环形沉井刃脚踏面基础地基极限承载力分析

Analysis of Ultimate Bearing Capacity of Ring Cutting Curb of Open Caisson Foundation Tread

讨论了沉井下沉时刃脚踏面下土体的滑移方向,并以此为基础,基于Mohr-Coulomb准则,利用更有利迭代收敛的有限差分公式将滑移线理论的α,β两族滑移线方程进行差分并建立刃脚踏面承载力数值计算模型;再根据刃脚踏面边界条件,利用Matlab软件编制计算程序对下沉过程中环形沉井刃脚踏面基础的地基极限承载力进行了分析,得出了环形沉井刃脚踏面土压力分布特性和变化规律;同时对不同条件下的极限承载力进行分析。又结合工程实例,把该理论计算结果和现场实测结果进行对比分析,验证计算结果的合理性。

This paper discussed the soil mobility trends under the cutting curb which flow to medial during open caisson sinking. Based on the Mohr-Coulomb principle, the finite difference method was applied to discrete the α and β family characteristics equation deduced from the slip line theory, authors obtained the difference formula in the axisymmetric limiting equilibrium condition and established the bearing capacity numerical model of cutting curb. According to the tread cutting curb boundary conditions, authors adopted Matlab software to analyze the ground ultimate bearing capacity and obtained the tread soil pressure distribution characteristics and change law of ring cutting curb foundation. At the same time, they analyzed the ultimate bearing capacity in different influencing factors. The tread ground ultimate bearing capacity and the measured results were compared.