BORED PILING: Civil & Structural Piling Specifications Part 2- Performance Requirement

2.         PERFORMANCE REQUIREMENTS

2.1       Requirements for Design Verification

The required working load and sizes of the piles are indicated in the drawings, together with an indication of the required pile penetration depth.

Based on actual ground conditions encountered as revealed by boring logs or ground investigations, carry out design check to confirm the required pile length as to achieve the specified  working  load  within  the  specified  limits  for  load  settlement  behaviour  as indicated in Clause 2.2. Account for effects of negative skin friction where applicable.

Verify the design based on SS CP 4 unless otherwise agreed.

2.2      Performance Criteria for Bored Piles

Any of the piles, when under static or dynamic load test, is to satisfy the performance criteria as set out below:

Axial Compression Tests (Ultimate and Working Load)

Pile Type and Size	Specified Working Load (Axial Compression)	Permitted Settlements (mm)
	(SWL) (kN)	1.0*SWL (2nd cycle)	1.5*SWL (2nd cycle)	2.0*SWL (2nd cycle)	Residual Settlement (End of 2nd cycle)
900mm diameter Bored Pile 1200mm diameter Bored Pile	4550 8500	7 7	15 15	25 25	7 7

In addition, the overall pile capacity in ultimate load tests is to have factors of safety of at least 2.5 against design ultimate compression load, 2.0 against design ultimate lateral load and 3.0 against design ultimate tension load.

2.3      Permissible Damage Criteria for Existing Critical Structure or Services

Based on the results of the damage assessment as set out in Clause 1.4.2, propose the allowable ground settlement and vibration limits due to the works taking into account the vulnerability  and  sensitivity  of  the  adjacent  properties  e.g.  VLCC  (48”  Crude  Oil Pipelines).

State the values for alert and work suspension levels in the submission in accordance with the requirements of Building Control Act [Section 7(2)] Annex (BE/CP/5).

Notwithstanding the above, ensure that the ground movements and vibrations generated by the works comply with the following if more stringent:

NPQS

                                                                                                                                                                             C4-10 Bored Piling Piles

a.        Generally comply with the requirements of BS 5228 Part 1.

b.        The vibration generated by the works in MRT structures not to exceed a peak particle velocity of 15mm/s.

c.        Unless otherwise directed, refer to Section C2-50, Clause 4.2.2 for general restrictions on ground movements and vibration limits for adjacent structures where relevant.

d.        Refer to piling drawings for vibration limits.