铁道标准设计2024，Vol.68Issue(6)：153-160,220,9.DOI:10.13238/j.issn.1004-2954.202210090001
考虑锚杆预应力作用下隧道围岩力学分析及参数设计
Mechanical Analysis and Parameter Design of Tunnel Surrounding Rock Considering Prestress of Bolt
摘要
Abstract
The design of anchor bolt in tunnel engineering mostly depends on empirical method and analogy method.In order to study the mechanical effect of surrounding rock in prestressed anchor bolt support system,a mechanical coupling model of prestressed anchor bolt and surrounding rock is established.Considering the damage effect of surrounding rock excavation,the analytical expressions of stress distribution and radial displacement of surrounding rock after tunnel excavation are derived by elastic-plastic mechanics theory.The finite difference software FLAC3D is used to verify and analyze the influence of prestressed anchor parameters on the state of surrounding rock.The results show that the maximum tangential stress and the radius of plastic zone of surrounding rock in theoretical analysis and numerical simulation are 4.77 MPa,15 m and 4.49 MPa,15.86 m respectively.The stress distribution and displacement of tunnel surrounding rock calculated by theoretical analysis and numerical simulation are basically the same.The rationality of theoretical analytical solution is verified in Ⅳ and Ⅴ grade surrounding rock strata.With the increase of pre-tightening force,the radial displacement of surrounding rock in plastic zone and the radius of plastic zone gradually decrease,while the elastic zone is basically unaffected.When the length of the free section of the bolt is located in the plastic zone,the radial displacement of the plastic zone and the radius of the plastic zone of the surrounding rock gradually decrease with the increase of the length of the bolt.In practical engineering,the pre-tightening force of bolt should be increased as much as possible.The increase of bolt length has limited control effect on the displacement of surrounding rock and the development of plastic zone.The length of free section of bolt should be controlled in plastic zone.关键词
隧道工程/预应力锚杆/力学分析/数值模拟/开挖损伤/参数设计Key words
tunnel engineering/prestressed anchor/mechanical analysis/numerical simulation/excavation damage/parameter design分类
交通工程引用本文复制引用
罗春雨,廖杭,余涛,李梦可,王飞阳,方勇..考虑锚杆预应力作用下隧道围岩力学分析及参数设计[J].铁道标准设计,2024,68(6):153-160,220,9.基金项目
国家自然科学基金项目(52078428) （52078428）
四川省杰出青年科学基金项目(2020JDJQ0032) （2020JDJQ0032）
