复杂地质隧道洞口段穿越既有抗滑桩施工方案研究  

Study on Construction Scheme of the Complex Geological Tunnel Portal Crossing the Existing Anti-slide Pile

作　　者：张立军[1] 王怀正 宋战平[2,3] 王盼 何芹 Zhang Lijun;Wang Huaizheng;Song Zhanping;Wang Pan;He Qin(Sinohydro Bureau 7 Co.,Ltd.,Chengdu 611130,China;School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi'an 710055,China)

机构地区：[1]中国水利水电第七工程局有限公司,四川成都611130 [2]西安建筑科技大学土木工程学院,陕西西安710055 [3]陕西省岩土与地下空间工程重点实验室,陕西西安710055

出　　处：《市政技术》2023年第10期181-188,共8页Journal of Municipal Technology

基　　金：国家自然科学基金资助项目(52178393);陕西省创新能力支撑计划-创新团队(No.2020TD-005)。

摘　　要：复杂地质条件下隧道洞口段施工对围岩扰动较大,容易发生滑塌现象,以四川省攀枝花市阳光隧道工程为例,采用Midas GTS NX软件建立隧道洞口段三维模型,探讨了在扶壁式挡墙+置换桩的综合治理措施下,隧道和置换桩结构以及边坡位移场和应力场的变化特征,分析了该施工方案的合理性,并预测了边坡潜在滑动面以及隧道开挖薄弱部位。通过研究可知,隧道边墙以及破桩区上部既有抗滑桩处为施工薄弱环节;隧道拱顶的最大沉降值为-25.07 mm,置换桩结构X、Y向最大位移分别为2.87、-4.47 mm,边坡安全系数为1.70,均满足施工规范要求;典型断面拱顶沉降以及净空收敛均满足施工设计控制值要求。该施工方案对后续复杂地质条件下隧道开挖具有一定的参考价值。In complex geology,the construction of tunnel portal has great disturbance to the surrounding rocks and often cause slides.Based on the Yangguang Tunnel Project in Panzhihua City,Sichuan Province,a 3D numerical model of the tunnel portal is established by Midas GTS NX software.Under the comprehensive treatment measures of supporting wall retaining wall+altered pile,the variation characteristics of tunnel,altered pile structure and displacement field and stress field of the slope are discussed.The rationality of the construction scheme is analyzed,and the potential sliding surface of the slope and the weak parts of the tunnel excavation are predicted.The research shows that the existing anti-slide piles on the side wall and the upper part of the broken pile area are the weak links;The maximum settlement value of tunnel vault is-25.07 mm.The maximum displacement of altered piles in X and Y direction is 2.87 mm and-4.47 mm respectively.The slope safety factor is 1.70.All meet the construction requirements;Both the settlement and headroom convergence of typical section arch meet the construction design control value.The construction scheme has reference value for the subsequent excavation under complex geological conditions.

关 键 词：隧道 洞口段 昔格达地质 抗滑桩 数值模拟 置换桩结构 

分 类 号：U455[建筑科学—桥梁与隧道工程] TU457[交通运输工程—道路与铁道工程]