成层土地基基础极限承载力的模型试验研究

Model Testing and Study of Ultimate Bearing Capacity of Foundations on Layered Soils

本文通过大量的室内模型试验对地基土体分层情况下基础的极限承载力进行了试验研究,得到成层土地基极限承载力的大小与持力层土体强度、厚度的变化规律;并且根据试验结果分别对港口工程和土木工程中常用的迈耶霍夫和汉纳的理论计算方法、汉森加权平均法、扩散角法以及魏锡克的理论计算方法这四种成层土地基极限承载力计算方法进行了验证。其结果表明对于成层土地基基础极限承载力的理论计算,由魏锡克和迈耶霍夫的理论所得的计算结果与试验测量值最接近。最后运用有限元的方法对成层土条件下地基土体的变形及位移情况进行了模拟计算进一步验证了魏锡克理论的合理性。

With a great number of laboratory model tests carried out to study the ultimate bearing capacity of foundations on layered soils,the law that the magnitude of the ultimate bearing capacity of foundations on layered soils varies with the strength and thickness of the bearing stratum has been obtained.The test results have been verified with the theoretical calculation method of Meyerhof and Hanna,Hansen's method of weighted mean,the method of dispersion angle for load distribution and Vesic's theoretical calculation method,which are the four methods commonly used in port and civil engineering for the theoretical calculation of the ultimate bearing capacity of foundations on layered soils.The results of the verifications demonstrated that,for the theoretical calculation of the ultimate bearing capacity of layered soils,the calculated results by Vesic's and Meyerhof's theories were the most approximate to the values measured during the model tests.The finite element method was finally used to analogically calculate the deformation and displacement of foundations on layered soils,the results of which have further proved the rationality of Vesic's theory.