考虑注浆加固的隧道稳定性上限有限元法研究  

Study on the Upper Bound Finite Element Method of Tunnel Stability Considering Grouting Reinforcement

作　　者：李福东 刘伯岩 陈子昂 朱诚 丰土根[3] 张箭 LI Fudong;LIU Boyan;CHEN Ziang;ZHU Cheng;FENG Tugen;ZHANG Jian(CCCC-Second Highway Bureau Fourth Engineering Co.Ltd.,Luoyang 471013,Henan China;Nanjing Metro Construction Co.Ltd.,Nanjing 210017,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Rail Transit Division of China Communications Construction Company Limited,Beijing 101300,China)

机构地区：[1]中交二公局第四工程有限公司,河南洛阳471013 [2]南京地铁建设有限责任公司,南京210017 [3]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [4]中国交建轨道交通事业部,北京101300

出　　处：《河南科学》2024年第12期1762-1772,共11页Henan Science

基　　金：国家自然科学基金项目(52178386)。

摘　　要：盾构施工过程中,壁后注浆方法可有效防范隧道失稳、地表沉降超限等问题.然而,注浆加固隧道的破坏机制尚不清晰.基于上限有限元方法,通过求解不同参数下注浆加固隧道的极限支护力系数、地层破坏模式、地表失稳特征曲线来研究不同地层参数对注浆加固隧道稳定性的影响.研究结果表明:考虑注浆加固影响时隧道的极限支护力较未考虑注浆加固时可降低323.51 kPa.在加固参数增大过程中,隧道极限支护力系数呈线性下降趋势,且下降速度受注浆层参数影响,k2与k1越大,下降速度越快,滑移线起始位置沿着隧道轮廓逐渐向隧道底部扩展,隧道周边土体的破坏范围集中在隧道边墙及顶板上方.注浆加固隧道能有效抑制地表沉降.随着注浆层厚度的增加,地表最大沉降系数不断减小.注浆层摩擦角增大15°时,地表最大沉降系数减小40%.In the process of shield construction,the backfill grouting method can effectively prevent the tunnel instability and the surface settlement exceeding the limit.However,the failure mechanism of tunnel reinforced by grouting is still unclear.Based on the upper limit finite element method,the influence of different stratum parameters on the stability of tunnel reinforced by grouting is studied by solving the ultimate supporting force coefficient,formation failure mode and surface instability characteristic curve of tunnel reinforced by grouting under different parameters.The results show that the ultimate support force of the tunnel under the consideration of grouting reinforcement is 323.51 kPa lower than that without the consideration of grouting reinforcement.In the process of increasing the reinforcement parameters,the ultimate support force coefficient of the tunnel shows a linear downward trend,and the decline speed is affected by the parameters of the grouting layer.The larger k2 and k1 are,the faster the decline speed is.The initial position of the slip line gradually expands along the tunnel outline to the bottom of the tunnel,and the damage range of the soil around the tunnel is concentrated above the side wall and roof of the tunnel.Tunnel reinforced by grouting can effectively restrain the surface settlement.With the increase of grouting layer thickness,the maximum surface settlement coefficient decreases continuously.When the friction angle of the grouting layer increases by 15˚,the maximum surface settlement coefficient decreases by 40%.

关 键 词：盾构隧道 极限分析 极限支护力 注浆加固 上限有限元 

分 类 号：U455[建筑科学—桥梁与隧道工程]