论文部分内容阅读
分别以柱孔和球孔扩张模拟桩身和桩端的贯入过程,采用可以考虑天然饱和黏土应力历史和应力各向异性的圆孔扩张解答描述桩周土体的应力状态,推导了饱和黏土地基中静压桩终压力的理论解,进而基于桩周孔压径向消散的固结解答,在考虑桩周土再固结过程中松弛效应的基础上,推导了沉桩结束后静压桩时变承载力的解答,建立了静压桩承载力时效性系数的理论表达式。通过离心模型和现场试验对所提的理论解答的正确性进行了验证,研究了天然饱和黏土中静压桩承载力的时效性。结果表明:沉桩结束后较短时间内静压桩承载力时效性是超孔压消散和土体触变恢复共同作用的结果,一定间歇期后超孔压消散成为承载力增长的主要原因。
The penetration process of the pile body and the pile tip is simulated by the expansion of the column hole and the ball hole respectively. The stress state of the soil around the pile body is described by the solution of the circular hole expansion which can consider the stress history and stress anisotropy of the natural saturated clay, and the saturated clay foundation Based on the theoretical solution of the final pressure of the hydrostatic piles, and based on the consolidation solution of the pore pressure dissipation in the radial direction of the pile, based on the relaxation effect in the re-consolidation process of the piles around the soil, Change the bearing capacity of the solution, the static pressure pile bearing capacity of the time coefficient of the theoretical expression. The correctness of the theoretical solution proposed by the centrifugal model and the field test was verified, and the timeliness of the bearing capacity of the jacked piles in natural saturated clay was studied. The results show that the timeliness of bearing capacity of jacked piles in a short time after pile driving is the result of the combination of excess pore pressure dissipation and thixotropy restoration. The dissipation of excess pore pressure after a certain interval is the main reason for the increase of bearing capacity.