cmorgh
Geotechnical
- Dec 17, 2002
- 35
Hi,
Some test piles have been statically tested both axially and laterally.
About Axial Loading Test:
The final settlement for the most of the axial loading tests exceeded 30 mm. At this stage, the settlement criteria for the piles have yet to be specified, however for two different areas the maximum allowable settlements are expected to be 1 cm and 2.5 cm, respectively.
About Lateral Loading Test:
There exists a very soft to soft clay layer about 20 m in depth, beneath which there is a very dense sand layer (N>50). Pile tip is driven into the sand layer.
The maximum lateral imposed load is 10 metric tons and the maximum lateral displacement is about 5 cm. The pile is a precast-driven concrete pile, 40 cm x 40 cm in cross section.
The loading and unloading curves do not show any probable broken behavior, whilst the proportions of the plastic and elastic settlements based on the analysis of the test curve are 65% and 35%, respectively.
My questions are as follows:
1- If the excessive settlement is observed (as in here), could it really be helpful to discuss about the analysis of the ultimate bearing capacity values obtained by some general methods such as Chin’s, Brinch Hanson’s 90% criteria, Tangent methods, etc? Whilst for all piles, the settlement criteria leads to a lesser ultimate bearing capacity in comparison with other methods.
2- As far as I know, there is not any comprehensive method of ultimate bearing capacity analysis for the static lateral loading test. I appreciate it to receive some comments regarding the judgment about allowable lateral load (disregarding any structural limitations for lateral displacement and without any computerized analysis of the test pile by say spring stiffness factors which simulate the interaction of soil and pile).
Regards
and
Thanks for your comments
Some test piles have been statically tested both axially and laterally.
About Axial Loading Test:
The final settlement for the most of the axial loading tests exceeded 30 mm. At this stage, the settlement criteria for the piles have yet to be specified, however for two different areas the maximum allowable settlements are expected to be 1 cm and 2.5 cm, respectively.
About Lateral Loading Test:
There exists a very soft to soft clay layer about 20 m in depth, beneath which there is a very dense sand layer (N>50). Pile tip is driven into the sand layer.
The maximum lateral imposed load is 10 metric tons and the maximum lateral displacement is about 5 cm. The pile is a precast-driven concrete pile, 40 cm x 40 cm in cross section.
The loading and unloading curves do not show any probable broken behavior, whilst the proportions of the plastic and elastic settlements based on the analysis of the test curve are 65% and 35%, respectively.
My questions are as follows:
1- If the excessive settlement is observed (as in here), could it really be helpful to discuss about the analysis of the ultimate bearing capacity values obtained by some general methods such as Chin’s, Brinch Hanson’s 90% criteria, Tangent methods, etc? Whilst for all piles, the settlement criteria leads to a lesser ultimate bearing capacity in comparison with other methods.
2- As far as I know, there is not any comprehensive method of ultimate bearing capacity analysis for the static lateral loading test. I appreciate it to receive some comments regarding the judgment about allowable lateral load (disregarding any structural limitations for lateral displacement and without any computerized analysis of the test pile by say spring stiffness factors which simulate the interaction of soil and pile).
Regards
and
Thanks for your comments
