基于正交设计和粗糙集理论的地基极限承载力影响因素分析

Factors Affecting the Ultimate Bearing Capacity of Foundation Based on Orthogonal Design and Rough Set Theory

基于滇中高原某大型工程的统计数据,利用ANSYS和FLAC3D建立了覆盖型岩溶发育区的典型溶洞模型,计算了岩石黏聚力和内摩擦角、抗拉强度、顶板厚度、高跨比、溶洞半径和基础宽度6种影响因素下的地基极限承载力,并总结其规律;利用正交分析和粗糙集理论,分析了这6种影响因素对地基极限承载力影响的大小。结果表明:顶板厚度和抗剪强度影响最大;溶洞半径、高跨比和基础宽度影响其次;顶板抗拉强度影响最小。

According to the statistical data of a large-scale project in Yunnan Plateau, a typical karst cave model covered with clay was established by employing ANSYS and FLAC3 D, and the ultimate bearing capacity of founda- tion was calculated and its regularities were summarized in the presence of varying cohesion, internal friction angle, tensile strength, thickness of roof, depth-span ratio, cave radius, and cave width. Furthermore, through orthogonal analysis and rough set theory, the influences of these factors on the ultimate bearing capacity of the foundation were analyzed. Results reveal that roof thickness and shear strength have the biggest influence on the ultimate bearing capacity, followed by cave radius, depth-span ratio and chve width, while tensile strength has the smallest impact.