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GENERAL DESCRIPTION
Project Information
The p rojectr c oadT Konnectsd t Kbongp ohmumt C istricts o ratie rovince f he ambodia, tretching along t n he torthern,K p To r ratiep o a crovince a he t oadf asses n omfortable lignment hrough lat/wavy t e r r a i n a l o n g t h e t o e o f h i l l y l a n d F o u r ( 4 ) r a t h e r s h a r p c u r v e s a l o n g t h e r o a d a r e c o n s i d e r e d n o n - c r i t i c a l d u e t o a d e q u a t e s u p e r - e l e v a t i o n o f t h e r o a d w a y a n d a p p r o p r i a t e s i g n a g e T h e t r a f f i c o n t h e road is a medium mix of private cars and quite heavy trucks that contribute mainly to the road wear.
The P R.377a P ondR aR377Al i K f p CIP T rel ocatedo t P i n3 ratiek rovince he ength f he R377 s 5.00 m and the PR377A is 13.593km The location of the packages is shown in Figure-1
Figure 1: Location of Contract Package on CW-3(PR377 & PR377A)
Project Objective
The o bjectiveo t p i ft ehe c roject e s uo o tnsurer ontinuedn a ffective se f he ehabilitated ational nd p r o v i n c i a l r o a d n e t w o r k i n s u p p o r t o f t h e e c o n o m i c d e v e l o p m e n t i n C a m b o d i a I t w i l l d o s o b y i mproving the insti tut ional and technical capacit y of t he Minist ry of Publ ic Works and Transport for r o a d m a i n t e n a n c e p l a n n i n g , b u d g e t i n g a n d o p e r a t i o n s a s w e l l a s b y e x p a n d i n g o f s t r e n g t h e n i n g maintenance activities.
The p rojects t c eeks t c o ontributea r a m o ultivatingc w t s oad sset anagement ulture ithin he ector b y : ( i ) e x p a n d i n g m a i n t e n a n c e o f t h e n a t i o n a l r o a d i n f r a s t r u c t u r e n a t i o n w i d e a n d f a c i l i t a t i n g i n t e r v e n t i o n s i n p r i o r i t y a r e a s , ( i i ) a l l o c a t i n g a d e q u a t e m a i n t e n a n c e f u n d i n g d u r i n g t h e b u d g e t i n g p r o c e s s ; ( i i i ) k n o w l e d g e b u i l d i n g i n M P W T o n r o a d n e t w o r k m a n a g e m e n t , m a i n t e n a n c e t e c h n o l o g y and c ontractm aanagement;( p s i nd iiv)c rivateb aectorp nvolvement n ompetitive idding nd erformance quality.
Pr oje ct i s expe ct ed t o bri ng si gnif ic ant bene fi t s to l oc al resi de nts i n si x Ca mbodi a n provi nce s,
Kampong c T hham,P K bongM hmum,R a ratie,S t p ondulkiri,b r atanakiri nd tung reng rovince; y educed t ra vel t im e s and cost , l ess ar duous jour neys a nd bet te r c onnect i vi ty a l ong the nat i onal roa d net work.
It is intended that the benefits to local populations are maximized, and to ensure that the benefits are shared by local communities.
Topography and Climate
The t opographyi t p a ni mhe f rojectw s hreas s a ainlyt r e lat ith ome illy ections nd he oad levation varies f mrom 2 inimumt m 5 3.52m T mo aximumt i a 0.95meter.4 t he aximum emperature s round 0°C, he annual temperature fluctuates more than 10°C and from 6 – 7°C in a day In hot weather the absolute high temperature may be up to 39°C (in April) By contrast, in January the absolute low temperature may descend to 16°C.
Rainfall Records
The a vailableh ydrometeorologicald s a r a o f atat K uchP s ainfall re btained rom he ratie rovincial
D e p a r t m e n t o f W a t e r R e s o u r c e s a n d M e t e o r o l o g y ( P D o W R A M ) T h e r a i n f a l l s t a t i o n i s l o c a t e d a t ( X = 6 1 0 9 7 6 , Y = 1 3 7 9 7 2 8 ) T h e d a t a r a n g e d f r o m 1 9 8 0 t o 2 0 1 9 i s c o n s i d e r e d t o c o n d u c t f r e q u e n c y a n a l y s i s f o r h y d r o l o g i c m o d e l i n g T h e 2 4 h r m a x i m u m a n n u a l r a i n f a l l o v e r 3 d e c a d e s w e r e e x t r a c t e d f o r t h e a n a l y s i s a s s h o w n i n F i g u r e 4 1 a n d 4 2 b e l o w F r o m t h e f i g u r e b e l o w , i t ’ s c l e a r l y o b s e r v e d that the highest rainfall over the period was in the year of 1988 with a value above 250mm, followed b y t h e y e a r o f 1 9 8 2 a s t h e s e c o n d h i g h e s t w i t h t h e p r e c i p i t a t i o n o f a b o v e 2 7 0 m m T h e y e a r 2 0 0 9 i s o b s e r v e d t o h a v e a b o v e 1 5 0 m m w h i c h w a s t h e h i g h e s t r a t e o v e r t h e 1 0 y e a r a f t e r 1 9 9 2 a n d i t w a s r e v e a l e d d u r i n g t h e K e t s a n a s t o r m I n 2 0 0 1 w a s n o t e d a s l o w e s t r a i n f a l l , i t ’ s r e f l e c t e d t o t h e Drought period.
Figure 2-2 Daily Rainfall Ditribution in Kratie 1980-2019
DESCRIPTION OF WORKS
Package CW3-PR377: PK0+500 ~ PK35+500, L=35.000km
This s ectionr c oadK C onnectst t S d ratie i K ityP o 3 he k amborT istrict n ratie rovince, 5.000 m he main w corks o onsistingA C ( f W sphaltC 5 oncrete+ A B AC)C 2 earing ourse cm ggregate ase ourse 0cm overlay, additional concrete pavement for market area and intersection area, i mprovement of erosion section and flooding section, installation of Concrete U-drains, Open side drains and Outlet Nine (9) new bridge construction and One (1) new box culvert.
Table-1 Detailed description of the project scope for CW3-PR377
Nine (9) New Bridges Bridge No.02, 03, 04, 05, 06, 07, 09, 11, 12
One (1) New Box Culvert PK13+327.00
Two (2) Pipe Culverts PK16+226 (New) and PK33+580 (Extension)
The proposed bridge works cover a section of Provincial Road No.377 (PR377) from PK0+500 to P K35+500P R rovincial3 s i l oada U 77 oectionM R st aocatedt long pstream f ekong iver he cross hree d i s t r i c t s i n c l u d i n g K r a c h e h ( K r a k o r c o m m u n e ) , C h e n t r B o r e i ( K r a k o r , T h m a K r e a e a n d S a m b o k communes) and Sambour (Sambour commune) Kratie province.
Quantity of Bored Piling
The p ackageP i R377n n d ncludeB i wine t ewp f esign d ridges,f n hich, he ile oundation esigned or each bridge is bored pile with diameter D500.
E s t i m a t e d q u a n t i t y ( b i d d i n g q u a n t i t y ) i s a s f o l l o w s B u t t h e y a r e o n l y f o r r e f e r e n c e T h e des ign quant i ty wi l l be made fr om approve d w orki ng drawi ngs T he a ctual const ruct i on quanti t y will be shown on As-built Drawing.
Bridge No Description Unit Quantity
BR-02 C.I.P RC Pile, Dia.500mm m 1108.80
BR-03 C.I.P RC Pile, Dia.500mm m 982.80
BR-04 C.I.P RC Pile, Dia.500mm m 819.00
BR-05 C.I.P RC Pile, Dia.500mm m 501.00
BR-06 C.I.P RC Pile, Dia.500mm m 363.60
BR-07 C.I.P RC Pile, Dia.500mm m 298.40
BR-09 C.I.P RC Pile, Dia.500mm m 363.60
BR-11 C.I.P RC Pile, Dia.500mm m 281.60
BR-12 C.I.P RC Pile, Dia.500mm m 251.60
Standards and technical specification related
OCMA DFCP4 Drilling fluid material -bentonite
OCMA: Oil Company Material Association
API-S 13A Specification for Oil -Well Drilling -Fruid materials
(API-S: American Petroleum Institute Standard) CAM PW 04-102-99 Bridge Design Standard (Cambodia, 2003) (AASHTO, 2002) Standard Specifications for Highway Bridges
- Section 5.1: Concrete of Specifications - Section 5.14: Boring Piles of Specifications - Section 5.2: Reinforcement of Specifications
3 Geological condition and hydraulic condition
According to Boring log documents
ORGANIZATION CHART
Organization chart is shown below:
MANPOWER AND EQUIPMENT
For the construction of bored pile, the Contractor will divide into the construction teams, each construction team will be mobilized personnel and equipment as described following.
Note: This manpower will be increased according to the site requirements
Item Name Unit Quantity Technical data
1 Construction machine for cast- in-place bored piles No 01 ≥40mdeep, D500mm
5 Cutting machine Set 01 For Rebar
10 Guide Frame on the land Set 01 H200
Note: This equipment will be increased according to the site requirements.
MATERIAL, ARRANGEMENT OF SITE
Material
Bored p s ilesb c hall i ae onstructedw t d s n occordancet d u t ith he etails hown n he rawings sing he class of concrete noted on t he drawings and in accordance with Speci fication Concret e and Concret e Structures
Concrete shall be mixed and placed in accordance with the applicable provisions of Section 5.1 Concrete of Specifications.
The slump is between 17+/-2cm (15-19cm) for bored pile concreting works.
T e m p o r a r y c a s i n g s s h a l l b e f r e e f r o m s i g n i f i c a n t d i s t o r t i o n T h e y s h a l l h a v e a u n i f o r m c r o s s - s e c t i o n t h r o u g h o u t e a c h c o n t i n u o u s l e n g t h D u r i n g c o n c r e t i n g t h e y s h a l l b e f r e e f r o m i n t e r n a l projections and encrusted concrete which might prevent the proper formation of piles.
4 Bentonite and Bentonite Slurry (Drilling Fluid)
T h e c o n t r a c t o r e x p e c t s t h a t a l l b r i d g e s ( c o n s t r u c t i o n o f b o r e d p i l e s) w i l l u s e C a s i n g p i p e s a n d bentonite solution to reinforce the hole walls.
D e p e n d i n g o n g e o l o g i c a l , h y d r o l o g i c a l a n d e q u i p m e n t i n o r d e r t o c h o o s e m e t h o d o f s t a b i l i z e b o r e d h o l e d w a l l a n d s u i t a b l e s o l u t i o n T h e s o l u t i o n i s c h o s e n b a s e d o n t h e c a l c u l a t i o n p r i n c i p l e o f t h e b a l a n c e b e t w e e n h o r i z o n t a l p r e s s u r e o f s o l u t i o n i n t h e h o l e a n d p r e s s u r e o f g r o u n d a n d w a t e r a r o u n d t h e h o l e w a l l I f d r i l l i n e a s y e b o u l e m e n t c o n d i t i o n , t h e p r e s s u r e o f s o l u t i o n m u s t b e k e p t bigger than horizontal pressure of ground and water around the hole.
If horizontal pressure of ground and water around the hole (by weight of equipment or adjacent project…) is hight then must be used casing to anti eboulement Length of casing must be calculated base on the principle that mentioned above.
Immediately prior to mixing Bentonite shall be in accordance with Specification DFCP4 of the
Oil C ompaniesM A aterials( F ssociationM B oDrillingt A P luid aterials entonite), r he merican etroleum
W h e r e c h e m i c a l l y c o n t a m i n a t e d g r o u n d w a t e r o c c u r s , s p e c i a l p r e c a u t i o n s s h a l l b e t a k e n t o modify the bentonite in all respects for the construction of piles.
Before drilling operations commence, the drilling fluids used for borehole stabilization must be thoroughly tested to meet specific gravity and viscosity criteria These parameters ensure the stability of the borehole, minimizing risks and ensuring drilling efficiency.
Sand Content; Shear strength; PH.
Name of target Features Checking measures
1 Specific gravity 1.051.15g/cm 3 Hydrometer or bomemeter
Testing sequence of bentonite liquid as follows
Before starting of drilling work
Interval 4 to 6 hours during excavation.
After cleaning bored hole at the first time.
After cleaning bored hole at the second time.
Circulation t f b ank l ors entoniteb c t diquid p whall a pe hecked imely uring iling ork nd recipitated material in tank such as sand or mud shall be removed adequately.
Site Arrangement
During t c he onstructiono b p t wf b mored oiling,t t rafficb T ill e aintained n he emporary ridge he contractor w i pill nstallf s srotectiven l aences,w t gign t ystems,o b ight ights nd orkers o uide raffic n oth sides of the bridge
2 Plan for supply of power, Water, And Ful, Etc.
The contractor will register to use the local water source for production.
Where it is not available, using water shall be transported to the site.
Local e lectricn w b etworkc i t illp e onnectedp a c n t he ower-available lace nd onsidering he sustainability o c ft gonstruction,s s b p he a a senerating s o p et hall e repared s tandby ource f ower in c aseo p ff owerW i failure.t c wherel e t nails to g onnect s ith ocal lectric etwork, he enerating et shall be used.
The f ixedt elephonesa I s b ind nterneti P M hall O e Knstalled n roject anagement ffice; ey personnel s b shall w e c uppliedp t f ith t iell ahonese o acilitate he nternal nd xternal communication.
Supply Sources of Major Materials
Given t q he o muality i e f a ateriala t t ps nsuredo b u ondl dhere o he rinciple f est se f ocal materials, t m a oe ake i n xtensiveo m s nvestigationp t c n aterial ources, rices, raffic onditions, means a c ndf a gosts e or a t ood c conomicC t ndb m echnicala omparison hoose he est aterial nd deliver t a hem t ccordingp I a to t lans.m w n additions b t o he aterials hich re upplied y he
Employer, a h sphalt,s s bigh p trengthw b teelb wars, b m re-stressb ire, ridge earings ill e et y purchasing t i C hemM on f hina.a o w bostp f l uel t rnd w ilb ill e urchased ocally, he est ill e purchased from China.
We h aver l icha t abor r nd w echnicianc b d t teservess a p a hich an e elivered o he ite s lan, nd we can also recruit some labors locally.
CONSTRUCTION OF BORED PILING
Construction Procedures
The construction procedures are as below.
Inspection - Center of casing - Vertically of casing - Elevation of casing
Inspection - Drilling slurry (Bentonite) - The depth of hole - Geological strata
Inspection - The depth of hole - Vertically of hole - Diameter of hole
Inspection - Drilling slurry (Bentonite) - The depth of hole - Sediment
Inspection - Rebar Cage (at yard) - The connection
Inspection - Length of tremie pipe
Inspection - Drilling slurry (Bentonite) - The depth of hole - Sediment
Inspection - Slump of concrete - Taking sample - Level of grout rise - Level of cut pipe concrete - Level of top concrete - Quantity of Concrete
17 Pile Head Treatment 11 Clean the hole (the 2nd time)
14 Ultrasonic, core test 15 Grouting sonic pile 16 Static load, PDA test
8 Clean the hole (the 1st time)
10 Install the tremie pipe 1 Preparation of Work Prevent the traffic accident
2 Mix drilling slurry Difine the geological strata
Checking specified of drilling slurry 3 Staking out the pile center
4 Locate the drilling machine Define the pile center and area to lacate of drilling machine
Step of works preparation of works pouring concrete
Bentonite install rebar cage vibrator
A install casing clean the hole (1st time)
Design level of tip pile
Bentonite, sludge install tremie pipe
3 steel tube 2 equipment for outer 1 equipment for inner
A - a removel casing pipe ghi chó:
5 rebar cage 4 dredge humus bucket 3 Drill bucket 1 casing pipe, length 6 m.
10 air tube 11 funnel for concrete
8 tip of pump pipe 9 tube for take back 6 tremie pipe location of pile center of pile stake
Design level of tip pile Design level of tip pile
Design level of tip pile
Design level of tip pile clean the hole (2nd time)
Preparation Ground and Setting out Pile Location
1 Preparation Ground construction on land
- L o c a t e a b u t m e n t a n d p i e r f o u n d a t i o n , c o n s t r u c t i o n s e r v i c e r o a d t o l o c a t i o n o f a b u t m e n t a n d pier, leveling existing ground up to construction level.
- Ensure drainage in case of heavy rain.
2 Layout of drilling location diagrams
- Each drill machine is arranged in a certain area to avoid entanglement in construction work.
- Arrange drilling sequences from the inside out to avoid the situation that the drill truck runs on top of the pile to finish pouring concrete.
- Side-by-side piles are drilled at least 24 hours apart after concrete pouring is completed.
Pipe center determination involves surveying using approved benchmarks with a total station The marked center points, specified in drawings, should be arranged in suitable areas to prevent obstruction during construction activities.
Temporary casing setting
- P r i o r t o t h e c o n s t r u c t i o n , a l l t h e m a c h i n e s , d r i l l i n g m a c h i n e s , c r a n e s , a n c i l l a r y e q u i p m e n t will be accepted by the Engineer.
- C a s i n g s h a l l b e m a n u f a c t u r e d a t w o r k s h o p i n a c c o r d a n c e w i t h d r a w i n g d e s i g n , b a s e d o n conditions o g f b eologicaln p l oreholea g earbyl a d ile l ocation nd round-water evel t rilling ocation.
E l e v a t i o n o f t o p c a s i n g w a s i n s t a l l e d h i g h e r t h a n t h e h i g h e s t w a t e r l e v e l 2 m a n d h i g h e r t h a n t h e ground c onstruction0 T c 6m.w s the u ontractorsw l f eill g urvey he nderground ater evel or ach roup of pile and submitted to Consultant before two days to determine stop level of bentonite in bored hole L oevelc e fm asinge t p nd o ustf c nsureh t hea ressures p f luid olumn igher han ctive oil ressure a n d c o n s t r u c t i o n l i v e l o a d o u t s i d e T h e r e f o r e , l e n g t h o f c a s i n g p i p e w i l l d e p e n d o n g e o l o g i c a l conditional of each abutment and pier of bridge.
- Temporary a i unti-pipet p t ws osedt b o arotectt t o t hep a all a f he orehole t he op f he ile, void ny s u r f a c e l a n d s l i d e s a n d a t t h e s a m e t i m e f a c i l i t a t e t h e c o n s t r u c t i o n p r o c e s s , t h e a n t i - p i p e m u s t b e placed vertically and inspected.
- The contractor will be used casing pile with length of casing: 6m, thickness 10mm, diameter o f c a s i n g 6 0 0 m m f o r b o r e d p i l e d i a m e t e r 5 0 0 m m L e n g t h o f c a s i n g p i l e m a y c h a n g e f o r s u i t a b l y with actual conditional on site.
- B e f o r e s e t t i n g , t h e c a s i n g s h a l l b e f r e e f r o m s i g n i f i c a n t d i s t o r t i o n T h e y s h a l l h a v e u n i f o r m cross-section throughout each continuous length.
The casing will be set at the 4 exact point by total station as below, mark by 4 steel pile. casing point 1 point 3 total station point 2 point 3
Temporary casing will be set by vibration hammer.
Using Drilling Bit to make a hole with 1m depth Next, crane will load of casing and put in bored hole at exact center point.
Using V ibrator-hammert c t c a so lampt m v he oasingp o c nd tarting o ake ibration n oint f asing t o p i n t u r n i n g c i r c l e , t h e n v i b r a t o h a m m e r w i l l b e u s e d t o i n s t a l l t h e c a s i n g c o n t i n u o u s l y t o reach the designed level.
During driving of the casing, its location and verticality will be checked by the total station.
Tolerance from horizontal direction < 8.0 cm
Bentonite
Bentonite solution effectively transports drilling debris from the borehole bottom to the solution pit, preventing borehole collapse Consequently, continuous solution presence in the borehole is crucial, even during work stoppages due to weather or overnight.
- Depending on geological, hydrological and equipment in order to choose method of stabilize bor ed hol ed wa l l a nd suit a ble solut i on The sol ut i on is c hosen base d on t he ca l cul at i on pri nci pl e o f t h e b a l a n c e b e t w e e n h o r i z o n t a l p r e s s u r e o f s o l u t i o n i n t h e h o l e a n d p r e s s u r e o f g r o u n d a n d water a roundt h w heI d iolee e all cf rill t pn asyo s boulementm b ondition, he ressure f olution ust e kept bigger than horizontal pressure of ground and water around the hole.
- D u r i n g t h e d r i l l i n g p r o c e s s , i f t h r o u g h a l a r g e p e r m e a b l e l a y e r , w a t e r l o s s i s f o u n d q u i c k l y , bentonite must be added to the solution for waterproofing.
- B e n t o n i t e s l u r r y i s u s e d t o s t a b i l i z e h o l e w a l l w h e r e i s e a s y e b o u l e m e n t f o r d r i l l i n g equipment, must be kept the humus does not accumulate in bottom of bored hole Take humus out o f h o l e m u s t b e e n s u r e d t h e s t a b i l i z a t i o n o f h o l e w a l l d u r i n g c o n s t r u c t i o n I f t h e u n d e r g r o u n d water level goes up, density of solution should be increased by high density substance like barit, magnetic sand.
- Che cki ng bent oni t e sl urry f rom m ixi ng unt i l f ini sh c onst r uct ion e ac h pil e , consi sts of adj ust t h e s u i t a b l e v i s c o s i t y a n d d e n s i t y T h e s o l u t i o n c a n b e u s e d c i r c u l a t i o n d u r i n g c o n s t r u c t i o n i f i t ensures the suitable index but do not exceed 06 moths.
- I f u s e p o l y m e r i c s o l u t i o n o r a n o t h e r c h e m i c a l t o s t a b i l i z e h o l e w a l l , i t m u s t b e t e s t e d t h e effective to environment at site and disposal place.
- Before s d tart b rilling,l s entoniteb c a miquids t houlde c e hecked nd ade ure hose nough riteria.
B e n t o n i t e s h a l l b e k e p t i n d r y s t o r e B e n t o n i t e s u s p e n s i o n s h a l l b e m i x e d b y s p e c i a l i z e d m i x e r Water should be checked by laboratory before start mixing bentonite
Targets of initial features of betonite solution
Name of target Features Checking measures
1 Specific gravity 1.051.15g/cm 3 Hydrometer or bomemeter
- During drilling the bored hole, the bentonite must be continuing supply to the hole and make sure that elevation of bentonite liquid is higher than elevation of ground water.
1 Method proposed to mix, supplying and recycling bentonite.
- The general requirement of Bentonite shall comply with technical specification.
Detail of method to mix Bentonite suspension.
- C o m p o s i t i o n a n d m i x t u r e d e s i g n : D e p e n d o n k i n d o f B e n t o n i t e p o w d e r , t h e C o n t r a c t o r s h a l l design d ifferentm A m ixtures.s b i ll b ixturesb u a halls b a e nspected efore eing sed nd hall e ccorded with technical specification "Test on Slurry".
- M e t ho d st at e m e nt m i xi n g: B e n t on i t e sh a l l be m i x ed b y m i x i n g m a c hi ne a n d st or e d i n a t a nk which supplies to bore hole.
Supplying and recycling of Bentonite suspension
- Supplying: Before pumping, the Quality Control team shall check all required characteristics of Bentonite suspension under Engineer’s witness.
- Bentonite s uspensions b p i bhallh u e i umpedl r t 2ntoa gore ole ntil t’s evel each o m bove round water level or river water level
- Depending on soil layers, the Construction team could adjust the mixture by adding additive to meet to requirement.
- D u r i n g i n C l e a n i n g B o r e d h o l e o r p l a c i n g c o n c r e t e , d r i l l i n g F l u i d s u c k e d b a c k t o d e - s a n d e r and recycling to clean it before being supplying tank.
Inspecti on Bentoni te solution at the d ep th of about 0.5m from the bottom of bored hole as requirement
Bentonite samples are collected using a specific device with a lid that opens and closes The device is dropped to the bottom of the borehole on a wire When reaching the desired depth, the lid opens to allow the bentonite to fill the device The lid is then closed, and the device is pulled back up to retrieve the sample.
Boring works
- The sequence of boring shall be according with drawing of work organization design During b o r i n g , v e r t i c a l a l i g n m e n t o f t h e d r i l l r o d s h a l l b e c h e c k e d b y p l u m b l i n e a n d t a p e o r t h e o d o l i t e f r om t w o d i r e c t i o ns p er p e nd i c ul a r t o e a c h ot he r B o re d p i l i ng sh a l l be e xe c u t e d c on t i n uo us l y I n case of condition of soil varies, viscosity of Bentonite suspension shall be adjusted.
- D uringt d hew rillings s s orks,b m oila r tratum c hallt c ae onitored nd ecorded arefully o heck ctual soil condition under inspection of the Engineer.
- S o i l st ra t um sh a l l be t a ke n s am pl e a nd m on i t o re d e a c h 2 m o f d e pt h t o co m p a re w i t h t h e l og d a t a d u r i n g e x c a v a t i o n I f t h e r e i s a n y d i s c r e p a n c y b e t w e e n e x c a v a t e d s o i l a n d l o g d a t a d u r i n g excavation, the Construction shall report it to the Engineer.
- B asedo t r n ohes sesultst df oilt b amplep t estingE w during t he oring rocess, he ngineer ill ecide o the pile toe level If necessary, the pile should be extended or reduced, subject to the approval of the Consultant.
- After inspection co-ordinate of pile center, we prepare of plan, materials and equipment.
- Install Drilling machine, the Contractor shall check usually by Ruler to ensure the stability.
- Inspect the vertical alignment of drill rod
- Inspect the drilling fluid (Bentonite suspension)
- Inspect the elevation of pile bottom.
- Characteristics of Bentonite suspension shall be as requirement.
- D u m p i n g l o c a t i o n w i l l b e c h o s e n b y c o n t r a c t o r t h r o u g h t h e a p p r o v a l o f l o c a l a u t h o r i t y , a n d t he n su bm i t t e d t o t he e ng i ne e r fo r a p pr ov a l D i s po sa l so i l sha l l b e k e pt a t si t e t o b e c om e ha r de n before removing to permitted location.
- Contractor w m illb onitors d entonitet c uspensionp t p i f uring he onstruction eriod o revent t rom being over flown to the site and the neighborhood.
- During boring, vertical alignment of the drill rod shall be checked.
- In case of stop working for a long period, drill bit shall be placed outside of bore hole.
- F o r a n y c o l l a p s e o f w a l l o f b o r e d h o l e h a p p e n e d i n d r i l l i n g , C o n t r a c t o r t o g e t h e r w i t h t h e Engineer shall consider setting forth overcoming method
- For a dny oamageD m f c rilling w r achine,o m a ontractoro a s a ill epair r obilize nother ne s oon s possible.
- I n c a s e s o i l a t t h e b o t t o m p i l e i s s c r a m b l e , c o n t r a c t o r s h a l l u s e B u d g e t d r i l l i n g t o t a k e o u t disturbed soil and carry out clean bottom pile in accordance with the technical specification.
- A f t e r e a c h t i m e d r i l l i n g i s a b o u t 5 ~ 7 m d e p t h t h r o u g h o u t t h e l e n g t h o f b o r e d h o l e , t h e contractor shall check verticality of bored hole during drilling-by-Drilling Machine.
- The contractor shall use dredge humus Bucket which has the shape of tip bucket like drilling bucket to dredge the disturb soil.
The reason cause falling in of drilling hole wall and solution methods:
The main reason in static:
- Length of casing is not throughout the complex geology.
- Pressure of bentonite solution is not enough.
- High pressure of underground water.
- Gravel layer has underground water or not which cause to lose bentonite solution.
- Density and concentration of bentonite solution is not enough.
- Drilling speed to fast cause the membrane has not formed in time yet.
The main reason in dynamic:
- Casing is deformed suddenly, or shape of casing is not suitable.
- Casing is deformed, ground is not stabilized when adjusting.
- Put the rotator on casing directly that cause to reduce cohesion of casing and earth.
- Membrane of solution is broken when installing rebar cage.
- Waiting f l tor f ongp cime ( orn lacingn e 2oncretet c t min t ormally ot xceed 4h) hat ause o ake he solution hydrate and the density is not meet requirement.
Method of precaution holed wall falling in:
- Adjust vertical of casing when installing.
- Control quality of bentonite solution closely when constructing.
- W h e n a p p e a r p r e s s u r e u n d e r g r o u n d w a t e r , i t h a d b e t t e r t o i n s t a l l t h e c a s i n g t h r o u g h o u t t h e layer I d f t rillingt g l ot hem t ravels l ayeri h bhat t s aked a he olution eak, t ad etter o top oing nd c o n s i d e r c h a n g e o t h e r m e a s u r e s F o r t h i s r e a s o n , d r i l l i n g w o r k f o r s o i l i n v e s t i g a t i o n i s v e r y important.
- Keep the drilling speed regularly comply with the technical specification.
- Check in g qu al ity o f b en to nit e s olu tio n regu larly du ring w ait ing fo r pl acing co ncrete in ord er t o h a v e t h e s o l u t i o n m e t h o d A v o i d b e n t o n i t e s o l u t i o n a c c u m u l a t e a n d h y d r a t e t o m a k e t h e hole wall fall in.
- When the drop-frame reinforcement shall be careful to avoid reinforcing bumps into the hole.
A f t e r r e l e a s i n g f i n i s h e d r e i n f o r c i n g c a g e t o m a k e t h e m o v e s o i l e r o s i o n , m i x i n g m e t h o d comm only used spray, then use this method of air, sand pump, etc mud to suck it up, thi s t i m e t o p a y a t t e n t i o n n o t b e e n p u m p i n g t o o m u c h p r e s s u r e t o a v o i d h o l e s a n d r u i n e d m a n y more.
- Change suitable bentonite solution if the old one is not meet requirement and take the old one out of hole.
- If the reason is not installing casing throughout the soft soil layer, the only contractor can do is continue to install casing throughout the soft layer and in hard layer 1m at least.
- If cannot install casing because of friction, use auxiliary casing to install by each segment in o r d e r t o r e d u c e f r i c t i o n Q u a n t i t y o f c a s i n g d e p e n d s o n d e p t h o f g e o l o g y I n n e r a u x i l i a r y c a s i n g h a s l e n g t h t h r o u g h o u t , a n d d i a m e t e r i s s a m e w i t h t h e i n i t i a l c a s i n g T h e s e g m e n t s auxiliary casi ng has length shorter than, it depends on capaci ty of machine t hat use to i nstall casing and diameter is bigger than 10cm layer by layer from inside to outside.
After d rillingh t d lole s oi esign t d eveld hallv nspectiono b he epth, iameter, ertically f ored hole by Koden test.
- Method statement for Koden test will be submitted separate document.
- Allowable tolerance of borehole depth 10cm.
Diameter and verticality of bored hole do not satisfy requirements.
- U s e d s i d e c u t e r o f d r i l l i n g b u c k e t t o c u t t h e p r o t r u d i n g s o i l b y m o v e b u c k e t t o d i a m e t e r o r v e r t i c a l i t y o f b o r e d h o l e d o n o t s a t i s f y r e q u i r e m e n t s a r e a a n d r o t a t e t h e b u c k e t t o c u t t h e protruding soil of bored holed wall.
Cleaning bored hole at the first time
- A f t e r d r i l l i n g t o d e s i g n e d d e p t h , t h e d r i l l i n g w o r k s h a l l s t o p f o r 3 0 m i n u t e s t o m e a s u r e t h e s e t t l e m e n t T h e s e t t l e m e n t w i l l b e d e t e r m i n e d b y t h e d i f f e r e n c e o f d e p t h b e t w e e n 2 t i m e s o f measurements after completion of drilling and after 30 minutes If the settlement exceeds the limit, the deposit shall be dredged by the bucket and treated until meeting the requirement.
- In case of height of sediment at bottom of bored hole is more than 2m, contractor should use Drilling Bucket to take out it before carrying out clean bore hole.
Method 1: Cleaning of Bored hole by Aspiring Pumping
- T h e c l e a n i n g o f b o r e d h o l e w i l l b e c a rr i e d o u t b y A s p i ri n g P u m p i n g c o n n e ct i n g w i t h T r e m i e p i p e t o a b s o r b s e d i m e n t a n d b e n t o n i t e s u s p e n s i o n i n b o t t o m b o r e h o l e a n d s u p p l y n e w bentonite to replace at the same time
- F i r s t l y , t r e m i e p i p e s a r e c o n n e c t e d t o g e t h e r b y t h r e a d e d h e a d t o b o t t o m p i l e w e d i r e c t l y c o n n e c t a s p r i s i n g P u m p i n g 9 0 m 3 / h w i t h T r e m i e P i p e L e v e l f o r i n s t a l l i n g T r e m i e P i p e i s belong t d os egreea b edimento b h t a t rottom s t f A ore p ole o djust easonably o hat ttractive ower is enough strong to attract sediment at bottom of bore hole
- Time for cleaning of bottom of bored hole in the first time is at least 2 hours.
- T h e C o n t r a c t o r b o r e d h o l e d c l e a n i n g b y r e v e r s e c i r c u l a t i o n m e t h o d I f c o n t r a c t o r s u s e o t h e r m e t h o d s o f c l e a n i n g , c o n t r a c t o r s h a l l b e s u b m i t t e d t o E n g i n e e r i n s e p a r a t e d o c u m e n t A f t e r finished cleaning, the sedimentation of tip pile should be checked again.
Targets of initial features of betonite solution
Name of target Features Checking measures
1 Specific gravity 1.051.15g/cm 3 Hydrometer or bomemeter
MUN AND BENTONITE RETURN SCREEN BENTONITE
Rebar cage installation
The fabrication of reinforcing steel is determined by the length of the form cage For cages exceeding 12 meters in length, fabrication is typically carried out in a workshop to ensure precision and quality control These prefabricated cages are then transported to the construction site for installation In contrast, cages with lengths less than 12 meters are fabricated directly at the construction site, allowing for greater flexibility and cost efficiency.
- Maximum length of rebar cage depends on length of main bar Rebar cage must strengthen to e n s u r e i t i s n o t o u t o f s h a p e R e b a r c a g e m u s t h a v e s u s p e n s i o n h o o k m a d e b y s p e c i a l s t e e l ; q u a n t i t y o f h o o k m u s t b e s u i t a b l e t o e n s u r e t h e r e b a r c a g e d o n o t c o m e o u t w h e n s u s p e n d i n g o n the casing
- Reinforcing l h t oops d ave w hem bamea s i iametero c t d ith i ain ar nd et nside f age, he istance s a b o u t 2 0 m , u s i n g w i r i n g t o c o n n e c t W h e n t r a n s p o r t i n g , l i f t i n g , u s e t e m p o r a r y s u p p o r t t o a v o i d transformation.
- Centering rebar cage by concrete spacer The spacer made by concrete will be fabricated and i n s t a l l e d a t t h e r e b a r b e l t s o f t h e s i d e o f t h e r e i n f o r c i n g c a g e T h e w i d t h o f c o n c r e t e s p a c e r d e p e n d s o n t h i c k n e s s o f c o n c r e t e c o v e r i n g l a y e r , i n n o r m a l l y i t ’ s 7 ~ 1 0 c m Q u a n t i t y o f s p a c e r comply to shop drawing in order to make rebar cage in center.
- C o n n e c t r e b a r c a g e b y l a p p i n g j o i n t - w i r i n g , l e n g t h o f c o n n e c t i o n c o m p l i e s w i t h d e s i g n a n d t e c h n i c a l s p e c i f i c a t i o n , i n n o r m a l l y i t ’ s 4 5 d T h e c o n t r a c t o r s h a l l h a v e m e t h o d o f m e c h a n i c a l i n order to ensure the rebar cage do not slide down when installing.
- Soni c pipe must be wi red t o the main bar, bot tom of pi pe is covered and set up at bott om of bored pipe, connect each segment by welding with sleeve in order to ensure the water do not leak i n t o t h e s o n i c p i p e T h e s o n i c p i p e m u s t b e e n s u r e d c o n c e n t r i c w h e n s e t t i n g u p L e n g t h o f s o n i c p i p e c o m p l i e s t o d e s i g n a n d t e c h n i c a l s p e c i f i c a t i o n I n n o r m a l l y , t h e t o p o f s o n i c p i p e i s h i g h e r than g roundl 1 evelA p 0-20cm.c s pfter i f lacingc w a oncrete,c t onic ipe s illed lean ater nd overed o avoid undefined object get in.
- Before lowering the cages to their positions, it is needed to recheck the level center point of the pile base.
- The lowest reinforcing cage will be put into the casing and temporarily fixed at section to be spliced with next reinforcing cage
- A f t e r c o m p l e t i o n of co nn e c t i o n of bo t h c a ge s , t he c on ne c t e d c a ge w i l l be pu t i nt o t he bo r ed hole in the same method as aforesaid and spliced with the next cage.
- C o n t r a c t o r w i l l c a r e f u l l y c h e c k a f t e r w e l d i n g t h e j o i n t s o f s o n i c t e s t t u b e T o d e t e r m i n e t h e q u a l i t y o f j o i n i n g p o i n t s a f t e r w e l d i n g , c o n t r a c t o r w i l l p u m p u p w a t e r i n s o n i c p i p e a n d c o r e drilling pipe, and if the water level remains unchanged, welded lines is up to the requirement.
- The Sonic test tube D50mm shall be put into the bored hole together with reinforcing cage.
- After installing last cage, used 4 rebar with D25~D28 with hook and fixed joint to the top of w e l l c a s i n g t o p r e v e n t s t e e l c a g e s f r o m b e i n g l i f t e d u p a n d s u n k i n t h e p r o c e s s o f c o n c r e t e placement
Secondary cleaning
Method 2: Cleaning of Bored hole by Air Compressor
+ Installing Tremie Pipe Dinto Bored hole; the Level of head of Tremie Pipe is 30 - 50cm from bottom of Bored Hole
PILE TIP ELEVATION EXISTING ELEVATION
+ Installing t T i he T ube P tnsidel t i remie2 l o bipe h of evelb o hat s /3 ength f ored ole rom ottom f
Bored Hole At the head of air tube, we install an air distributer.
+ Installing t c het aleaningt o T poperT c t opt hf tremiev o iipe; he leaning oper ave wo alves, ne s jointed w A Tith a oir i j ubec ndt r ne B s oints a hannel s i o ecycle entonite lurry dulterating oil n bored hole
+ When s tartingc b leaningh t h cored a ole,i b che igh w ompress ir s lown ontinuously ith
7-9kg/cm2 t b ensiont 1 m y a hec 0 p3/minutet a t t irt aompressor, assing he ir ube o he ir distributer W t c hen a iheo o ompresst a d uir bs hut i fw the ir istributer nder ored ole, t ill urn back t g ou d ot pp ueo d o rinciplep i af o ifferentialo T p Iressure nside nd utside f remie ipe t makes a a n p spiratea b ressureo b h t ta ottomb s f a ored ole o bsorb entonite lurry dulterating sediment following tremie pipe to de-sander flowing bentonite tank
+ During c leaningb h b a oredc oleb ys irc ompressor,i s t etonite lurry ontinuously s upplied o compensate i b hnsidei o torede l olea p n rdero B o s nsurei b evel nd ressure f entonite lurry n ored holed not change
+ Time o c f ileaningb 1 – 2 h s A y s t s ours.a c fterc toppingu o upply ir ompress, ontractor se measuring tape to check bottom level of bored hole for obtaining design level.
+ Cleaning w i c ork a sf onsideredw s a st binishingi l t 1hen a ediment t he ottom s ess han 0cm nd result of checking properties of bentonite being achieving with specification.
+ Sedimentation o b s fb c ored d houldc a ec heckedo b l uringi leaning nd riteria f entonite iquid s followed approval of engineer.
Concrete placing
- I m m e d i a t e l y a f t e r t h e a c t i v i t i e s f o r b o r i n g e x c a v a t i o n , p l a c e m e n t o f r e i n f o r c e m e n t c a g e a n d c l e a n i n g o f t h e b o r e h o l e h a v e b e e n c o m p l e t e d , t h e C o n t r a c t o r s h a l l r e q u e s t t h e E n g i n e e r ’ s approval for the commencement of concreting
- B e f o r e p l a c i n g c o n c r e t e , m e a s u r e s s h a l l b e t a k e n t o e n s u r e t h a t t h e r e i s n o a c c u m u l a t i o n o f silt or other material at the base of the bore
- O n c e t h e E n g i n e e r ’ s a p p r o v a l f o r t h e c o m m e n c e m e n t o f c o n c r e t i n g h a s b e e n o b t a i n e d , concreting s s whall d tarta c ithout I a belay w ndc ontinuously.w o d n oring hich ontains ater r rilling fluid the concrete shall be placed by tremie
- T h e c o n c r e t e w i l l b e d i r e c t l y p r o v i d e d f r o m M i x T r u c k o r t h e p i p e o f C o n c r e t e P u m p i n g machine (if necessary) into the funnel of tremie pipe.
- Design of concrete class will be submitted in separate documents
- The C ontractorw t t s illo c est f hee t lumpm C f oncretes b p or ach ruck ixer oncrete hall e oured when the Bentonite suspension meet the specification.
- T r e m i e p i p e s h a l l b e c l e a n e d a n d w a t e r t i g h t t h r o u g h o u t a n d e n o u g h t o b e u n d e r p r e s s u r e during pumping smooth on both inside and outside of the tremie.
- A c o n c r e t e p o u r i n g p i p e i s a s t e e l p i p e a n d E a c h s e g m e n t o f t h e t r e m i e p i p e i s a b o u t 1 5 m long The joint shall be watertight and easy assembled.
To ensure concrete quality on pile bodies, surplus concrete is casted to account for contamination at the top from bentonite liquid For bored piles with a diameter of 500 mm and pile heads inside casings, the concrete level should remain 100 cm above the cut-off level after casing removal, considering concrete sliding and effects from casing removal Therefore, before temporary casing removal, the surplus concrete height is recommended to be 1.5-2.0 m from the cut-off level or overflowed from casing tops However, the Engineer may adjust this based on site conditions.
- C o n c r e t e s h a l l b e t r a n s p o r t e d f r o m t h e m i x i n g p l a n t o f t h e C o n t r a c t o r o r o t h e r c o m m e r c i a l c o n c r e t e b y 6 - 8 m 3 t r u c k m i x e r t o s i t e T h e C o n t r a c t o r w i l l e n s u r e t h e t i m e f r o m m i x i n g t o pouring concrete is not allowed to be over 120 minutes.
- Before p clacing t t oncrete,p r t het b remieo b hipe i s eachesb l o he ottom f ored ole, t hall e ifted up for 20cm in order to keep the enough clearance to discharge concrete.
- T h e s p o n g y b a l l s h a l l b e p u t i n t h e t r e m i e , u n d e r t h e f u n n e l n e c k i s a b o u t 2 0 ~ 4 0 c m t o k e e p the concrete and Bentonite suspension separately.
- After c ompletiono t a p f het t bovep w rocedures,b l l s t het g remie ipe ill e ightly ifted o hat he ap be tw ee n the end of t r em ie pi pe and t he bott om of bor ed hol e i s 40cm i n the fi rst t im e of pl ac ing concrete.
- Concrete will be poured full funnel and then open the lip at bottom of funnel for concrete go into t remiep C ipe.s b poncretew i hall d e t lacedb s ithoutc k nterruption uring he oring olution an eep t he bor ehol e si des A ll c oncre te l orri es sha ll be chec ked f or t he sl um p as re gula t ion t o avoi d t he obstruction i t p n d remiet t d ipeso c uem oC he wrynesss b s f oncrete ortar oncrete orks hall e topped if t hel oevelp c f ilingi 1 h oncretet t c ls omp (ighere t hanc he ut-off evel f ile to liminate he oncrete mixed into boring solution during the construction of pile cap) However, stopped concrete works may be adjusted by instruction of the Engineer at the site depending actual condition on site.
- The concrete will be directly provided from Mix Truck or Pipe of concrete pumping machine ( i f n e c e s s a r y ) i n t o t h e f u n n e l o f t r e m i e p i p e a n d t h e c o n c r e t e s l u m p w i l l b e a s t h e a p p r o v e d m a t e r i a l d u r i n g p l a c i n g T h e b o t t o m o f t r e m i p i p e s m u s t a l w a y s b e s u b m e r g e d i n c o n c r e t e f r o m
- C o n t r a c t o r w i l l f a b r i c a t e f i l t e r n e t b y R e b a r D 1 0 , @ 1 5 0 m m w e l d i n g a t f u n n e l m o u t h t o prevent big aggregate (if any) fall inside tremie pipe
- To prevent concret e from bei ng stuck and jammed insi de Tremie pi pe, contractor will adj ust the speed of concrete placing suitably.
- Contractor should prepare rain - cover in case raining while placing concrete.
- Sampling concrete mixture should be conformed to the technical specification of project.
- Sampling position: at batching station and construction site.
- After c ompletiono p c f a tlacingr r oncrete,t t w s llb s he ecordst elated o his ork hall e ubmitted o the Engineer.
PILE TIP ELEVATION EXISTING ELEVATION
PILE TIP ELEVATION installation of tremie pile
- The contractor shall control the temperature of concrete is not exceeding 35 0 C.
Removal of temporary casing
- After c ompletiono c f f1 20 moncretinginutes,t c roms he b casing5 o b rhall e arried ut y otaty s y s t e m o f d r i l l e r o r v i b r a t i o n h e a d v e r t i c a l l y t o e n a b l e t h e s t a b i l i t y o f p i l e h e a d a n d a c c u r a c y o f pile axis.
- A f t e r c a s i n g f r o m 12 h o u r s , b o r e h o l e s h a l l b e r e s t o r e d b y f i l l i n g o f s o i l a n d / o r s a n d T h e s i g n b o a r d o f c o n s t r u c t e d p i l e s s h a l l b e s t i c k e d o u t t o f o r b i d t h e p a s s i n g o f v e h i c l e s t o a v o i d t h e damage of pile head and sonic test tube.
Method of grouting for Sonic test tube
- Grouting cement, sand and cement to fill the sonic test tube.
- High air compressor - Special grouting machine
- I n o r d e r t o e n s u r e t h e q u a l i t y o f g r o u t i n g i n t h e p i p e o b t a i n r e q u i r e m e n t s t r e n g t h , n o t segregate, not pock-marked The measure should be carried out the stage follow as:
+ Use air compressor to take water in sonic pipe out.
+ Prepare suitable grout follow the technical specification.
+ Use g routingm t f achineg i t po f ill t brout t t ntot o the p ipeT rom he ottom o he op f he ipe he grouting p i w ipe sg ithdrawinga t s t w raduallyt h o g ti she p ame ime ith he eight f rout n onic ipe.
With t p he oressurem g fl achine,a t m oravityg t s oadp wndb he obility f rout, he onic ipe ill e filled fully without the segregate and pock marked.
Test of bored pile
Method s tatementf S l t orU tatict w oadb s est,s ltrasonicd t t est ill e ubmitted eparate ocument o he consultant by the contractor.
Pile Head treatment
1 Work Flow of Pile Head Treatment:
After foundation pit excavation, surplus concrete at pile head shall be demolished and removed.
General working flow as follows:
* Survey Inspection for as built of pile such as cut-off E.L and eccentricity 4 Survey Actual Cutt-off Elevation
* Inspection of condition of concrete at cutt-off surface
* Completion of Grouting Sonic Tube
* Structure Excavation * M.S shall be made separately.
1 Survey and Marking at Cut-off Elevation * According to the approved working drawing
Acceptance Committee for Cast-in-place Concrete Pile
Sequence of Work Description of Checking and Inspection
2 Description of Work Sequence for Pile Head Treatment:
The description of sequence of work is as followings:
Inspection for mobilization by the Engineer
Survey and marking shall be carried out at designed cut-off elevation on pile.
C u t t e r s h a l l b e i n s t a l l e d a t a b o v e c u t - o f f e l e v a t i o n w i t h d e p t h a p p r o x i m a t e l y 3 c m D u r i n g cutting, special care to prevent damage re-bar of bored pile shall be paid.
S u r p l u s c o n c r e t e a b o v e c u t - o f f e l e v a t i o n s h a l l b e d e m o l i s h e d b y b r e a k e r a s s h o w n b e l o w i l l u s t r a t i o n T h e w e i g h t o f b r e a k e r 7 ~ 2 0 k g a n d a c t e d b y a i r p r e s s u r e D u r i n g d e m o l i s h i n g concrete, special care to prevent damage and bending re-bar of bored pile Loose concrete on cut-off surface and on re-bar above cut-off level shall be remove manually.
A s b u i l t i n s p e c t i o n s u r v e y s u c h a s c u t - o f f l e v e l a n d e c c e n t r i c i t y s h a l l b e c a r r i e d o u t w i t h attendance o t E f hes ngineer’sC o c urveyor.s s b i onditionb t f oncrete urface hall e nspected y he
The tolerance of cast-in place concrete pile is as followings:
Cut-off elevation of pile head: +20mm
Eccentricity: 10cm for diameter of bored pile
After completion of all scope of work for Cast-in-place Concrete Piling such as Bored PilingW o r k , S o n i c T e s t , G r o u t i n g S o n i c P i p e a n d P i l e H e a d T r e a t m e n t , a c c e p t a n c e c o m m i t t e e w i l l b e carried out per pier.
Other Hazard and Treatment
1 Stability of Crane in critical phases to be examined.
During the construction process, the crane may be unstable due to improper operation, so:
+ Crane operators must conduct inspection before use to ensure safe operation.
+ Only one person gives the signal.
+ The person giving the signal must always observe the package and the people around.
+ The signaler must always be within sight of the crane driver.
+ Emergency stop - Anyone can give this signal.
The crane driver must know the principles of instability and the specifications of the crane when operating.
The contractor will use a 25ton crane with the following specifications:
+ Maximum lifting height: 31.2 m + Maximum lifting angle: 800 + Maximum lifting capacity: 25000 Kg + Maximum working radius: 30.5 m + Minimum working radius: 3.1m + Rotation speed: 2.9rmp
All machinery and equipment must be checked and approved by the engineer before being put into use.
- S o l u t i o n o f w a s t e w a t e r w a s s o l v e d b y s m a l l t a n k f o r o v e r f l o w e d s l u r r y f r o m b o r e d h o l e d a n d e x c a v a t e d p o n d f o r o v e r f l o w e d s l u r r y f r o m e x c a v a t e d s o i l w h i l e e x c a v a t e d s o i l / m u d s h a l l b e transported by trucks to approved disposal area.
- Excavated p i t cond a ws ow ollect f t lle aste s a aste/slurryt p w rom he xcavated oil nd o revent aste slurry from expanding to other areas.
- During construction, all activities concerning to electrical work shall be stopped if raining.
- All electric boxes shall be protected by roof to prevent water from entering inside If concrete work is being carried out and it rains, activities shall be continued as usual with the plastic covers for the concrete Hooper and concrete mixing trucks
4 Broken Drilling Machine - Repairing work for broken machine will be carried out immediately by a mechanics.
QUALITY CONTROL
Reinforcement
- Reinforcement s c w hallt p omplyo S ith5 he rovisionso S f ection 2-Reinforcement f pecifications and shall be positioned as shown on the Drawings Main reinforcing bars shall be supplied in one complete l a engths t pnd, i hould e his s rove b a mmpracticable,a b ffectively pliced y ethod pproved y the Engineer.
- R e i n f o r c e m e n t s t e e l b a r s s h a l l c o n f o r m t o t h e m a t e r i a l p r o p e r t i e s s p e c i f i e d i n A A S H T O M 3 1 M , D e f o r m e d a n d p l a i n b i l l e t - s t e e l b a r s f o r c o n c r e t e r e i n f o r c e m e n t , G r a d e s 3 0 0 a n d 4 0 0 D e f o r m e d b a r s s h a l l b e G r a d e 4 0 0 , p l a i n r o u n d b a r s s h a l l b e o f G r a d e 3 0 0 B a r s s h a l l b e o f d i a m e t e r s 6 m m , 8 m m , 1 0 m m , 1 2 m m , 1 6 m m , 2 0 m m , 2 5 m m , 2 8 m m , 3 2 m m , a n d 3 6 m m , u n l e s s otherwise agreed by the Engineer.
- R e i n fo r c i n g s t e e l s t o r e d a t t h e s i t e s h a l l b e l a i d o n w o o d f l o o r s s o t h a t n o r e i n f o r c e m e n t s t e e l shall be laid upon or come in contact with the ground.
- If rainy or humid weather occurs or is anticipated, bars shall be stored under cover.
Bentonite
- Bentonite shall be in accordance with specification of Project.
- Bentonite shall be stored in the storage tank at site.
- Bentonite shall be mixed thoroughly with clean fresh water.
- T h e t e m p e r a t u r e o f t h e w a t e r u s e d i n m i x i n g t h e B e n t o n i t e s u s p e n s i o n , a n d o f t h e s u s p e n s i o n when supplied to the borehole, shall be not lower than 5˚C.
Concrete
- C o n c r e t e M i x i n g a n d D e l i v e r y : T h e m i x d e s i g n o f c o n c r e t e s h a l l b e i n a c c o r d a n c e w i t h t h e submitted by the Contractor and approved by the Engineer.
- P i l e s s h a l l b e c o n s t r u c t e d , i n a c c o r d a n c e w i t h t h e d e t a i l s s h o w n o n t h e D r a w i n g s , o f c o n c r e t e classes s pecified,p m roportioned,a p i a wixedt p nd o Slaced 5 n ccordance ith he rovisions f ection 1-
- The batching plant shall include separate bins for the cement, fine aggregate and for each size of c oarsea ggregate,a w f a s eighingc o d unnel, a nd t wcales o apable f etermining ccurately he eight f each component of the batch.
- When t c he i oncreten p d st u ot roducedr i o c ue bo nexpectedp i easons n ne oncrete atching lant, t will be supplied from another plant located to place the concrete without interruption.
- The slump of concrete for piling shall be as the approved material during placing.
- T h e t e s t c y l i n d e r s s h a l l b e t a k e n f o r t h e c o n c r e t e o f e a c h p i l e a n d t h e r e l e v a n t t e s t s s h a l l b e done by the procedures as provided in the specifications in Site Laboratory.
TRAFFIC SAFETY CONTROL
Traffic Management Plan
T h e l a n e s s h a l l b e c l o s e d t o e x e c u t e , t r a f f i c w i l l b e m a i n t a i n e d a n d g u a r a n t e e d o n t h e D e t o u r road The Detour road shall be design based on the principles of facilitating the construction vehicles to enter or leave the site and the passing vehicles to pass smoothly.
Warning zone: 200m-long warning zone shall be set, in which the signs of "Speed Limit", "Operation A " head",O " No L vertaking",A " P Narrow ane head", No assing" shall b marked Te s heb pacea s etweens b l tdjacent3 u igns1 t hall e ess han 0m, sually 0m o
30m T last sign is at a distance of not lhe esst 1 hanf t f5m d rom( hes irst evice tapered ign) of the upper transition zone.
Buffer z : T he lone engtho b z f i 3uffer- 5 T oner s c 0 i t:- 0m he eflective one s ransited gradually to the traffic lane.
Operation z 0 l - one:0:- 5km-longo z s perationb s a a c one u hall e et s onstruction nit.
The tapered signs with interval of 2- 4m are placed on the sides of construction area.
Termination z T he l one:engtho t t f hez serminationn b l t oneT hall ot e ess han10m he sign of "Restored Traffic" shall be placed at the end of the termination zone.
The s pecialp s hallbersona e ppointeda t b a tf he e eginningo t c nd inishing nd f he losed sections to direct traffic with a red flag.
3 Traffic Control of Blocked Sections
F o r c o n s t r u c t i o n p e r s o n n e l i n a c c o r d a n c e w i t h t h e s a f e t y r e g u l a t i o n s f o r c o n s t r u c t i o n T h e reflective working clothes and safety helmets shall be worn
No drinking, slippers, and sandals are allowed on site.
The i nsurancef s b p eeo t halla w e f aid bn i ime f tndc arning lashlights e nstalled or he onstruction vehicles.
The t rafficr s bulesc p hallw a ne p om o t liedl o t ith a nd r o arking n he ane r urning round andomly be permitted for construction vehicles.
A full-time safetyman shall be arrangement to supervise the execution of the project.
S a f e t y s i g n s s h a l l b e p l a c e d i n b r i g h t e n v i r o n m e n t a n d a t a p r o p e r d i s t a n c e f r o m t h e d a n g e r location so that the relevant people have enough time to note the information that it represents.
T h e s a f e t y s i g n s w i t h d i s p l a c e m e n t s h a l l b e a d j u s t e d i n p l a c e t o a v o i d a c c i d e n t s , w h i c h r e s u l t from the relevant people's not quickly noticing and understanding the safety information.
ENVIROMENT AND SAFETY CONTROL
Safety Control
Prior to commencing any activity, a joint meeting should be conducted with relevant staff to provide a comprehensive overview of the work's scope, objectives, and implementation strategies to ensure efficient execution.
A l l w o r k e r s s h a l l a l w a y s w e a r P e r s o n a l P r o t e c t i v e E q u i p m e n t ( P P E ) , s u c h a s h a r d h a t (helmet), safety shoes, hand gloves and working uniform.
3 Prevention of Accident by Heavy Machine
O n l y s k i l l e d o p e r a t o r s h a l l b e a l l o w e d t o o p e r a t e e q u i p m e n t o n s i t e I n c a s e o f n e w o p e r a t o r s , a t e s t o f s k i l l s h a l l b e c o n d u c t e d f i r s t p r i o r t o h i s a c c e p t a n c e t o t h e j o b P r e v e n t i v e m a i n t e n a n c e c h e c k s h a l l b e d o n e r e g u l a r l y a t e q u i p m e n t w o r k i n g a t s i t e p r i o r t o f u l l o p e r a t i o n S t a b i l i t y o f w o r k i n g a r e a a n d f o u n d a t i o n o f e q u i p m e n t s h a l l b e c h e c k e d p a r t i c u l a r l y a t l o c a t i o n s o f outrigger and track pad of cranes.
4 Prevention of Accident of Electrocution
E l e c t r i c g e n e r a t i n g e q u i p m e n t s h a l l b e p r o p e r l y p r o t e c t e d a n d p r o p e r l y i n s t a l l e d w i t h e a r t h c o n n e c t i o n E l e c t r i c w i r e s s h a l l r e l a t e t o e l e c t r i c a l t a p e s t o p r e v e n t e l e c t r i c l e a k a g e O n l y s k i l l e d operator shall be allowed to operate equipment on site.
5 Prevention of Accident in Night Shift Works
E n o u g h l i g h t i n g s y s t e m s h a l l b e p r o v i d e d f o r n i g h t s h i f t w o r k s e s p e c i a l l y i n s t a l l e d a t working p latforms.I n a t sf ecessary,w a sll bhel urroundingu T p w orking rea hall e ighted p he eople ho work on the site must wear reflective jacket, if worked at night.
E x i s t i n g f a c i l i t i e s e s p e c i a l l y e x i s t i n g o v e r h e a d e l e c t r i c l i n e , w a t e r l i n e , t e l e c o m m u n i c a t i o n line and other important facilities at surrounding area shall be taken with care not to damage.
Environmental Control
Responsibility for surrounding environment during Substructure work and shall comply with the Condition of Contract on Protection of Environment
If any other problems occurred in the site, applicable counter measures or prevention action shall be considered immediately and executed as soon as possible.
T h e C o n t r a c t o r s h a l l b e r e s p o n s i b l e f o r i m p l e m e n t i n g a n d m a n a g i n g m i t i g a t i o n m e a s u r e s during the construction of the Works The recommended mitigation measures are presented below.
E x h a u s t e m i s s i o n s f r o m c o n s t r u c t i o n e q u i p m e n t s h a l l b e s t r i c t l y c o n t r o l l e d i n a c c o r d a n c e The Contractors are requested to use standard equipment.
Brushing and watering shall be used where required to control dust and the spraying of mud.
Stockpiles should be covered or kept damp to avoid windblown dust.
W h e r e c o n s t r u c t i o n i s c a r r i e d o u t i n o r n e a r r e s i d e n t i a l a r e a s , n o i s e b a r r i e r s o r o t h e r measures shall be used to mitigate the effects of noise from construction equipment and construction m e t h o d s G r o u p a c c o m m o d a t i o n f o r w o r k e r s w i l l b e c o n s i d e r e d a s a n e w r e s i d e n t i a l g r o u p a n d s h a l l therefore be located at least 250m from the Site.
Workers working near noise emission sources shall wear noise attenuators
T o e n s u r e t h e w a t e r q u a l i t y o f l o c a l w a t e r c o u r s e s , p o n d s , a n d l a k e s t h e C o n t r a c t o r s s h a l l comply with the following environmental protection measures Care shall be taken with fuels and oils.
+ No waste material of any kind shall be disposed of into local watercourses, ponds, or lakes
+ S tationaryc onstructione o a a quipment, w fficesa nd ccommodation, orkshops nd s t o r a g e a r e a s a n d o t h e r t e m p o r a r y f a c i l i t i e s s h a l l n o t b e l o c a t e d n e a r t o l o c a l w a t e r c o u r s e s, ponds, and lakes
+ Fuels and oils shall not be stored near local watercourses, ponds or lakes and shall be stored in areas located at least 200m away from such water features.
T h e C o n t r a c t o r s h a l l b e r e s p o n s i b l e f o r t h e m a n a g e m e n t o f w a s t e m a t e r i a l s a n d w a s t e i n general arising during construction of the Works Management shall include the control of wastes on s i t e a n d i n t e m p o r a r y o f f - s i t e a r e a s , m i t i g a t i o n m e a s u r e s t o m i n i m i z e w a s t e o r r e d r e s s a n y p r o b l e m s that a frise w roma astew t w ssociateda t c aith r he o worksm ndf he ollection nd emoval f aste aterials rom site and disposal to an approved disposal area
Waste materials shall be all materials designated as waste or as surplus material for disposal a s d e t a i l e d i n t h e s p e c i f i c a t i o n ; a l l w a s t e m a t e r i a l s i n c i d e n t a l t o t h e c o n s t r u c t i o n o f t h e w o r k s i n c l u d i n g b u t n o t l i m i t e d t o o i l s , f u e l s , u s e d f o r m w o r k , t e m p o r a r y c o n t a i n e r s a n d p a c k a g i n g , e x c e s s c o n c r e t e , a n d b i t u m i n o u s m a t e r i a l s , e t c a n d a l l w a s t e a r i s i n g f r o m t h e C o n t r a c t o r ’ s o f f i c e s a n d accommodation
T h e c o n t r a c t o r s h o u l d p r o p e r l y t r e a t h u m a n w a s t e s f r o m c o n s t r u c t i o n c a m p s , a c c o m m o d a t i o n , w o r k s h o p s , a n d o f f i c e s T o a v o i d c o n t a m i n a t i o n o f t h e s i t e t h e C o n t r a c t o r s h a l l i n s t a l l m o b i l e t o i l e t s a t t e m p o r a r y s i t e o f f i c e s a n d f i x e d c o n s t r u c t i o n l o c a t i o n s s u c h a s b r i d g e s i t e s Public rubbish bins should also be installed at the site office and temporary office locations.
A l l s o l i d w a s t e s s h a l l b e c o l l e c t e d , s o r t e d o u t a n d d i s p o s e d o f t o a p r o p e r l y d e s i g n a t e d disposal a P rea.t t s rioro c o het Ctart sf donstruction,t l o s he ontractor hall etermine he ocation f uitable disposal a a reas b t pprovedr l a y heT Celevant s s ocal a s uthorities.a t he ontractor hall ubmit ll uch reas o t h e E n g i n e e r f o r h i s a c c e p t a n c e t o g e t h e r w i t h c o p i e s o f a l l r e l e v a n t p e r m i t s a n d a p p r o v a l s b y s u c h local authorities.