METHOD STATEMENT - Brantas...

ATTACHEMENT LETTER NO: / BAP-WASKITA-WIKA/JMD/IV/2011

METHOD STATEMENT

FOR

OUTLET FACILITIES WORK

CONSTRUCTION OF JATIBARANG MULTIPURPOSE DAM PROJECT

PACKAGE B-1 : DAM BODY AND RELATED STRUCUTRES

BRANTAS ABIPRAYA – WASKITA – WIKA JO.

JATIBARANG MULTIPURPOSE DAM PROJECT

OUTLET FACILITIES 1-1

I. PREPARATORY WORKS

1.1. GENERAL

1.1.1. Structural features (Dimension and Design)

Outlet Facilities is located at the right bank of dam with total length 397m, horse shoe type

section of the internal diameter 2,40m and longitudinal gradient of tunnel is 1/10.

1.1.2. Quantities

The Approximate quantity for Outlet Facilities works is refer to the contract document as

following table :

See Figure 1.1. Outline of Outlet Facilities

1.2. Construction Method

1.2.1. Temporary Access Road to Tunnel Outlet

Alignment temporary access road is started from right side bailey bridge about elevation +

84,0m to control gate station area about elevation + 83,5m. Length temporary Access Road is

about 230m . Type of construction are compacted sand gravel combined with cement soil

t=0,20 m at straight section and Concrete type D at Curve Section. Please refer to figure 1.2.

Temporary Acces Road shall be generally have a driveway width about 6,00 m', where praticable

to do so and not less than 4,00 m. Radius of curvature is not less than 9,00 m. Longitudinal Slope

of the Acces Road not more than 15%. Please refer to figure 1.3.



1.2.2. Temporary Acess Road to Tunnel Inlet

Alignment temporary access road is started from cofferdam about elevation + 113,0m to

inclined intake area about elevation + 123. Length temporary Access Road is about 240m . Type

of construction are compacted sand gravel combined with cement soil t=0,20 m at straight

section and Concrete type D at Curve Section. Please refer to figure 1.4.

Commence construct temporary access road after completion embankment cofferdam.

Embankment temporary access road obtained from result excavation inclined intake dropped

into river.

Temporary Acces Road shall be generally have a driveway width about 6,00 m', where praticable

to do so and not less than 4,00 m. Radius of curvature is not less than 9,00 m. Longitudinal Slope

of the Acces Road not more than 15%. Please refer to figure 1.3.

1.2.3. Temporary coffering at the Outlet

Temporary Coffering is necessary constructed to avoid river water overflow through the

working area to Inlet Tunnel. Concerning to the river wide at Inlet is narrow relatively, there is

difficult to maintain of river to be have width for 15 m', so it is necessary to lowering the river

bed to El.83.5,00 and provide the coffering up to El.89.00. Please refer to figure 1.5.



1.3. Procurement of Equipment and Materials

1.3.1. Equipment

1.3.2. Support

1.3.3. Concrete

No. Description Spesification Obtained From

1 Batching Plant Concrete Class D, 215kgf/cm2 Batching Plant 1

2 Reinforcement bars U30, SII 0136-1984 PT. Hanil Jaya Steel

or JIS G3112 - Surabaya

3 Accelerator (6% cement weight) Technical Spec 9-7 Sika Beton

4 Water Stop Technical Spec 9-38 CV. Beton Teknik

Technical Spec 9-40 - Jakarta



II. OPEN EXCAVATION AND SLOPE PROTECTION

2.1. Excavation At Outlet

According to actual site ground face riverbank at the Outlet area is very steeply sloping /vertical

approximately . Clearing and open excavation at outlet use Hydraulic Excavator. There must

consider to prevent of rupture during excavation for Outlet face. Because of area design

temporary access road actual geology condition which is have slide potentially. Fore pooling

forward method or method by rock bolting shall be provided.

2.2. Protection Works for Slope and Tunnel Mouth (Protection Of Cave In)

Protection for Tunnel Mouth to enforcing the steel portal use Gabion Sand Bag,

The sequent of Open excavation and Slope protection i.e.:

- Clearing/Stripping and excavation by Hydraulic Excavator of Outlet Tunnel mouth

- Rock Bolting dia.22 mm; L = 4,00 m follow of designated the pattern fore pooling.

- Installing H-100 Steel Ribs Support – Outdoor of Tunnel Outlet, 100cm c.t.c = 5set

- Sand bag protection work, surrounding of steel rib support have installed wooden deck

- Wooden deck t =50 mm over outdoor Steel Ribs Support

- Excavating of “outer face” Portion by Giant Breaker.

- Installing H-100 Steel Rib Support – Indoor of Tunnel Outlet, complete with tie bar, steel pipe

& jointing plates will be firmly installed.

- Wiremesh and shotcrete of tunnel t = 10 cm.

Fig. 2.1. Temporay Portal Protection Work for Slope and Tunnel Mouth

FRONT VIEW LONGITUDINAL PROFILE



Fig. 2.2. Pattern Fore Pooling Rock Bolt

2.3. Excavation At Inlet

Excavation at Inlet tunnel will be commence at the same time river closure in near Inlet

Diversion Tunnel. Open excavation for Inclined Intake usually done by combination of

equipment, those are : Excavator and bulldozer . Material excavated at intake structure will be

movement direct to river by dozer. Material excavated using embankment temporary access

road to plan temporary inlet portal.

Fig. 2.3. Plan Excavation at Inlet

Fore Pooling @ 0.5m

D22 L=4.0m (10nos)



Fig. 2.3. Profile Inclined Intake Structures

Excavation at inlet will be execute about elevation + 157m until elevation +123.0m.

Fig 2.4. Excavation El.145.50 Fig. 2.5. Excavation El.138.00

Fig 2.6. Excavation El.130.05 Fig. 2.7. Excavation El.123.00



III. TUNNEL EXCAVATION

3.1. Procedure of Full face excavation

Procedure of excavation will be divided into full face section and bottom section.

Excavation full face section, comply with optimum cutting height is 2.337m (overbreak = 5cm).

Excavation for full face will be commenced for every 1.5 m’ length, continue with supporting works comply sequences as below :

- Steel ribs support

- Wiremesh

- Shotcrete t=10cm

- Rockbolt

- Continue with excavation for next 1.5m’ forward.

Last excavation (bottom portion) will to commence while Installing steel pipe dia. 1400mm and concreting is already for execution

Sequence excavation full face portion started first from downstream outlet tunnel to inlet tunnel within productivity ± 1m/days. Excavation will be started at May 1 2011 and finished March 15 2012 for outlet to inlet tunnel. After river closure, excavation will be commence from 2 direction (Inlet an Outlet).

Productivity = 1m/days (May 2011 – September 2011)

Prudctivity = 2m/days (October 2011 – March 2012)

Length = 370m

Time for completion = 320 days.

1. Productivity from Outlet to Inlet during period May 1 – September 30 2011 = 115m

Remaining excavation after river closure = 255m

2. Productivity 2 direction from inlet and outlet 2m/days begin October 1 2011.

Time for completion = 255/2 = 128days

Estimate finished breakthrough March 15 2012.

Bottom

h = 0.213m

Full Face

h = 2.287m



3.2. Applied Equipment for Excavation and Mucking

3.2.1. Tunnel Excavation

Pick Hammer shall be applied for tunnel excavation with 2 manpower continually each other in

one group workers, excavated material will be loaded to pick up by extend conveyor belt.

Fig. 3-1. Excavation with Pick Hammer by manpower

3.2.2. Mucking

Pick up 4 wheel drive capacity 0.8m3 shall be applied for tunnel mucking in Outlet and lorry

capacity 0,4m3 applied in inlet tunnel.

For effective mucking, the excavated material will be collect in the temporary disposal near of

inlet/outlet portal, and be handled to disposal area by other equipments.

Fig. 3-2. Mucking in Outlet Tunnel

Winches Lorry



Fig. 3-3. Mucking in Inlet Tunnel

3.3. Tunnel Supporting (Shotcrete, Steel Rib Support and Rock bolt)

3.3.1. Shotcrete

- Type Shotcrete for tunnel is dry mix

- Gradation of aggregate shall conform to the specification, cement proportion > 400kg/m3

- Apply machine of pneumatic high velocity for the shotcrete work.

- Application thickness total 10 cm

Fig. 3-4. Sequence Shotcrete in Tunnel

3.3.2. Steel Rib Support

- The support is fabricated from steel H.100.100.6.8, will be installed 1,5m c.t.c.

- Steel Rib Support can be installed ,when steel mesh done install.

- Equipment use for entering and install Steel Ribs Support by 4 wheel drive pick up.

- TheUpper joint of the steel rib will be tightened firmly enough with bolt and nut.

- Steel Rib Support dimension and detail , see figure 3.8 Detail Steel Rib Support.

3.3.3. Setting Wiremesh

- Wiremesh (dia.5 mm, 150 mm x 150 mm) immediately to set after steel ribs have installed,laid between streel ribs and face of excavation.

- Overlap not less than 15cm.

- Wiremesh will be fixed firmly to the steel ribs by wires and rod prevent to displacement due to spraying pressure of shotcrete.

Tie Road Steel

Support

Rod

Wiremesh



3.3.4. Rock Bolt

- Drilling the hole use percussion drill (Legdrill or CRD) dia.38 mm.

- Drill holes must be exactly drilled at the desinated locations and intervals as shown in working drawing.

- Rock bolt material deform bar, fabricated threaded end with nut &washer dia.22 mm,L=1,50m, see figure 3.9 Detail Rock Bolt.

- Fixing bolt/nut by wrench

- Hand grouting to insert of cement plastic into the hole, after rock bolt installed.

3.4. TEMPORARY FACILITIES FOR TUNNEL EXCAVATION (LIGHTING, VENTILATION, DRAIN)

3.4.1. Lighting

Apply halogen lamp 400W near cutting face, as illustrated in longitudinal profile .

3.4.2. Ventilation

Consider to air consumption related to working activity in the tunnel for the workers, equipment

and others with diameter tunnel 2,4m.

Name Total Per unit Total

1 Excavation Full face Pick Up 4WD 1 53.2 53.2 76 Hp/Unit

Incl.mucking Person 8 3 24

2 Shotcrete Dust Cement 1 267 267 400 Kg/m3

3mg/m3 *) Pick Up 4WD 1 53.2 53.2 76 Hp/Unit

Person 6 3 18

Note: *) : Not in the same time with excavation. Total Cosumption = 415.4 m3/min.

No Job ItemConsumer matter Air Consump(m3/Min.)

Remark

Fig.3-5. Sequence Installing Wiremesh and Steel Rib Support



3.4.3. Drain

Draining water from the tunnel to outside by pumping. It necessary to prepare the collecting pit

for pumping location.

Fig. 3.7. Longitudinal Profile Temporary Facilities.

3.4.4. Spoil Bank and Disposal

Spoil Bank or disposal location result from tunnel activity is shown at figure 3.10 , for increase

speed of mucking activity, it necessary to provide the temporary spoilbank of excavated tunnel

material, laid near Outlet/Inlet Portal.

Fig.3-6. Cross Section Temporary Facilities



IV. TUNNEL LINING AND GROUTING

4.1. Procedure

1. Sequence of concrete tunnel lining started from downstream to upstream direction.

2. Concrete lining can be start to commence after completion of steel conduit pipe setting ,

formwork setting and adequate support of steel conduit pipe, request and approval by the

Engineer during inspection.

3. Cleaning use water jet or pressure air compressor.

4. Concrete type D is produced from Batching Plant - wet mix type, and transported to the

location by Agitator Truck.

5. Pouring for concrete lining,conveying of concrete material use portable concrete

pump,without high velocity discharge and resultant segregation. Before completion placing

concrete at the crown, conveying of concrete material with high velocity discharge.

6. Compacting the concrete during laying use pneumatic concrete vibrator dia. 2" and vibrator

plate.

4.2. Setting Steel Conduit Pipe

1. Setting steel conduit pipe after underground excavation completion.

2. Steel conduit pipe transported from motor pool to the location by dump truck 16 ton.

3. Steel conduit can be carry with lorry to inside tunnel, lifting of steel conduit use chain block.

To get elevation which is comply with design, bottom steel conduit will be supported by H-

beam.

4.3. Lining Concrete Placing

1. Concrete type D obtained from batching plant, transported by concrete mixer truck.

2. Placing concrete use portable concrete pump.

3. Compacting concrete use pneumatic concrete vibrator.



LorrySteel Conduit Pipe

Temporary Steel support

Winches

Chain Block

Stefner

H-100x100x6x8

100x100x8

Fig.4.1. Setting Steel Conduit Pipe

Fig.4.2. Placing Lining Concrete

Concrete Pump

Mixer Truck

Concrete Steel Pipe

Temporary Steel support

H-100x100x6x8

100x100x8

Stefner

Steel Conduit Pipe

Concrete Type D



4.4. Consolidation Grouting and Curtain Grouting

- Steel casing pipe dia. 50 mm shall be embed to the concrete lining where conformed with

the points position for drilling and grouting.

- Commencing of Consolidation Grouting and Curtain Grouting after shotcrete lining have

minimum 28 days age.

- Rotary Drilling will apply for drilling work.

- Quantity of Curtain grouting L= 180m, Consolidation grouting L=240m.

- Equipment and related drilling and grouting activities can illustrated in Figure 4.3.

Fig.4.3. Equipment Drilling And Grouting

Fig.4.4. Profile Arrangement Grouting Outlet Facilities



Fig.4.6. Typical Arrangement Curtain Grouting

Fig.4.5. Typical Arrangement Consolidation Grouting



V. CYCLE TIME ESTIMATION

5.1. Time Schedule for Outlet Facilities Construction Works

5.1.1. Open Excavation

Open excavation for temporary portal and inclined intake sturcutres will be done by combination

of equipment, those are : Excavator, Buldozer for excavating/loading and Dumptruck for hauling.

The expected hourly production is about 40 m3 , with normal dayworks ( 8 hr /day) the

production will be 320 m3/day.

The cycle time is calculated based on the production of major equipment (excavator): 40 m3/hr ~

320 m3/day . Production for 1 month will be = 8,000 m3. Cycle time open excavation using for

excavation temporary access road and excavation in inlclined intake structures.

5.1.2. Underground Excavation

Excavation for outlet facilities using full face cut method with 2 shift working per days.

Underground excavation will be done by pick hammer.

5.1.3. Lining Concrete

Lining concrete for outlet facilities will be designed for 6 metre , except for curve section it will

apply 3 metre. Basically steel conduit pipe dia.1400mm will be installed earlier. Cycle time for

lining work is 6m / 3days.

5.1.4. Consolidation /curtain grouting

*) Please see detail time schedule.



VI. QUALITY CONTROL

6.1. Survey Works

Prior to commencement of excavation, temporary bench mark and reference point to be set up at

each portal area of tunnel. The points shall be places where no damage or movement are expect

and well protect. During tunnel excavation line and level marked by painted nail on the shotcrete

surface, will be setting up as near from the cutting face, that could be based of works.

During underground excavation must be checked to existence of displacement geology condition

using ekstensometer. Method of data sampling for displacement is executed once weeks.

6.2. Laboratory and Testing

No Work Activity Type of Test RemarkWater Pressure Test - 1 Stage = 5m’, 5 pressure/5minutes

Washing andTesting - Test Pressure

Material Test - Water shall comply Clause 9.7.

- Aggregates shall comply Clause 9.5.

Trial Test - Field trials,horizontal&Vertical,comply

to ASTM C 42.

Sampling Test - Compressive strength test comply to ASTM

C.42. - Sample test 1 core per 3 span.

Pull Out - 80 of cracking load.

- Sample test 1 per 25 Installed Rockbolt

Material - Cement, by factory

- Aggregate shal comply to Clause 9.5.3,

and Clause 9.5.4.

Concrete test - Shall comply to Clause 9.14.

3 Rockbolt

Concrete4

1 Drilling and Grouting

2 Shotcrete



6.3. Mix Design Trial Mix Shotcrete

6.4. Mix Design Trial Mix Concrete Type D

Site Mixing Adjustment Rasio S/A : 53 %

Vol = 1.000 m3

m3

Vol = 1.00 m3 8.530

Water = 142.824 Kg 0.176

Cement = 320.000 Kg 8.705

Fine Agg. = 1050.356 Kg

Coarse Agg. = 882.990 Kg

Add.-Sika = 1.600 ltr

1.600Site Mixing Volume = 1.000 142.82 320.00 1050.36 882.99

Site Mix Water Content(%)

Mixing Adjustment 142.82 320.00 1050.36 882.99 1.600

7.500 2.640

Absortion (%)

2.987 2.547

(Kg) (ltr)

215 20 11 ± 2 1.5 59 53 189 320.00 1005.00 882.17 1.600

Kg / Cm2 (mm) (cm) (%) (%) (%) (Kg) (Kg) (Kg)

Unit Weight (kg/m3)

Water Cement Fine Agg.Coarse

Agg.

Add.-Sika

Basic Maximum

size of

Coarse

Aggregates

Range of Slump

Range of

Air

Content

W/C

RatioS/A Ratio

Type. D0.5 %x C

Name

Date

Prepared and Tested byContractor

Sign

Name

Date

Witnessed and Checked byConsultant

Sign

Name

Date

Approved byEngineer's Representative

Sign



6.5. Pull Out Test

Testing pull out will be taken when the shotcrete age reach 1 (one) day, hollow jack equipment

shall be use.

DIRECTION OF PULL OUT

ESTIMATED BREAKING LINE

SHOTCRETE

SHOTCRETE

HOLLOW.JACK

PRESSURE GAUGE

SUPPORT RING

The Formula of pull out test can be shown as follow :

τ = P / A

A = π ( D / 2 + W / 2 )√ H2 + ( D / 2 W / 2 )2

where :

τ = Pull out pressure

P = Maximum Pull Out Force ( N )

A = Surface area of cone shape of shotcrete pulled out

D = Upper diameter of Cone shape ( mm )

W = Lower diameter of Cone shape ( mm )

H = Hieght of Cone shape ( mm ) Conversion into compressive strength will be 4 times of pull out test

- Sampling for σ3,σ7 and σ28 obtained by coring from test panel box, and will be tested by

compression strength.



Fig : Rock bolt Installation

1. anchor plate

2. hex nut

3. threadbar

4. Grouting by Cement milk + add sika Intraplas- Z

fIg : Rock bolt Pull out test



FLOW CHART ROCK BOLT PULL OUT TEST

NB :

1. Drilling Hole deep 1.5m , equipment leg drill

2. Cleaning out hole by air compressor

3. Grout the hole by cement grout ( cement is inserted in a plastic medium and inserted in the hole )

4. Then inserted after the cement rock bolts inserted into holes had been driven by

5. close the gap between the rock bolt holes so that no spills cement with cement paper.

Rectify

No

Rectify

No

The fig : The squence of work for leveling concrete and backfill concrete of Spillway and Outlet, Gallery work

Construction Method / ProcedureConcrete Work

Start

Request Joint Inspection to Check Foundation

Claening off of foundation

Satisfactory ?

Form Work Final Cleaning

Request Joint Inspection before Placing Concrete

Satisfactory ?

Palcing Concrete Joint treatment Removal of forms Curing

End

Reinforcing bar Arrangement

Check Reinforcing bar Arrangement Check instalation form work

1.Outline of the Work

(1) Structural Features (Dimension and Design)

(2) Quantities

Quantity for Diversion Tunnel works is refer to the Contract Document as Follow :

D. Tunneling

D.1 Underground Excavation

D.1.1 TS.4.1.9.b for Diversion Tunnel m3 18.300

- Upper Half m3 10.500

- Lower Half m3 7.800

D.2 Furnishing & Installing Steel Rib Support and Accesories

D.2.1 TS.7.7.7 for Diversion Tunnel tonne 200

D.3 Production and Placing Shotcrete Lining

D.3.1 TS.7.2.15 for Diversion Tunnel m2 1.800

D.4 Furnishing & Installing Steel Mesh Reinforcement

D.4.1 TS7.5.4 for Diversion Tunnel kg 11.400

D.5 Furnishing & Installing Rock Bolts

D.5.1 TS.7.3.7 for Diversion Tunnel ( 25 mm dia. ) m 17.400

I.9 TS9.30.3 Concrete Type A for Diversion Tunnel Lining. m3 6.800

See Figure-1 : Outline of Diversion Tunnel

2. Construction Method

2.1. Preparatory Work

2.1.1 Acces Road to Tunnel Outlet

(1) Alignment of Acces Road to Tunnel Outlet

(2) Design of Acces Road (Slope, Section and Curvature)

Longitudinal Slope of the Acces Road not more than 15%. Please refer to Figure-2b.

(3) River Crossing Facilities

Method Statement for Diversion Tunnel Works

Description Unit TotalItem No.Payment

Clause

Diversion Tunnel is located at the left bank of the damsite with total length of about 441m, horse shoe

type section of the internal diameter of 5,60 m and longitudinal gradient of the tunnel is 1/30.

Acces Road to Outlet Div. Tunnel is started from Point A about elevation +180,00 m' , and finally to Point

B about elevation +85,00 m'; length of Acces Road is about 815.80 m'. Type of construction are

Compacted Sand Gravel combined with Cement Soil t=0.20 m at straight section and Concrete Type D at

curve section. Please refer to figure-2a

Temporary Acces Road shall be generally have a driveway width about 6,00 m', where praticable to do

so and not less than 4,00 m. Radius of curvature is not less than 9,00 m.

The River around the Outlet Tunnel is about 15-20 m' wide. It is necessary to build bridge construction

crossing the river from right to left side . Bailey Bridge is reasonable to install crossing the river through

to the Outlet Tunnel location. It is designed having length about 24 metre at elevation +83.00 .

At the beginning, the abutment of bridge will be built with Concrete Type D both at right and left section.

The temporary bamboo bridge will be installed to deliver labours and also concrete material crossing the

river. Next the bailey bridge component will be assembled at land side and will be Installed using

cantilever method. Please refer to Figure-3 .

(4) Temporary Coffering at the Outlet

2.1.2 Acces Road to Tunnel Inlet

(1) Alignment of Acces Road to Tunnel Inlet

(2) Design of Acces Road (Slope, Section and Curvature)

Longitudinal Slope of the Acces Road not more than 15%. Please refer to Figure-2b.

(3) Coffering

Temporary Coffering is necessary constructed to avoid river water overflow through the

working area to Inlet Tunnel. Concerning to the river wide at Inlet is narrow relatively, there

is difficult to maintain of river to be have width for 15 m', so it is necessary to lowering the river

bed to El.98,00 and provide the coffering up to El.105.00

For Detail see Figure 3b.

Temporary Coffering is necessary constructed to avoid river water overflow through the working area

of Outlet Tunnel. The river condition at outlet should be maintained to keep the width of river not less

than 15 metre . Coffering elevation at outlet is designed up to El.86.00 , Please refer to Figure 3a.

Acces Road to Inlet Div. Tunnel is started from Point C about elevation +132,00 m' , and finally to Point D

about elevation +101,77 m'; length of Acces Road is about 1,379 m'. Type of construction are Compacted

Sand Gravel combined with Cement Soil t=0.2 cm at straight section and Concrete Type D at curve

section. Please refer to figure-2a

Temporary Acces Road shall be generally have a driveway width about 6,00 m', where praticable to do

so and not less than 4,00 m. Radius of curvature is not less than 9,00 m.

Inlet Structure will be commenced at the 1st dry season as the priority before excavation of inlet tunnel

begin. The construction of Inlet structure doesn't have enough space for equipment operation, so it is

difficult to construct both structure and tunnel in the same time.

2.1.3 Procurement of Equipment and Materials

(1) Equipment (Common use Equipment, Load Header, Centre, etc.)

No Total Unit Note

- Excavating :

1 Road Header 1 Rental

2 Pick Hammer 2 Owned

3 Excavator+Breaker 1 Rental

- Hauling :

4 Wheel Loader 1 Rental

5 Dump Truck 3 Owned

- Supporting works :

6 Welding Trafo 2 Owned

7 Bar Bender 1 Owned

8 Bar Cutter 1 Owned

9 Shotcrete Machine 2 Owned

10 Crawler Drill Rig (CRD) 2 Owned

11 Legdrill 2 Owned

12 Grout mixer 2 Owned

13 Grouting pump 2 Owned

- Concrete Lining

14 Agitator Truck 3 Owned

15 Concrete Pump 1 Owned

16 Concrete Vibrator 4 Owned

17 Centre/Sliding Form 2 Owned

18 Crane Truck 1 Rental

- Other's Equipment :

19 Air compressor 2 Owned

20 Blower / Ventilator 2 Owned

21 Submersible Pump 2" 2 Owned

22 Generator Set 1 Owned

23 Hand Grouting 1 Owned

(2) Support (Rock Bolt and Stell Rib, etc.)

No Total Unit Note

1 Rock Bolt L = 4,00 m' 15.400 m' SD-35;JIS G 3112

2 Rock Bolt L = 3,00 m' 2.000 m' "

3 Steel Mesh 11.400 Kg ASTM A 185

4 Steel Rib Support 200 Ton JIS G 3103, SS 400

(3) Concrete ( Cement, Aggregate, Water, Reinforcement Bars, Form etc.)

No Type/Specification Obtained From

1 Batched Plan Concrete Class A, 270 kgf/cm2 PT. Armada Hada (Readymix) Graha - Semarang

2 Reinforcement Bars U30, SII 0136-1984 PT. Hanil Jaya Steel

or JIS G3112 - Surabaya3 Accelerator (6% cement weight) Technical Spec 9-7 Sika Beton4 Water Stop Technical Spec 9-38 CV. Beton Teknik

Technical Spec 9-40 - Jakarta

Description

Description Specification

Type/Specification

90 kW

8 PS

38 mm

200 x 2 liter

97/200 ltr .min

2.2 m3, Side Dump

0.8 m3

4 m3

300 A

3 PS , D32"

10 m3/hr

62 mm

3 PS , D32"

37 KVA

H > 15 m'

250 KVA

-

D25, Deform Bar

Ø5-150x150 Wire St.Fab.

H-125x125x6.5x8

"

Description

5 m3

40 m3/Hour

Dia. 2"

R = 2.800;L=6.000

5 Ton

17 M3/Min

2.2 Open Excavation and Slope Protection

(1) Excavation at Outlet

According to actual site ground face riverbank at the Outlet area is very steeply sloping /vertical

approximately . Clearing and open excavation at outlet use Hydrauic Excavator

There must consider to prevent of rupture during excavation for Outlet face.Fore pooling method forward or method by rock bolting shall be provided.

(2) Protection Works for Slope and Tunnel Mouth (Protection of Cave In)Protection for Tunnel Mouth to enforcing the steel portal use Gabion Sand Bag,and necessaryto shotcrete the rock face arround of outlet.

See Figure 4a : Conceptual Protection Work for Slope and Tunnel Mouth.

The sequent of Open excavation and Slope protection i.e.: - Clearing/Stripping and excavation by Hydraulic Excavator of Outlet Tunnel mouth - Rock Bolting dia.25 mm; L = 4,00 m follow of designated the pattern - Installing Anchor D 16 L=1,2 m ;45 nos - Excavating of Portal Foundation by Excavator - Setting position of Portal, 3m length from outer rockwall toward tunnel axis - Backfill concrete for Portal Foundation - Setting Re-Bar and formwork for 1st stage - Placing Concrete 1st stage h=2,4 m - Setting Re-Bar and formwork for 2nd stage - Placing Concrete 2nd stage h=2,4 m - Setting Re-Bar and formwork for 3rd stage - Placing Concrete 3rd stage h=2,297 m

- Setting Re-Bar and formwork for 4th stage

- Placing Concrete 4th stage h=2,253 m

See Figure 4b : Placing Concrete for outlet portal

2.3 Tunnel Excavation

(1) Procedure of Short Bench Cut

Procedure of excavation will be divided into upperhalf section and lowerhalf section.

- Upper half section, comply with optimum cutting height of Road Header is about 4,00 m mea-

sured from track shoe to upper roof of tunnel excavation.

- Excavation for upper half section will be commenced for every 1.5 m' length, continue with

supporting works with the sequences as below :

- Primary Shotcrete t = 5 cm, an waiting for 2 hours

- Wiremesh

- Steel Rib Support upper portion

- Rockbolt

- Secondary Shotcrete t = 10 cm.

- Continue with the excavation for next 1.5 m' forward

- After completion of upper half for 30 m', then the lowerhalf section excavation can be executed.

- Height of bench is 2,235 m to the bottom of lowerhalf excavation.

- The excavation of lowerhalf section will be executed for 3.00 m' forward continue with

the supporting work, with the sequence as below :

- Primary Shotcrete t = 5 cm

- Wiremesh

- Steel Support lower portion

- Rockbolt Note :Last Excavation(Bottom Portion) will to commence while invert

- Secondary Shotcrete t = 10 cm. portion of concreting is already for execution

- Continue with the excavation for next 3.00 m' forward

(2) Applied Equipment for Excavation and Mucking

i. Tunnel excavation.

Road Header shall be applied for tunnel excavation, electromotor power belt conveyor extension

is necessary involved for extend to convey the excavated rock and directly fill to the dump truck.

Lower half portion excavation can be carry on alternative by Giant Braker Excavator, excavated

material will be load to Dump Truck by Wheel Loader.

ii. Mucking

- Dump Truck Cap.4m3 shall be applied for tunnel mucking.

- Procedure for applied equipment for excavation and mucking is illustrated in Figure 5.

- For effective mucking, the excavated material will be collect in the temporary disposal near of

Inlet/Outlet Portal, and will be handled to disposal area by other equipments.

(3) Tunnel Supporting (rock Bolt, Shotctrete and Steel Rib Support)

i. Rock Bolt

- Drilling the hole use percussion drill (Legdrill or CRD) dia.40 mm.

- Drill holes must be exactly drilled at the desinated locations and intervals.

- Rock bolt material deform bar,fabricated threaded end with nut &washer dia.25 mm,L=3,00m.

and L = 4,00 m for type "a" support.

- Chemical anchor - epoxy resin shall be applied.

- Fixing bolt/nut by wrench

- Hand grouting to insert of cement plastic into the hole, after rock bolt installed.

See Figure 6.

Lower half = 2,235 m

0,645 m

Upper Half = 4,,00 m

ii.Shotcrete

- Type Shotcrete for the tunnel is wet mix.

- Gradation of aggregate shall conform to the spacification, cement proportion >400 Kg/m3

- Apply machine of pneumatic high velocity for the shotcrete work.

- Application thickness total 15 cm

For illustration see Figure 7

Figure 7

iii.Steel Rib Support

- The supprort is fabricated from Steel H.125.125.6,5.9, will be installed 1,00m c.t.c.

- Steel Rib Support at upperhalf section portion can be installed ,when primary shotcrete finish

and setting time about 2 hours later.

- Equipment use for entering and install Steel Rib Support, Hydraulic Excavator and Dump Truck.

- TheUpper joint of the steel rib will be tightened firmly enough with bolt and nut.

- The base plate of the upper Steel Rib Support will be laid on the correct position.

- Steel Rib Support of Lower Position will be installed after the lower half excavation and the

primary shotcrete finish, and connect by firmly bolting with the upperhalf Steel Rib Support.

Steel Rib Support dimension and detail, see Figure 8

iv.Setting Wiremesh

- Wiremesh (dia.5 mm, 150 mm x 150 mm) immediately to set after steel ribs have installed,laid

between steel ribs and face of primary shotcrete t = 5 cm.

- Overlap not less than 15 cm.

- Wiremesh will be fixed firmly to the steel ribs by wires prevent to displacement due to spraying

pressure of shotcrete.

(4) Temporary Facilities for Tunnel Excavaion (Lighting, Ventilation, Drain)

i.Lighting

Apply Flourescent lamp and Haloge lamp and movable Halogen lamp near the cutting face , as

illustrated in Figure 9.

Figure 9 : Lighting in Tunnel

WATER

TANK

SHOTCRETE MACHINE AIR COMPRESSOR

WATER PUMP

TRUCK MIXER

FLOURESCENT

LAMP 25W

LONG VIEW, LAY OUT OF LIGHTING

FLOURESCENT LAMP 25W @ 8m' LAMP 400W @ 15 M'

CUTTING FACE

FRONT VIEW

ii.Ventilation

Consider to air consumption related to working activity inthe tunnel for the workers,equip-

ments and others can be estimated as follow :

Name Total Per unit Total

1 Excavation Upperhalf Road Hd 1 0 0

Incl.mucking D.Truck 4T 2 54 108 90 Hp/Unit

Person 6 3 18

2 Excavation Lowerhalf Excav. 1 110 110 110 Hp/Unit

Incl.mucking D.Truck 4T 2 54 108 90 Hp/Unit

W.Loader 1 110 110 110 Hp/Unit

Person 6 3 18

3 Shotcrete Dust Cement 0 267 0 400 Kg/m3

3mg/m3 *) D.Truck 4T 0 66 0 110 Hp/Unit

Person 0 3 0

Note: *) : Not in the same time with excavation. Total Cosumption = 472 m3/min.

Fan use =1 x 37 KVA

iii. Drain

Draining water water from the tunnel to outside by pumping with electric water pump or

submersible pump. It necessary to prepare the collecting pit for pumping location.

(5) Spoil Bank and Disposal

Spoil Bank or Disposal location result from Tunneling activity is shown at Figure 2, for increase

speed of mucking activity, it necessary to provide the temporary spoilbank of excavated tunnel

material, laid near Outlet/Inlet Portal.

(6) Safety and Health Management for Underground Works

Will be submitted later at separate proposal.

No RemarkConsumer matter Air Consump(m3/Min.)

Job Item

Sump Pit &

Temporary Ditch in Tunnel

Pumping and Dispose to River

Hose/Steel Pipe

Submersible

Pump 2"

2.4 Tunnel Lining and grouting

(1) Procedure

- Sequence of concrete tunnel lining started from the downstream to upstream direction.

- Cleaning use water jet or pressure air compressor.

- Concrete type A is produced from Batching Plant - wet mix type, and transported to the location

by Agitator Truck.

- Pouring for concrete lining,conveying of concrete material use portable concrete pump,without

high velocity discharge and resultant segregation.

- Concrete shall be forced into the top of placement to fill completely the crown at the tunnel, the

discharge pipe shall be burried at least 2 m.

- Compacting the concrete during laying use pneumatic concrete vibrator dia. 2".

- Remove the Crown Form minimum of 3 days age.

(2) Form Works/Reinforcement Arrangement

- Use Fabricated Sliding form, 12m long setting@6m length per segment, see Figure 10

- Reinforcement arrangement will be submitted later on.

(3) Lining Concrete Placing

- Concrete Type A obtained from Bathing Plant, transported by Mobile Concrete Mixer.

- Placing of concrete use Portable Concrete Pump.

- Compacting concret use pneumatic concrete vibrator

Concrete placing for Lining is illustrade at Figure 11.

Concrete Lining Upper/Crown Portion

Concrete Lining Invert

Figure 11

- Concrete lining can be start to commence after completion of rebar setting , formwork setting and

adequate support of formwork , request and approval by the Engineer during inspection.

CONCRETE

PUMP

CONCRETE

MIXER MOBILE

12,00

CONCRETE STEEL PIPE STEEL SLIDING FORM

CONCRETE

PUMP

CONCRETE

MIXER MOBILE

12,000

CONCRETE STEEL PIPE

(4) Back Fill Grouting

Backfill grouting execution :

- Equipment to be used :

2 units grouting pump & 2 units grouting mixer stayed on truck for grouting operation

- Two stage of grouting :

> Stage 1 : grouting with proportion of 2 water : 1 cement mix for bonding

> Stage 2 : grouting with proportion of 1 cement : 2 sand mortar for concrete filling ;

cement content = 600 kg / m3

- Mortar material is supplied from batching plant and transported by Mixer Truck

DETAIL OF PIPE INSTALLATION

PIPE POINT PATTERN

Before Lining Concrete work begin, Steel pipe dia 1.5" thread end will be installed into the determined

points at the wall of sliding form. This pipe will be use for backfill grouting work. The execution of backfill

grouting can be started after the concrete lining reach 28 days.

Ø1.5 Ø1.5

120

80 50

30

120

120

100

100

kertas sak semen

A

B

DETAIL A DETAIL B

Concrete Lining

Backfill grouting

1.00

1.00

1.00

0.6 0.6

0.50

posisi lubang

0.6 0.6

(5) Contact Grouting and Curtain grouting

- Steel casing pipe dia. 50 mm shall be embed to the concrete lining where conformed with the

poins position for drilling and grouting.

- Commencing of Contact Grouting and Curtain Grouting after concrete lining have minimum

14 days age.

- Rotary Drilling will apply for drilling work

- Equipment and related drilling and grouting activities can illustrated in Figure 12.

- Arrangement of Drilling and Grouting is shown in Figure 13

Figure 12DRILLING AND GROUTING

WATER TANK

SAND

DRILLING

WT. PUMP

GROUTING

PUMP

CEMENT DRILLING

MACHINE

GROUTING

PLATFORM PLATFORM

RUBBER HOSE

RUBBER

HOSE

GROUTING

2.5 Inlet and Outlet Structure

(1) General Construction Method

- Inlet and Outlet Structure concrete type C, can be starting immediatelly when concrete lining

of tunnel for inlet or Outlet portion is completed.

- Due to limit of space at inlet foundation location, coffering use by Stone masonry.

- It necessary to provide dewatering system for inlet location,use Submersible Pump dia.2"

- To excavate the inlet foundation to elevation +92,60, use Excavator or Giant Breaker.

- After rock foundation have inspacted, immediately pouring the lean concrete.

- Installation rebar and Formwork

- All dimession and shape following the approved drawing.

- Concreting stages for walls or Piers per 2m high is applicable.

- Maximum drop of direct concrete placing is 2 m, and then use Concrete Pump.

- Outlet structure: rather enough for work space.

See Figure 14 Coffering at Inlet during excavation and construction

(2) Timing of Construction

- Timing of Construction expected in the dry season then discharge of river flow is minimum.

- Programe for execution of inlet,is very tight, design must be proper and fixed, then the resour

ces(man power, material and equipment) must be in adequate requirement.

3. Time Schedule for Diversion Tunnel Construction Works

3.1 Cycle Time Estimation

(1) Open Excavation

(2) Underground Excavation

Please see table 3.1.2 and 3.1.3

(3) Lining Concrete

*)Please see Detail time schedule

(4) Back Fill Grouting


(5) Consolidation/Curtain grouting


(6) Concrete Works


3.2 Detail Time Schedule

(1) Timing of commencement of each works and Critical Path

Please see attachment Detail time schedule

(2) Detail Time Schedule

Please see attachment Detail time schedule

3.3 Schedule for Equipment, Materials and Labors

(1) Equipment(Type, Number)

Please see annex 3.3.1

(2) Material (Item, Quality, Quantity)


(3) Labors (Schedule for Number of Employee)


35

Open excavation for inlet or outlet diversion tunnel usually done by combination of equipment, those are

: Excavator, Buldozer for excavating/loading and Dumptruck for hauling. The expected hourly production

is about 40 m3 , with normal dayworks ( 8 hr /day) the production will be 320 m3/day.

Excavation for diversion tunnel using short bench cut method . The area of excavation is divided into 2

section upperhalf section and lowerhalf section .

Lining concrete for diversion tunnel will be designed for 12 metre , except for curve section it will apply 6

metre. Basically two (2) centre/ sliding form will be installed for lining work. Cycle time for lining work is

divided for upper section and invert.

The cycle time is calculated based on the production of major equipment (excavator): 40 m3/hr ~ 320

m3/day . Production for 1 month will be = 8,000 m3

4. Quality Control and Progress Control of the Works

(1) Survey Works

Prior to commencement of excavation, temporary bench mark and refernce point to be set up at

each portal area of tunnel. The points shall be places where no damage or movement are expect

and well protect.

During tunnel excavation line and level marked by painted nail on the shotcrete surface, will be

setting up as near from the cutting face, that could be based of works.

The important marking reference shown as :

(2) Laboratory and Testing

No Work Activity Type of Test Remark

1 Drilling and Grouting Water Pressure Test -1 Stage = 5 m', 5 pressures/5minutes.

Washing and Testing - Test pressure

2 Shotcrete Material Test - Water shall comply Clause 9.7.

- Aggregates shall comply Clause 9.5.

Trial Test - Field trials,horizontal&Vertical,comply

to ASTM C 42.

Sampling - Compresive strength test comply to

ASTM 109.

3 Rockbolt Pull out - 80% of Cracking load.

4 Concrete Material - Cement, by factory

- Aggregate shal comply to Clause 9.5.3,

and Clause 9.5.4.

Concrete Test - Shall comply to Clause 9.14.

TEMPORARY

TEMPORARY LEVELLING POINT

IF REQUIRED

DESIGN 2,80 m'

₵ TUNNEL

DESIGN 2,80 m'

TEMPORARY

METHOD STATEMENT - Brantas...

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