倾斜荷载作用下的地基临界荷载

Critical load of ground under inclined load

结合半平面体边界受集中荷载下的弹性应力解与Mohr-Coulomb强度准则,推导了倾斜荷载作用下地基临界荷载p1/4的数值计算公式。绘制倾斜荷载作用下的塑性边界线和地基附加应力等值线,研究发现,倾斜荷载下基底附加应力非对称分布,σsz受荷载发生倾斜的影响相对较小,而σsx和τsxz受其影响很大,进而影响地基中塑性区发育。临界荷载p1/4随荷载倾角的增大而减小,单一变量法结果显示:减小速率与土体黏聚力c、土体内摩擦角φ及荷载倾角α有关,与基础埋深d无关;黏聚力c和内摩擦角φ越小,倾角α越大,则影响越小。

Combining with the elastic stress solution of Semi-plane bearing concentrated force on the border and Mohr-Coulomb strength criterion,the numerical formula of critical load p1/4 was deduced in inclined load.Plastic boundary and additional stress contours were plotted.Asymmetric distribution of additional stress in ground under inclined load was testified,which had tiny influence onσsz but huge influence onσsx andτsxz,and further affected on the development of plastic zone under inclined load.Critical load p1/4 gradually decreased with the increase of load inclination angle.The results of single variable method show that the reduction rate is related to soil cohesion c,internal friction angleφof soil and load inclinationα,but not to the buried depth d of ground.The smaller the cohesion c and internal friction angleφof soil,the larger the inclinationα,the smaller the influence will be.