Design and Construction of Piled Foundations for Additional Columbarium at Diamond Hill, Po Kong Village Road, Kowloon, Hong Kong. Contract No. PI R302

BP21

: 20061023

(BP21)(A/15)

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BP21

BP21

1. : BP21, (Grid) A/15 ; : +58.11mPD, (Grade III) ; : +74.783 mPD. ; : +57.08 mPD. ; : 22.4 ; : 14.7 ; : 15.7 ; : 6.755 ; : 9/10/2006, (Founding) : 16/10/2006 ;

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(23/10/2006) , , , , ; , , 45 ; 540, 52 , 1 35; 6, (Casing), , , ; 620, (13.9), 2 ; 630, , ,

, 38Y25 , 3.5 ; , , ; (Base Spacer), ;

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, ; , RCD ,() ; () ; ASD,

(1) (Spacer), 46, 68 , (Spacing)2.71.5 , ; 1, 1.5 ; , 1135 , 1 246 ; BP32, 34, ; 2/3, (Starter), (oscillator)(Casing), ; , 2, 3, ;

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(2) (Tremie Pipe), 2 ; , , ( ) ; , (Starter), (oscillator)(Casing), ; ,, , 2 ; , , , ;

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(1)a) b) c) d) 3 90o Check Setting Out Casing 1 c.) d)

e) R.C.D. Rock Socket

f) g) h)

(2)i) j) k) m) 200mm 2m

4m n) p) p)

q) Cut off level 0.8m

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Bored pile Detail38Y25 : 15.86

:1850 mm

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(4)

ASD(1)

Remedial Proposal for Bored Pile BP21 Removal of Poured Cement Grout and ConcreteRemove the Cement/Concrete within the steel casing with soil grab; Set up the RCD Rig; Further cleaning for the remained concrete with Reverse Circulation Drilling Method.

Base Cleaning Clean the pile base using standard air lifting method; Measure the pile founding level to ensure all cement & concrete had been removed. the sequence of steel cage installation shall be in accordance with our method statement; For prevention of cage up-lifting during concreting, the following measures will be employed: 1 no of Y25 Steel Ring will be added in the cage below the top of reinforcement bar at 300mm; 2~3 nos. of Y25 steel bar will be fixed on the top of vertical bar of steel cage and extend to the top of steel cage. The extended Y25 steel bar will be welded by tack weld on the casing before concreting. Additional roller spacers will be added to the steel reinforcement cage in order to stabilize the cage in the pile hole; i.e. 4 nos. spacer increase to 6 nos. spacer, or 6 nos. spacer increase to 8 nos.

Installation of Reinforcement Cage & Sonic Tube

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ASD(2) Concreting The sequence of concreting will be in accordance with our method statement. After the app. 60% completion of concreting, The casing should be rotated to ensure the interface between the casing and concrete detached; Extract the top segment of steel casing and the toe of casing shall be maintained with a depth of app. 3m below the concrete surface; Extract the Tremie Pipe and the base of pipe shall be maintained with a depth of app. 2m below the concrete surface.

(1)

Proposed Rock Head : + 58.11mPD

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(2)

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