泥岩隧洞仰拱矢跨比对围岩稳定性的影响  

The Influence of Inverted Arch Rise-Span Ratio on Surrounding Rock Stability of Mudstone Tunnel

作　　者：石广斌[1] 魏娟盆 肖清 张雯[1] 来显杰 SHI Guangbin;WEI Juanpen;XIAO Qing;ZHANG Wen;LAI Xianjie(School of Resources Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学资源工程学院,陕西西安710055

出　　处：《矿业工程研究》2023年第3期1-8,共8页Mineral Engineering Research

基　　金：陕西省教育厅基金资助项目(21JK0719);国家自然科学基金青年科学基金资助项目(51904220)。

摘　　要：针对隧洞(道)工程中广泛存在软岩地层造成支护结构变形甚至破坏的问题,结合印度尼西亚佳蒂格德水电站引水隧洞现场监测的顶板沉降和边墙收缩变形数据,提出底板设置仰拱的支护方案.利用有限元软件MIDAS GTS建立不同仰拱矢跨比和侧压力系数的数值模型,反演佳蒂格德水电站引水隧洞的侧压力系数,并分析两台阶开挖隧洞围岩和初期支护结构的变形和应力规律.研究结果表明:(1)反演的佳蒂格德水电站泥岩段引水隧洞围岩的侧压力系数为1.2;(2)泥岩隧洞的仰拱矢跨比宜为1/10~1/8;(3)拱脚局部有应力集中的现象,必须对拱脚进行加固处理;(4)综合考虑佳蒂格德水电站引水隧洞的施工条件、围岩及支护结构的变形和应力、施工经济性,得出佳蒂格德引水隧洞最优矢跨比为1/10.Aiming at the problems of deformation or even destruction of support structure caused by unavoidable soft rock strata in tunnel(road)project,a support scheme of setting inverted arch on the bottom plate is put forward based on the data of roof settlement and side wall contraction deformation monitored by the diversion tunnel of Indonesia Jatigde Hydropower Station.Using finite element software MIDAS GTS,numerical models with different rise-span ratios and side pressure coefficients are established to invert the side pressure coefficients of the diversion tunnel of Jatigde Hydropower Station,and to analyze the deformation and stress laws of the surrounding rocks of the tunnel excavated by two steps and the initial support structure.Results show that(1)the inverted lateral pressure coefficient of the surrounding rock of the diversion tunnel of Jatigde Hydropower Station is 1.2;(2)the ratio of inverted arch to span of mudstone tunnel should be 1/10~1/8;(3)there is local stress concentration at the arch foot,so the arch foot must be reinforced,and(4)considering construction conditions,deformation and stress of surrounding rocks and support structure,and construction economy of the diversion tunnel of Jatigde Hydropower Station,the optimum ratio of rise to span of Jatigde diversion tunnel is 1/10.

关 键 词：软岩隧洞 仰拱 矢跨比 位移 数值模拟 

分 类 号：O319.56[理学—一般力学与力学基础]