考虑墙体位移与土压力耦合的弹性地基梁法

Elastic Foundation Beam Method Considering Coupling between Deformation Behavior of Retaining Wall and Earth Pressure

引入墙土摩擦角和土体内摩擦角发展规律的公式,建立非极限土压力与围护结构水平位移的耦合关系。并将该土压力模型嵌入弹性地基梁法的控制方程,利用杆系有限元法求解开挖全过程地下连续墙的受力变形特性。算法经应用于实际基坑案例,并与传统弹性地基梁法计算结果及现场实测数据对比分析,结果表明:考虑围护墙位移与土压力耦合关系的弹性地基梁法能够合理计算及反映土压力从静止土压力向主动土压力的发展过程;对比传统弹性地基梁法,该修正方法计算的围护结构的受力变形特性计算值与实测值更吻合,可为工程实践与设计优化提供更好的理论支持。

Deriving the formula which reflects the law of the development of the friction angle of the soil-wall interface and internal friction angle, the coupling relationship between earth pressure and horizontal displacements of retaining walls is built. By taking this soil pressure model as a governing equation in elastic foundation beam method, the finite element method is used to calculate the stress and deformations of underground diaphragm walls during the whole excavation. This proposed method is applied to analyze a real excavation project case, and the calculation results are analyzed by contrasting with the results of traditional elastic foundation beam method and field data. The results show that the improved method which considers the interaction between earth pressure and displacements of retaining walls can represent the development process of earth pressure from resting state to limit state and get earth pressure values. Compared with traditional elastic foundation beam method, the results of horizontal displacements and bending moments are closed to those measured values, which can provide great support for engineering practice and design optimization.