摘要
基于全长黏结式锚杆切应力分布的理论表达式,研究了锚固体与围岩界面的传力机制,提出了锚固体受力比的概念;结合实际工程,建立了单根锚杆基础的有限元模型,数值分析时模拟了界面的接触,理论解与有限元解吻合较好;基于此有限元模型,探讨了改善锚固体与围岩界面切应力分布的优化措施。分析结果表明:锚固体与围岩界面切应力沿锚固深度分布极不均匀,绝大部分都分布在锚固体前段,增大锚固体直径可有效改善锚固体与围岩界面切应力分布,当达到临界锚固深度时,继续增加锚固深度对提高锚杆基础承载力帮助不大。考虑到实际岩体存在风化的情况,提出了一种简单模拟岩层节理面的数值计算方法,结果表明考虑风化时,锚固体与围岩界面切应力峰值降低,切应力分布更加均匀。
Based on the shear stress distribution theory of fully grouted bolt,the force transfer mechanism of the interface between anchor solid and surrounding rock was studied,and the concept of anchor solid stresses ratio had been put forward in this article. Then,considering of contact interface,the finite element model of single bolt was also set up in the practical engineering. The finite element results agreed well with the theoretical ones. As well,based on this finite element model,the measures of improving the interface shear stress distribution between anchor solid and surrounding rock had been discussed. The analysis results showed that the distribution of interface shear stress between anchor solid and surrounding rock along the anchorage depth was extremely uneven,most were located in the front anchor,increase of anchor diameter can effectively improve this situation,continued to increase the anchorage depth were not help to improve the bearing capacity of the anchor foundation when reaching the critical anchorage depth. A simple numerical calculation method has been proposed to simulate the joint surface of rock strata with considering the different weathering degree of rock mass,the analysis results showed that considering the influences of weathering of rock foundation,the peak value of shear stress in the interface between anchor solid and surrounding rock were reduced and the shear stress distribution was more uniformity.
出处
《南昌大学学报（工科版）》
CAS
2016年第4期354-359,共6页
Journal of Nanchang University(Engineering & Technology)
基金
国家自然科学基金资助项目(11572147
51268043
51568046)
九江学院校级科研资助项目(8820109)
关键词
切应力分布
锚固体
受力比
有限元
风化
shear stress distribution
anchor solid
stress ratio
finite element
weathered
作者简介
张志平（1991-），男，硕士生；
通信作者：张雷（1986-），男，助教，博士生，164848990@qq．com。
