基于原位试验成果的地基非线性沉降分析

提出了利用小尺寸载荷试验（PLT）及标准贯入试验（SPT）成果准确求解地基非线性沉降的新方法。首先利用压板载荷试验成果经过双曲线拟合，确定出某一土层地基土的修正切线模量；然后根据不同深度的SPT标贯击数按照线性相关关系，确定该土层不同深度各分层土的修正切线模量；最后依据分层总和法求解地基或基础的非线性沉降。该方法的特点是能进行加载至极限状态的全过程非线性沉降分析，而计算原理简单，计算参数全部来自现场原位测试，附加应力依据压板试验成果进行自动修正。分析广东某大型油罐地基及某高层建筑筏板基础的沉降结果表明，该方法计算结果准确可靠，能满足以沉降控制为目标的地基基础工程设计要求。

Analysis of nonlinear settlement of foundations based on in-situ tests

A new technique for calculating nonlinear settlement of foundations is proposed by using the data of plate loading test (PLT) and standard penetration test (SPT). Firstly, hyperbolic curve fitted out from the data of PLT and the correctional tangent modulus equation of soils is established. Secondly, the correctional tangent modulus equations of different stratified soils at different depths are determined using input soil parameters from SPT in accordance with the linear correlation. Finally, the total nonlinear settlement of a large foundation is calculated by using layerwise summation method with correctional tangent modulus and additional stresses. The results of settlement analysis of a foundation of an oil tank and a raft foundation of a tall structure in Guangdong Province show that this technique is able to calculate the entire nonlinear settlement from initiation to ultimate limit state with its simple principle, reliable parameters and accurate results, so as to achieve the objective of subsidence control for foundation engineering design with this method.