxygen concentration in the valve station before going into the station for field investigation. Enter the station only when there is no problem and have someone stand by outside the station. Test performance of the pump and open the air valve located at the end of the pipeline. Then slightly open the block valve from the pump to start flowing water throughout the pipeline. Keep in mind that you open and close the block valve slowly with extra caution when filling the pipeline with water that water hammer does not take place. Make sure the air inside the pipeline is not eliminated drastically. Never convey water at the maximum capacity of the pump since it increases the risk of an accident. (3) When flowing water throughout the pipeline Once the pipeline is filled with water and reaches the planned pressure, make a tour of the entire route of the pipeline to see if there is leakage or potential risk. Bear in mind for the safety purpose, you determine an appropriate test pressure depending on the pump’s capacity and have someone monitor the operation during the commissioning test. The following are major check items for commissioning test. 5-117

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ① clean up the pipeline using water with residual chlorine concentration. Before flowing water, measure water quality by checking pH, residual chlorine concentration, turbidity, etc. to see if it meets water quality standards. ② start flowing water if the results on water quality show no problems. ③ in order to effectively implement cleansing, the flow velocity must be higher than 1m/sec and the maximum flow velocity during operation time. ④ in case of failure to pass the test, thoroughly identify problematic points and repair. Then conduct a commissioning test again. (4) When inspecting drainage Water supply pipeline is a pressure pipe, which discharges a large amount of water in a moment during the course of cleansing. This could lead to flooding as well as a sudden surge in water level in the sewage system such as outlet channels and rivers. Therefore, examine the sewage system beforehand and let the public know about spillways. It is also important to take countermeasures against discharged water containing chlorine, which is likely to affect the surrounding environment if discharged. 5-118

Chapter 5. Conveyance System Planning 5.10 Building plan of the booster pumping station 5.10.1 Basic direction of building plan (1) Basic direction • All facilities are designed to maintain their functionality and encourage efficient maintenance in the conveyance pipeline system. • A reasonable layout plan is established to support a smooth flow of human traffic for maintenance and for economical design. (2) Functionality • The original functionality of each structure is factored in the layout, floor and section design. • The flow of human traffic for management is clearly established not to cause inconvenience to the maintenance/management function of each structure and facility. • For smoother operation and maintenance, the emergency power unit is placed in the booster pumping station station on the first floor. (3) Economic feasibility • Natural lighting and ventilation are considered to contribute to economical operation and maintenance of a structure. • A structure is designed to realize a pleasant indoor environment and save expenses with reasonable yet economical space arrangement as well as easy maintenance. (4) Safety • The two-way evacuation is designed for disaster prevention and easy evacuation in case of emergency. • Safe traffic line is established for effective maintenance/management and in/out of equipment. • Given a high safety factor of the booster pumping station, it is designed with safe and durable structure. 5.10.2 Layout planning Given the unique characteristics of the booster pumping station, main and auxiliary facilities are placed by considering easy maintenance and economic feasibility while actively seeking ways to make the traffic line effective and to save energy. Things to consider in layout planning are as follows: 1) A building layout plan is determined by considering the operation and maintenance of mechanical and electric equipment for the pumping facility as the most important thing. 2) Related facilities are placed adjacently to shorten the distance for maintenance/operation. 3) Traffic line is designed to make the repair and checkup of equipment most convenient. 4) Harmony with the surrounding environment 5-119

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia • To improve the public perception about a booster pumping facility, the building is designed with a nice clean and friendly atmosphere. Extra caution is paid not to spread noise or vibration coming from the facility to nearby areas. 5) Energy saving building • A plan to adjust sunshine is set up for efficient lighting and heating to make the most use of sunlight. The insulation construction is used for heating and cooling. Energy saving equipment and materials are selected. The booster pumping station needs to secure enough space to install pumps and electric facilities planned for first and second phases. There also need ample space for equipment inspection and maintenance, sufficient story height for equipment and materials, and exit/entry. <Figure 5.66> Building layout plan <Figure 5.67> Building layout plan (2015 PPP report)) 5-120

Chapter 5. Conveyance System Planning <Figure 5.66> shows a new building layout plan, which is devised by taking the aforesaid items into consideration. For reference, the previous building layout plan in the 2014 report on master planning of Karian – Serpong Conveyance System and Water Treatment Plant PPP is shown as in <Figure 5.67>. The site area will be calculated more accurately in the stage of the working design. The estimated site area is compared with that of the 2015 report, as shown in <Table 5.71>. Facilities for the second phase will also be arranged within the overall site area, thus the area for buildings for this plan is more than double the area previously planned. <Table 5.71> Comparison of building area Classification This plan (m2) 2015 report (m2) Building 5,049 2,030 Roads on the premises 1,843 1,998 1,088 2,423 Green area 6,112 6,332 Slope and others 1,074 - 13,857 Parking lot 14,452 Sum 5.10.3 Floor, elevation, and section plan of a building (1) Floor plan • the size of each room is planned by considering mechanical and electric equipment to be installed • rooms are properly arranged according to their intended use and purpose • most convenient traffic line is planned by considering the operation/maintenance of mechanical and electric equipment (2) Elevation plan • the building is designed to express nice, clean, and modern aesthetic beauty to highlight its frontality and symbolism • the building is designed with coherence • the elevation plan is set up by considering how the building can stay in harmony with the surrounding environment 5-121

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia (3) Cross-section plan • The cross-section of each room is designed to make it more convenient for the operator to repair and maintain equipment to be installed. The required cross-section is decided by considering the internal piping and electric equipment based on the ceiling of each room. • An appropriate story height of the pumping station is planned by considering equipment to be installed such as Hoist and Crane. 5.10.4. Finishing plan (1) Interior finishing plan • finishing materials of a building shall be durable, help reduce maintenance costs, and have fire-resistance and chemical resistance according to the intended use and purpose of each room. • energy saving materials are chosen for efficient heating and cooling. • materials that meet the standards and that are highly reliable are used. Those materials difficult to purchase or requiring uncertain construction or special method of construction shall be excluded. (2) Exterior finishing plan • materials for an outer wall shall be durable, coherent, and resistant to minor cracks arising from mechanical vibration. • the exterior wall is built with aluminum sheet panel and soil/earth bricks for convenient maintenance. The hipped roof with the flat slab design is planned so that the building goes well with the surroundings. • with durability taken into account, aluminum windows, stainless steel doors, and aluminum shutters are selected. 5.10.5. Architectural planning An optimal space plan for maintenance is set up with reasonable room layout and zoning plan by considering efficient operation/maintenance and traffic line of users. (1) Building plan of a booster pumping station • the functionality is considered for an efficient operation and maintenance of the pumping station • to make the building go well with the surrounding, aluminum sheet panel + earth/soil bricks are chosen for exterior finishing materials • side windows/doors and clerestory are installed for lighting and ventilation. • traffic lines for maintenance and for equipment entry are separated. • an appropriate height to accommodate the doorway for maintenance is considered. 5-122

Chapter 5. Conveyance System Planning • an appropriate height to accommodate the entry of equipment and materials is considered (crane to be installed) <Table 5.72> Building scheme of booster pumping station 2015 report This plan Site area 14,383 14,383 (m2) 1 basement/3 stories high 1 basement/3 stories high Building size Reinforced concrete structure Reinforced concrete structure Structure 1,419.32 3,418.16 Building area(m2) area(m2) main room area(m2) main room 1B 1,179.90 pump station Floor 1B 5,343.16 pump station area (m2) pump station, pump station, 1F 1,419.32 dynamo-room, 1F 3,418.16 dynamo-room, lobby, warehouse lobby, warehouse MF 342.00 electrical room, electrical room, 839.67 lobby, MF 1,010.32 lobby, upper 2F 342.00 3F upper pump pump station Total station 2F 812.42 operation center, operation center, 106.20 office, office, 3F Total lobby, TM/TC lobby, TM/TC room room water tank room, water tank room, stair hall stair hall 4,122.89 10,690.26 1) Floor plan • the size of each room is planned by considering mechanical and electric equipment to be installed • rooms are properly arranged according to their intended use and purpose • the most convenient traffic line is planned by considering the operation/maintenance of mechanical and electric equipment • an appropriate height to accommodate the entry of equipment and materials is considered (crane to be installed) 5-123

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.68> Floor plan of booster pumping station <1st floor plan> <Mezzanine floor plan> <2nd floor plan> <3rd floor plan> 5-124

Chapter 5. Conveyance System Planning 2) Elevation plan • aluminum sheet and earth/soil bricks are planned for finishing materials in order for the building to be in harmony with the surroundings • windows and doors for lighting and ventilation • an appropriate height that ensures efficient maintenance/operation and easy in/out of equipment is considered. • the building is designed to express modern beauty to highlight new image of the booster pumping station • elevation and mass are formed to stay in harmony with natural scenery and terrain <Figure 5.69> Elevation plan of booster pumping station 3) Cross-section plan • an economically appropriate ceiling height for efficient entry of equipment into the pump station is planned • aluminum clerestories are installed on the outer wall for natural ventilation and lighting • pleasant space is created with natural lighting and ventilation • an appropriate height to accommodate an indoor crane, installed for entry of equipment is planned 5-125

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.70> Cross section plan of booster pumping station (2) Building plan of security office The building plan of the security office is shown in <Table 5.73>. There is no change from the 2014 report on master planning and PPP basic scheme. <Table 5.73> Building plan of security office Building No. of Size Structure Building Floor Main room building area(m2) area(m2) Security 1 1 Reinforced 65.7 49.7 Security office, locker office concrete room, warehouse, lavatory 1) Floor plan • the building is designed to efficiently control the passage of people and vehicles • the building is designed to communicate with interactive systems of the main (administration) building • the glass window facade of the building is planned for easy monitoring and natural lighting. 2) Elevation plan • the building is structured with the vertical mass and hipped roof to highlight its identity as the main entrance • the frontality is secured upon entrance into the site • the split roof design is planned to express aesthetic beauty of the structure. • windows and doors that allow three-sided surveillance are planned 3) Cross-section plan • an appropriate ceiling height and the function of the building are considered • the height of the security space is designed to be horizontal to express a separated mass • a pleasant and open space for guards and visitors • windows and doors for natural lighting and ventilation 5-126

Chapter 5. Conveyance System Planning <Figure 5.71> Floor plan of security office <Figure 5.72> Elevation plan of security office <Figure 5.73> Cross-section plan of security office 5-127

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.10.6 Foundation of pumping station (1) Basic design 1) Basic direction • It is necessary to thoroughly examine site conditions (such as soil condition and the surrounding environment) to select the optimal type of foundation that secures structural stability and economic feasibility. • The soil bearing capacity of the foundation ground needs to be strong enough to support the load of the structure above. The foundation type that prevents the settlement from affecting the structure above is selected. • The foundation type is selected based on the results of indoor and field tests as well as the characteristics of the structure. 2) Criteria for foundation types <Table 5.74> shows things to consider in selecting the foundation type and <Figure 5.74> shows the flow chart. <Table 5.74> Considerations in selecting the foundation type Classification Considerations Ground ∙ Reflect the result of the soil investigation characteristic ∙ Decide whether to use direct or pile foundation depending on the Structure depth of soil layer characteristic ∙ Identify obstruction for excavation works Constructability ∙ Identify current state of soil stratum and load of structure ∙ Consider the height for carrying in equipment and excavation works Stability ∙ Direct vertical bearing capacity and vertical settlement ∙ Stability of excavation during construction Economic ∙ Examine a stable and economical method of foundation construction feasibility ∙ Preliminarily investigate the influence of adjacent facilities and Noise and vibration obstruction ∙ Measure noise and vibration and come up with countermeasures • The foundation type needs to be determined based on the results of the soil investigation, the size of upper load, and other site conditions. The selection criteria are shown in <Table 5.75>. 5-128

Chapter 5. Conveyance System Planning <Figure 5.74> Flow chart of selecting foundation type (2) Selection of foundation type of pumping station 1) Current state of a structure • A structure that needs a foundation review is the booster pumping station, whose specifications are shown in <Table 5.76>. <Table 5.76> Specification of a structure to be examined Basic standards (m) Foundation condition Structure Width(B) Length(L) Depth(H) Soil stratum N value Booster pumping 51.6 117.2 6.3 soft rock - station 2) Selection of foundation type • The result of the soil investigation of the Karian dam conveyance tunnel obtained from the Jakarta office of the Korea Rural Community Corporation showed that TB-12 boring survey is conducted the nearest to the booster pumping station. So, the foundation of the booster pumping station is examined based on the TB-12 boring log as shown in <Figure 5.75>. • According to the TB-12 boring logs, the boring depth is 30m, and the stratum is comprised of earth and sand from the surface to 0.1m deep (beneath the surface) and soft rock from 0.1m to 30m deep. • The ground level of the site is currently EL 50.2~54.0m but is planned at EL 45.67m. • The level of the civil structure will be located 6.2m below the planned ground level. • Accordingly, the foundation will be located 10.7 to 14.5m below the soft rock layer, the direct foundation is deemed possible. • Considering the soil condition of the site and the state of the planned structures, the foundation type is selected as <Table 5.77>. 5-129

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.75> Criteria for s Foundation type Compa Criteria Direct foundation RC PC pile Extremely weak stratum in the middle layer △ ○ ○ × Extremely hard stratum in the middle layer ○ △ ○ × Depth of bearing Gravel stratum in the Gravel diameter less than 5cm ○ × Gravel diameter between 5 - 10cm △ △ stratum middle layer Gravel diameter between 10 -50cm ○ × △ ○ Liquefied ground × △ × Less than 5m × × 5～15m × × Ground Depth of the bearing 15～25m × ○ condition stratum 25～40m ○ ○ ○ × Structure’s State of bearing 40～60m ○ △ feature stratum ○ ○ More than 60m △ ○ Soil of the bearing Cohesive soil (20≦Ν) △ ○ stratum Sand. sand gravel (30≦Ν) × ○ × ○ Large slope (≥30) ○ △ ○ × Surface of bearing stratum has 凹凸 ○ ○ ○ × Groundwater level is close to the ground surface ○ ○ ○ Extremely large water capacity △ State of groundwater × Pressed groundwater of more than 2m from the ground surface Groundwater flow velocity is 2m/min and more Small vertical load (span less than 20m) Normal vertical load (span 20m - 50m) Load size Large vertical load (span more than 50m) Horizontal load is smaller than vertical load Horizontal load is larger than vertical load Depth of less than 5m On water construction Depth of 5m and more Construction Surroundings Countermeasures against vibration, noise ○× condition ○× Influence to adjacent structures ○△ small workspace △ △○ Construction of slope pile Influence of noxious gases Note) Highly suitable ○, Suitable △, Not suitable × 5-13

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