不同理论公式预测粘性土地基极限承载力比较

Comparison of ultimate bearing capacity prediction for cohesive soil foundation with 3 theoretical formulas

基于文献中实测的载荷试验数据和计算数据,采用有限元软件ABAQUS建立三维模型进行计算分析,对Vesic、Hansen和Meyerhof三个理论公式预测粘性土地基极限承载力进行了比较,讨论了基础尺寸、基础埋深、土性参数等因素对预测结果的影响。结果表明:(1)这三个公式预测粘性土浅基础(D<B)极限承载力误差相对较小,但均不适用于粘性土深基础(D>B)。(2)对于粘性土浅基础,三个公式预测值总体上均偏大,一般Meyerhof公式误差最大,Vesic公式误差最小;当φ<25°、粘聚力c<20 k Pa时,各公式预测误差一般不超过10%;各公式预测误差随地基土内摩擦角和粘聚力增大而增大。

Based on the cited data of loading tests and calculation, 3-D finite element analysis is con-ducted with the software ABAQUS. Comparison of 3 theoretical prediction formulas for ultimate bearingcapacity is carried out, which are Vesic＇s, Hansen＇s and Meyerhof＇s. This paper discusses the impact onprediction results of foundation size, foundation embedded depth and soil properties. The results showthat：（1） The prediction errors of these three formulas are relatively low when they are used for shallowfoundation（DB） of cohesive soils. However, none of these three formulas is applicable for deep founda-tion（DB） of cohesive soils.（2） For shallow foundation of cohesive soils, the ultimate bearing capacity istotally overestimated with these three formulas. In general, prediction result of Meyerhof＇s formula islargest, and Vesic＇s is closest; when the soils＇ properties meet the condition of φ25° and c20 k Pa, theprediction errors of these formulas are no more than 10% generally; the prediction errors of these formu-las increase with the increasing of the frictional angle and cohesion of foundation soils.