(中国地质大学(北京)工程技术学院北京 100083)

［提要］结合深基坑土钉墙支护工程实例，应用国际通用的有限差分分析软件—FLAC 3D程序，分析了基坑分步开挖与支护的受力、变形模式，模拟了土-土钉-面层协调作用的支护效果。数值模拟结果表明，随着基坑开挖深度的增加和支护体系的不断实施，支护体受力也逐渐下移，基坑开挖结束后受力主要集中在沿基坑深度的中间部位，同时土钉受力均以轴向拉力为主且远小于其抗拉屈服强度，说明支护设计是偏于保守的。将模拟结果与支护实测数据对比，二者基本吻合，说明合理运用数值分析方法可为工程优化设计提供科学依据。

［关键词］土钉墙  三维数值分析  有限差分法

3D Numerical Analysis on Deep Foundation Pit Support Engineering in Shijiazhuang Yuyuan Mansion/Yang Shengbin(School of Engineering & Technology, China University of Geosciences, Beijing 100083, China)

Abstract:Based on an engineering project, the finite difference method, FLAC 3D program is used to analyze the mechanic process and the deformation mode of the pit support engineering, and to model the cooperative function of soil-nail-surface. The numerical analysis results show that the force of soilnailing moves down with the excavation depth increasing, the half depth of the pit is the main working area at the end of excavation, and the design is conservative because the axial force of soil nailing is far less than its ultimate tensile strength. Meanwhile, the numerical analysis results including the pit displacement and the mechanics of soil nailing are matched with the measured data on the whole, which can provide scientific reference to optimize the design of similar engineering.

Keywords:soil nailing wall; 3D numerical analysis; finite difference method