考虑天然黏土应力各向异性的静压沉桩效应研究

 基于K0固结各向异性修正剑桥模型(K0-MCC)，考虑天然饱和黏土的初始应力各向异性及应力诱发各向异性特征，推导天然饱和黏土地基中静压沉桩扩孔问题的理论解，提出沉桩阻力的理论计算方法。在此基础上，通过静压沉桩离心机模型试验，对理论解进行验证，研究静压沉桩过程中桩周土压力、孔压及沉桩阻力的变化规律。结果表明，由于提出的理论解合理考虑了天然黏土地基的固有特性，因而可以较好地反映天然饱和黏土中的静压沉桩效应。研究成果为静压桩施工及承载力确定提供了理论依据，具有一定的理论和工程意义。

Pile jacking-in effects considering stress anisotropy of natural clay#br#

The Cam-clay model modified for the K0-consolidated anisotropic clay，which can properly describe the initial stress anisotropy and stress-induced anisotropy of the natural saturated clay，was used to derive a theoretical solution to the cavity expansion due to pile jacking-in. The method of calculating the resistance of pile sinking is presented. To verify the validity of the theoretical solution，a centrifuge test of pile jacking-in was carried out in K0 consolidated clay. The soil stress，pore water pressure and pile-sinking resistance were studied in detail by comparing the measured data with the predicted data. The results show that the proposed mechanical model reflects the pile jacking-in effects properly due to the intrinsic properties of the natural clay being sufficiently considered. The proposed solution provides a theoretical base for pile construction and bearing capacity determination.