软土深基坑钢支撑预加力对围护结构变形影响数值分析

Numerical Analysis of the Influence of Soft Soil Deep Foundation Pit Steel Support on the Deformation of the Envelope Structure

为提高软土深基坑钢支撑预加力对围护结构变形影响分析的准确性,设计软土深基坑钢支撑预加力对围护结构变形的合理影响数值分析方法。以实际工程为例,根据该工程中岩土物理力学参数,设定计算模型的基本假设条件、边界条件及施工阶段的条件;采用基于支持向量机(SVM)的最小二乘算法和核函数分析技术设计数值分析方案,建立计算模型。结果表明,当钢支撑预应力增加时,深层水平位移值减少;排桩在开挖后,位移最大值18.3 m出现在顶部,随着进一步开挖,位移曲线呈弓形变化;第一层钢支撑轴力变化最大,为800 kN;不同预加轴力下灌注桩最大位移值差异为10 mm;研究提出的分析方法与实际值相差小于10 m,有效提高了分析的准确性,满足设计需求。

In order to improve the accuracy of the impact analysis of soft soil deep foundation pit steel support on envelope deformation,the reasonable numerical analysis method of soft soil deep foundation pit steel support on envelope deformation is designed.Taking the actual project as an example,the basic assumptions,boundary conditions and construction conditions of the calculation model,and the least squares algorithm based on SVM and nuclear function analysis are used to establish the calculation model.The analysis results show that when the prestress of the steel support increases,the deep horizontal displacement value decreases.After the excavation,the maximum displacement 18.3 m appears at the top and the displacement curve changes arch.The axial force of the first layer is 800 kN;the maximum displacement value under different pre-axial forces is 10 mm.The experimental results show that the studied analysis method is less than 10 m,which effectively improves the analysis accuracy and meets the design requirements.