The study of pile capacity with time of jacked PHC pile based on quasi-distributed optical fiber sensing technology

• 1、School of Civil Engineering of Qingdao Technological University

Abstract：The change in pile capacity with time after installation is usually referred to time effect or set-up, which is particularly significant in saturated soft clay. Rearch shows that the time effect of bearing capacity of precast pile is mainly closely related to the parameters of pile length, section area, soil friction angle, the elastic modulus, the osmotic coefficient, the resting period and so on. It is meaningful to saving the cost and determining the final pressure legitimately considering the time effect influence to the pile foundation capacity adequately. The singular ultimate-bearing capacity can be confirmed when the completed piles are repressed at specified time by the convenient pile jacking machine, which is named as the method of interval re-pressed tests .This method is simple and the change of singular ultimate-bearing capacity can be shown at random time after installation which has the advantage of more flexible test point and lower cost comparing with static load test. We can observe the change of pressure through the interval re-pressed test of jacked pile with FBG sensors. Through that it is useful to analyze the change of basis resistance and shaft resistance during the rest time which has significant engineering reference value.

Keywords： time effect of bearing capacity interval re-pressed test FBG sensor the singular ultimate-bearing capacity shaft resistance