土钉支护加固机理的数值分析  

Numerical Analysis of the Reinforcement Mechanism of Soil-Nailing Support

作　　者：贺若兰[1] 张平[2] 李宁[3] 

机构地区：[1]中南大学土木建筑学院 [2]湖南大学土木工程学院,湖南长沙410082 [3]西安理工大学岩土工程研究所,陕西西安710048

出　　处：《湖南大学学报（自然科学版）》2007年第1期14-18,共5页Journal of Hunan University:Natural Sciences

基　　金：湖南省自然科学基金资助项目(06JJ3026)

摘　　要：采用摩擦-接触型界面单元模拟钉土界面真实的变形协调情况,建立了基坑开挖土钉支护的数值分析模型,并通过和工程实测对比验证了模型的可靠性.借助动态仿真分析支护系统内力、钉土界面剪应力以及土体应力状态和应力路径随开挖、支护的不断推进而发展变化的全过程,定量揭示了支护系统的加固机理:单根土钉发挥应力分担、扩散以及传递的锚固作用,分别改善土钉头部、中部和尾部土体的应力状态,并提高土体抗剪强度;群钉系统发挥整体加固作用,增加土体刚度;土体强度、刚度增加且应力减小,双重抑制了边坡位移和塑性区的发展.By using a friction-contacting interface element which can simulate the interface＇ s actual distortions such as closure, opening and slippage, a finite element model for the soil-nailing system was built, and its reliability and precision were validated by comparison with field measurements. With the development of the supporting system＇ s inner force, interface＇ s shear stress and the stress state of a point in the soil, the reinforcement mechanism of the supporting system was quantitatively revealed as follows： single nail played an anchoring role such as stress sharing, stress dispersion and stress passage, and group nails played a reinforcing role, which improved the soil＇s stress state, and simultaneously increased its shear strength and rigidity, then greatly decreased the displacement and plastic region.

关 键 词：土钉支护 数值分析 应力路径 加固机理 

分 类 号：TD824.72[矿业工程—煤矿开采]