由单桩载荷试验预测桩筏基础沉降的简化分析方法

Approximative analysis for piled rafts by pile load tests

在桩筏基础设计中,单桩载荷试验结果通常只用于确定桩的承载力,而很少用于群桩沉降分析中。本文通过载荷试验初始刚度反分析地基的弹性参数,同时将桩假定为相互作用的非线性弹簧,使用双曲线函数拟和载荷试验数据,并用它来模拟桩–土界面的非线性关系。使用相互作用系数的方法分析桩–桩之间的相互作用,同时考虑桩的“加筋”对土的位移场的影响。经过实例分析比较,该方法不但可以大量节省计算时间,而且计算结果与实测数据相比也比较满意。

Pile load tests are usually carded out for determining the ultimate bearing capacity, but not for predicting the settlement of piled raft. The elastic parameters of the subsoil were achieved through the initial stiffness of the pile load tests. Piles were modeled as interacting nonlinear springs. The nonlinear behaviour of pile-soil interaction could be matched by the hyperbola function. The interaction between piles was analyzed with interaction factors, and＂restraint＂action between piles was considered. Compared with theoretical and experimental results, this approximate method could save a large amount of computing time and give reasonable results.