基于三剪应力统一强度理论的硬壳层软土地基承载力公式  

Formulas for bearing capacity of soft soil foundations with hard crust based on three-shear stress unified strength theory

作　　者：高江平[1] 刘雯支 杨继强 GAO Jiang-ping;LIU Wen-zhi;YANG Ji-qiang(Key Laboratory for Special Area Highway Engineering,Ministery of Education,Chang'an University,Xi'an 710064,China)

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室

出　　处：《岩土工程学报》2019年第12期2331-2337,共7页Chinese Journal of Geotechnical Engineering

摘　　要：硬壳层软土地基与均质地基不同,由于其封闭作用和扩散作用,其地基临塑荷载和临界荷载与均质地基的有较大差异,将三剪统一强度理论运用到双层地基分析计算中,并考虑静止侧压力系数不为1的情况,以及硬壳层应力扩散作用和封闭作用对地基的影响,得出硬壳层软土地基的临塑荷载和临界荷载计算公式,同时,通过系数b,c的变化,得出双剪统一强度理论和莫尔–库仑理论下的地基承载力公式,并将3种计算公式通过实例进行比较。结果表明,随着参数b,c以及静止土压力系数的增加,地基承载力均会增加,同时双剪统一强度理论解以及Mohr–Coulomb解均为三剪统一强度理论解的特例,三剪应力统一理论解更符合工程实际情况。The soft soil foundations with dry crust are different from the homogeneous foundations. Due to the closure effect and stress diffusion of hard crust, the method for the plastic and critical loads of soft soil foundations is different from that for the homogeneous foundation. By using the unified strength theory of three shears to analyze and calculate the double-layer foundation and considering the influences of the closure effect and stress dispersion with the static lateral pressure coefficient, the formulas for the plastic and critical loads of hard-shell layer soft soil foundations are obtained. Meanwhile, by adjusting the coefficients b and c, the formulas for the bearing capacity of foundations under the unified strength theories of twin-shear and Mohr-Coulomb are obtained, and the three formulas are compared through examples. The results show that with the increase of the coefficients b, c and the static earth pressure, the bearing capacity of the foundation increases. The unified strength solution of twin-shear and Mohr-Coulomb solutions are divided into three shear unified strength solutions. The three-shear strength solution is more in line with the actual situation.

关 键 词：硬壳层软土地基 三剪应力统一强度理论 临塑荷载 临界荷载 

分 类 号：TU470[建筑科学—结构工程]