交通荷载作用下软土地基累积塑性变形分析

针对交通荷载作用下软土地基的变形问题,采用累积应变的经验公式计算其累积沉降。首先通过确定车辆荷载引起的动偏应力和土层的力学指标计算出静力破坏偏应力,然后通过考虑土物理力学性质、循环荷载次数的累积变形公式计算软土地基中各土层在车辆荷载作用下引起的残余累积应变,最后用分层总和法计算总沉降。采用该方法对交通荷载作用下上海地区典型软土地基的累积沉降进行了实例分析。

Analysis of Cumulative Plastic Deformation of Soft Clay Foundation under Traffic Loading

Using an empirical cumulative plastic strain formula,a method for calculating the traffic load induced deformation was proposed.Firstly,according to the mechanical properties of soft clays and the traffic load induced dynamic deviator stress,the static failure deviator stress was determined.Secondly,the cumulative plastic strains of each soil layers were then calculated by the empirical equation in which the dynamic deviator stress,static failure deviator stress and number of repeated loading were considered.Finally,the total cumulative settlement of the subsoil was calculated with method of summation of sub-layers.A practical example for the traffic load induced deformation in Shanghai soft clays was presented.