Soil/Pile Set-up Effects on Driven Pile in Malaysian Soil

摘要

Bearing capacity of a driven pile often increases with time after its installation. This phenomenon is well known as soil/pile set-up. Although the phenomenon is common and has been reported by many researchers, the increase capacity of pile with time is not always considered in pile design. This is mainly due to lack of understanding about the mechanism behind how principal factors such as soil type, pile material and its installation method affect soil/pile set-up. Pile testing such as maintained load test (mlt) or dynamic pile testing (dpt) is only conducted only after some time after installation. This raises some questions on the rate of pile capacity increase and the length of time after which soil/pile set-up effect becomes insignificant. Although in reality, the capacity increase of pile depends on various factors, the duration of full set-up is assumed to be dependent solely on soil type and rule-of-thumb judgment of the engineer at site is normally practiced. Consideration of the above factors has lead to this study, which has been carried out to investigate the soil/pile set-up as happened in Malaysian soil. Six case studies on soil/pile set-up in Malaysian soil conditions are presented. Pile capacities obtained from tests carried out at different elapsed time after installation are compared in order to further understand the effects of soil/pile set-up on driven pile capacities. Soil/pile set-up factor is back-calculated to understand its effects on Malaysian soil. Time effects on ratio of pile capacity at time, t over initial pile capacity (qt/q-initial) is also discussed at the end of this paper.