3 EQUIPMENT SIMPLE/ SOPHISTICATED SIMPLE/ SOPHISTICATED SIMPLE/ SOPHISTICATED
124 125 List of reference codes
IS 2911 part -1 (sec 1) - Design & construction of pile foundation ¾
(DCIS)
IS 2911 part -1 (sec 2) - Design & construction of pile foundation ¾
(BCIS)
IS 2911 part -1 (sec 3) - design & construction of pile foundation ¾
(Driven precast))
IS 2911 part-4 –Load test on piles. ¾
IS 14593 –Design & construction of bored cast-in-situ piles founded ¾
on rocks.
IS 14893 – Non destructive integrity testing of piles ¾
BS-8004 –1996 code of practice for foundations ¾
ASTM d 5882 -07 – standard test method for low strain impact integrity ¾
testing of deep foundations
ASTM d 4945 – 00 - standard test method for high-strain dynamic ¾
126 127 INSTALLATION SEQUENCES - DRIVEN CAST-IN-SITU PILES.
126 127
128 129 CONCRETING OPERATION IN A BCIS PILE.
128 129
130 131 IMPORTANT THINGS TO BE FOLLOWED
DRIVEN CAST-IN-SITU PILES
Plan movement of rig with respect to group of piles, Based on Priority of the Structure.
Cross check the location of piles with reference points.(Survey)
Check the pile shoe for stiffener welding. Ensure full welding is done instead of tack weld.
Place the pile shoe in the survey locations by excavating 200mm soil and place sand bags above the pile shoe after checking the Point.
Apply Bitumen in the annular space between the casing and pile shoe to avoid water ingress.
Check for verticality of casing during driving and Monitor frequently & Record.
Maintain Height of Fall as per set Calculation .Record the No.of blows and record as per the Format.
Terminate the pile based on set criteria.
Check for water ingress inside the casing before concreting using water level indicator(make AIMIL)
Check for proper welding of rebar lap joints. Maintain proper cover.
Lower the Reinforcement carefully and hold the reinforcement and monitor the same during Extraction.
Keep the concrete slump between 100mm to 150 mm.
Proper care during withdrawal of casing. (The energy required for withdrawal should be half of driving. This will ensure proper compaction of concrete inside.)
The concrete pressure > overburden pressure always during extraction of casing.
Check for Theoretical Vs Actual concrete consumption for each pile. Check the Top of concrete after extraction from NGL
130 131
Maintain a gap of “6d” between construction of successive piles.(where “d “= diameter of pile )
Piling sequence is to be followed.
Pile Driving shall normally be from the center to periphery or from one side to other of a pile group.
Backfill the Empty bore (unconcreted portion above COL) of the pile with sand or with approved materials.
BORED CAST IN-SITU PILES
Fix the pile point &Cross check the location of piles with reference points.
Drive the Temporary casing vertically in Location.
Fill the Bentonite slurry inside the bore. Always maintain the head of Bentonite slurry 2M above Water table.
Check for verticality during drilling continuously and Record. Collect the soil sample from the bore and record.
Check for bentonite slurry quality regularlyby testing the same for flow, specific gravity and density during drilling and after flushing and record.
Check the length of drilling by sounding using chain links.
Terminate the pile as per Drawing. If specified by client, terminate the pile based on SPT.
If socketing in Rock, Terminate the same as per Drawing. Clean the bore thoroughly before inserting Reinforcement.
Insert reinforcementcage. If length of pile is more, ensure proper splice welding is done on reinforcement cage while insertion.
Check for Tremie pipes cleanliness & threading arrangement before concreting.
Lower the Tremie and continue flushing with fresh bentonitetill we get bentonite slurry specific gravity equivalent to fresh slurry.
132 133 Insert Tremie pipe to the required length leaving a gap of 100mm from
pile toe level and Record.
Tremie pipe diameter should be >200 mm for concrete mix having 20mm size aggregates.
Check the Capacity of Concrete Hopper.
Start concrete operation after flushing and after checking the specific gravity of slurry.
Keep the concrete slump between 150mm and 180 mm. Grade of concrete as per approved Mix Design.
Tremie pipe should be always 2 to 3 m inside the concrete during concreting operation
While removal of Tremie shake the same to ensure proper compaction of concrete , ensuring that the Tremie pipe does not leave the concrete surface
Maintain the Record of Tremie Removal during operation.
The concrete pressure > overburden pressure always during concreting with Tremie.
All concrete operation should be completed within six hours.
Backfill the Empty bore if any(unconcreted top portion, i.e., from COLto EGL) of the pile with sand or with approved materials.
Muck shall be disposed at designated area/dump yard. DRIVEN PRECAST PILES
Prepare a neat leveled casting bed free from undulations. Check the alignment during and after casting the piles. The pile shoe should be properly aligned during casting. Lifting hooks should be properly positioned.
Ensure concrete has flown inside and well compacted near pile shoe and end points.
Use Concrete(grade as specified in GFC drawing) with a slump of 80 to 130mm for casting
132 133
Check whether the precast piles have attained the required strength before lifting it.
Lift the pile with Lifting arrangements (Strand back) Cross check the location of piles with reference points. Check for verticality during driving.
Take extra precaution for splice joints.
Pile driving sequence should be properly followed. Pile driving shall be from Centre towards outside or from one end to other end in a pile group.
Use stress band at the top of the pile during pile driving.
If the precast pile length exceeds 22m length, then joints are required
PRECAST PILES JOINTS:
134 135 LOAD TEST ON PILES
Vertical Load Test:
Intial Load Test Routine Load Test
Test load = 2.5 times of design load or upto failure whichever is earlier.
Test load = 1.5 times of design load or 12mm whichever is earlier
Load test will be carried on Initial test piles seperately casted especially during beginning of project.
Load test will be conducted on working piles. The quantity will be generally 1.5% to 2% of total number of piles.
Type of Arrangements:
Kentledge Method (Placing of Concrete blocks or Sandbags over platform) Anchor Method By Rock anchors. ¾ By Anchor piles. ¾
134 135 VERTICAL LOAD TEST ARRANGEMENTS:
136 137 Arrangement for Vertical Load Test
136 137 LATERAL LOAD TESTS ARRANGEMENTS:
138 139 PULLOUT (OR) UPLIFT TEST ARRANGEMENTS:
Lateral Load Test Photograph PULLOUT (OR) UPLIFT TEST ARRANGEMENTS:
138 139
140 141 PILE INTEGRITY TEST:
This test evaluates the pile integrity and pile physical dimensions (that is, cross-sectional area, length), continuity, and consistency of the pile material, although evaluation is approximate and not exact. This test method will not give information regarding the pile bearing capacity.
PDA TEST (HIGH STRAIN DYNAMIC TEST):
This test method is used to provide data on strain or force and acceleration, velocity or displacement of a pile under impact force. The data are used to estimate the bearing capacity and the integrity of the pile, as well as hammer performance, pile stresses, and soil dynamics characteristics, such as soil damping coefficients and quake values.
Good Pile
140 141