基坑土钉支护安全系数的强度参数折减有限元方法

针对基坑土钉支护讨论其安全系数的强度参数折减有限元计算方法,包括土钉支护体系的三维有限元模型、安全系数的折减强度参数计算、极限状态的确定以及极限状态下的计算方法等。按所建议方法,编制了三维有限元计算程序,并给出算例,展示了所建议计算模型和方法的有效可靠性。此外,还对有限元方法计算的安全系数与现行土钉支护规程建议公式所计算安全系系数的可比性进行了讨论。

Finite element calculation for safety factor of soil nailing through reduction of strength parameters

In connection with soil nailing support for deep excavations, the calculation of safety factor by finite elements based on the concept of reduction of strength parameters is discussed, including the three dimensional finite element models for soil nailing, the colculation of safety factor through reduction of strength parameters, the identification of limit state and calculation techniques for limit state analysis. A computer program is developed based on the proposed computation model, and numerical examples are given to show the reliability and effectiveness of the model. Moreover, the comparability between the safety factor calculated by FEM and that by the formula in the current design code is also discussed.