条形基础下临坡地基极限承载力影响因素数值模拟分析

Numerical simulation of factors affecting the ultimate bearing capacity for strip foundations adjacent to slopes

按平面应变问题建立有限元数值模型,通过比较有限元解与极限平衡解,检验该数值模拟的计算精度。基于数值模拟计算结果,分析了地基土强度、边坡角、坡顶距、基底接触条件等因素对临坡地基极限承载力的影响。针对纯黏土,提出临界强度、过渡点的概念,建立了临坡地基土体强度与地基破坏模式的定量对应关系。得出边坡角越小,地基土内摩擦角对于临坡地基极限承载力的影响越明显;边坡角越大,临坡地基极限承载力随坡顶距的增长速度越快;纯黏土的qu/(γB)-c/(γB)曲线由曲线段及直线段构成,分别对应地基整体失稳和局部失稳破坏。

Finite element numerical model was developed for plane strain problems. The calculation accuracy of the numerical simu-lation was evaluated by comparing the finite element solution with the limit equilibrium solution Based on the numerical simula-tion results？ the influence of factors such as soil strength, angle of slope, distance from the edge of slope, roughness of founda-tion base on the ultimate bearing capacity of foundations adjacent to slopes was systematically analyzed. For pure clay, the con-cept of ^ transition pointand “ critical intensity” were introduced. The quantitative corresponding relationship between soil strength and failure modes for foundations adjacent to slopes was established. It was found that the smaller the angle of slope, the more obvious is the impact of the internal friction angle on the ultimate bearing capacity of foundations. The greater the angle of slope, the faster is the growth of the ultimate bearing capacity with the distance from the edge of slope; For pure clay, qu/yB-c/（yB） curve consists of curved segments and straight line segments？ which is corresponding to foundation overall collapse and local collapse, respectively.