基于松动圈理论的软岩大变形隧道锚杆支护优化研究  

Optimization of bolt support for soft rock large deformation tunnel based on the theory of loose circle

作　　者：王睿[1,2] 张煜 黄晓东 邓祥辉[1,2] 袁岽洋 丁潇[1] WANG Rui;ZHANG Yu;HUANG Xiaodong;DENG Xianghui;YUAN Dongyang;DING Xiao(School of Civil and Architecture Engineering,Xi’an Technological University,Xi,an 710021,P.R.China;Xi’an Key Laboratory of Civil Engineering Testing and Destruction Analysis on Military-Civil Dual Use Technology,Xi’an Technological University,Xi,an 710021,P.R.China;Shaanxi Road and Bridge Group Co.Ltd,Xi’an 710000,P.R.China;Zhejiang Scientific Research Institute of Transport,Hangzhou 311305,P.R.China)

机构地区：[1]西安工业大学建筑工程学院,西安710021 [2]西安工业大学西安市军民两用土木工程测试技术与毁损分析重点实验室,西安710021 [3]陕西路桥集团有限公司,西安710000 [4]浙江省交通运输科学研究院,杭州311305

出　　处：《土木与环境工程学报（中英文）》2023年第4期74-82,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51408054);陕西省自然科学基础(2017JM5136);陕西省教育厅专项科研计划(19JK0399);浙江省交通运输科学研究院自主研发项目(ZK202104、ZK202105)。

摘　　要：在高地应力软岩区修建隧道时,由于软岩自身强度低、膨胀性强,又受高地应力挤压,若施工措施不当易发生软岩大变形,给工程建设带来巨大困难。根据围岩松动圈理论,采用统一强度准则,考虑中间主应力的影响,分析围岩应力状态,得到适用于软岩大变形隧道围岩松动圈半径计算公式。对安岚高速谢家坡隧道围岩进行弹塑性分析发现,软岩大变形隧道围岩松动圈沿横断面分布并不均匀,呈边墙大拱顶小的趋势,且随大变形级别的升高和支护反力的减小而增大。结合现场测试得到Ⅱ级大变形松动圈厚度拱顶处为6.5~7.0 m,边墙处为7.0~7.5 m;Ⅲ级大变形松动圈厚度拱顶处为7.5~8.0 m,边墙处为8.0~8.5 m,并以松动圈厚度为依据优化系统锚杆长度。对优化段监测可见,围岩变形显著减小,稳定性有效提高。When constructing tunnels in soft rocks with high ground stress,it should be considered that the soft rock has low strength and strong expansibility,and is extruded by high ground stress.Therefore,it is unavoidable to cause large deformation of soft rock if the construction measures are not appropriate,which brings great difficulties to the engineering construction.Based on the theory of surrounding rock loose circle,the unified strength criterion is adopted to analyze the stress state of surrounding rock with consideration of the influence of intermediate principal stress.Then the radius calculation formula of loose circle of surrounding rock of large deformation soft-rock tunnel is obtained.Based on the case of Xiejiapo tunnel of Anlan Expressway,it is found that the distribution of surrounding rock loose circle of large deformation soft-rock tunnel is not uniform along the cross section.And the loose circle tends to be large in the side wall and small in the vault,and increases with the increase of deformation grade and decrease of support reaction force.Combined with field test,it is found that the thickness of loose circle of gradeⅡlarge deformation is 6.5-7.0 m at vault and 7.0-7.5 m at side wall;the thickness of loose circle of gradeⅢlarge deformation is 7.5-8.0 m at vault and 8.0-8.5 m at side wall.Therefore,the length of the system bolt should be optimized based on the thickness of the loose circle.By monitoring the optimized section,it can be seen that the deformation of surrounding rock is reduced significantly and the stability is improved effectively.

关 键 词：隧道 锚杆支护 围岩松动圈 统一强度准则 中间主应力 

分 类 号：TU455.7[建筑科学—岩土工程]