浅埋暗挖隧洞下穿高速公路路基沉降控制  

Settlement control of highway roadbed under shallow tunnel underpass construction conditions

作　　者：李建贺 许然 高仝 欧阳林 杨正基 LI Jianhe;XU Ran;GAO Tong;OUYANG Lin;YANG Zhengji(Key Laboratory of Water Grid Project and Regulation of Ministry of Water Resources,Changjiang Survey Planning Design and Research Co.,Ltd.,Wuhan 430010,China;Construction and Administration Bureau of Water Diversion Project in Central Yunnan,Kunming 650032,China)

机构地区：[1]长江勘测规划设计研究有限责任公司水利部水网工程与调度重点实验室,武汉430010 [2]云南省滇中引水工程建设管理局,昆明650032

出　　处：《清华大学学报（自然科学版）》2024年第7期1252-1263,共12页Journal of Tsinghua University(Science and Technology)

基　　金：水利部重大科技项目(SKS-2022103);云南省重大科技专项计划资助项目(202102AF080001-02);水利青年人才发展资助项目(GFKY1502S22022)。

摘　　要：浅埋大跨度隧洞在软弱地层中下穿高速公路施工引起的路基沉降,一直都是地下工程设计和施工面临的突出技术难题之一。该文依托滇中引水工程香炉山隧洞,采用现场监测和数值模拟的方法,对隧洞下穿高速公路施工中的地表沉降、围岩变形控制方案及过程进行探讨,分析隧洞开挖过程中顶拱和路基的沉降变形规律及其影响因素。研究结果表明:浅埋大跨度隧洞掌子面前方围岩预收敛变形在顶拱总沉降变形中占比较高,施作掌子面超前支护,以减小掌子面挤出变形和前方围岩的预收敛变形,对提高围岩稳定性、降低地表沉降作用显著;相比加强支护参数,改善施工工艺对控制路基沉降的效果更为明显,优化后的四台阶工法通过“预留核心土、临时仰拱+竖撑支护、同台阶左右错开”等方式,有效约束围岩变形和应力释放,充分调动支护结构的承载性能,取得了较好的应用效果。研究结果可为类似复杂条件下,隧洞下穿高速公路施工提供参考。[Objective]The settlement of roadbeds caused by the construction of shallow large-span tunnels passing under highways in soft strata has always been one of the outstanding technical difficulties encountered in underground engineering.The key to controlling the settlement of highway roadbeds is to restrain the deformation and stress release of tunnel surrounding rock as much as possible.This study thoroughly analyzes the scheme and process of controlling the settlement of roadbeds and the deformation of surrounding rock in the construction of tunnels under highways.Furthermore,it analyzes the settlement pattern and influencing factors of the top arch and roadbed in the tunnel excavation process.[Methods]Based on the Xianglushan Tunnel Project,this study adopts on-site monitoring and numerical simulation and conducts comparative experiments through four design and construction schemes to analyze the influences of systematic support,over-advance support,and construction process on the settlement and deformation of the tunnel vault and roadbed.[Results]The preconvergence deformation of the surrounding rock in front of the palm face of the shallow-buried large-span tunnel accounted for a relatively high percentage of the total displacement of the top arch.It accounted for about 79%of the total displacement of the top arch in the construction of the Xianglushan Tunnel under the highway.After applying overrun support,the extrusion deformation of the tunnel face and the preconvergence deformation of the surrounding rock in front of the tunnel were substantially reduced,the stability of the surrounding rock of the tunnel was improved,and the highway foundation settlement was reduced.The highway foundation settlement was reduced by about 26.4%,while the tunnel vault settlement was reduced by about 31.3%.Compared with strengthening the initial support parameters,the adjusted construction approach was more effective in controlling the settlement of highway roadbeds.The adjusted construction approach,which included measures s

关 键 词：隧洞 浅埋暗挖 下穿高速公路 结构安全 路基沉降 

分 类 号：TP393.1[自动化与计算机技术—计算机应用技术]