Pile Driving

Following data should be recorded when pile is being driven:

1 ) Diameter of the pile. 

2)  Depth driven. 

3)  Sequence of driving in a pile group. 

4)  Set for last ten blows or as specified. 

5)  The type and size of the hammer and its stroke. In the case of double acting hammer, the number of blows per minute and stroke. 

6)  Type and condition of the packing on the pile head and of the dolly in the helmet. 

7) In case of driven cast in situ pile in variable ground, a record of driving resistance should be recorded.  

8)  In case of bored pile the boring log should be recorded. 

9)  In case bentonite slurry is used during driving, the record of density of slurry should be kept. 

Piles foundation should be driven either vertically or in specified inclination as accurately as possible. Any deviation should be reported to the designer for checking and redesigning. Generally the deviation for the pile should not be greater than 7.5 cm at the bottom of the pile cap and inclination of pile should not deviate more than 2% (or  10 from the specified inclination. 

Specified sequence of driving should he followed in case of group piles. For very soft soils piling should proceed from outside to inside and vice versa in case of stiff clay. 

Tell-tale mark of sinkage of ground as well as rising of piles should be carefully noted. In case of bored piles soil statum at bottom shall be checked by split spoon sampler or any other method. Before concreting collase of sides shall be checked. 

Initial load test shall be carried out on test piles usually at least on two piles. Routine tests as specified, usually 196, should be carried on working piles to assess settlement corresponding to working load. Lateral load test is also required for inclined or raker piles.