复杂堆积体区导向井开挖及强卸荷裂隙高陡岸坡综合处治研究  

Study on Guide-well Excavation in Complex Accumulation Area and Comprehensive Treatment of High-steep Bank Slope with Strong Unloading Cracks

作　　者：冯玉涛 王伟桥 张景伟[5] 刘宪庆 徐浩娟 吴红刚 FENG Yutao;WANG Weiqiao;ZHANG Jingwei;LIU Xianqing;XU Haojuan;WU Honggang(China Railway Changjiang Transport Design Group Co.,Ltd,Chongqing 401121,China;Northwest Research Institute Co.,Ltd of C.R.E.C,Lanzhou 730000,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;School of Traffic and Transpotration,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]中铁长江交通设计集团有限公司,重庆401121 [2]中铁西北科学研究院有限公司,甘肃兰州730000 [3]重庆大学土木工程学院,重庆400045 [4]重庆交通大学交通运输学院,重庆400074 [5]郑州大学土木工程学院,河南郑州450001

出　　处：《灾害学》2024年第4期88-94,共7页Journal of Catastrophology

基　　金：重庆市自然科学基金“复杂山区大型堆积体路基变形机制及应急修复关键技术”(CSTB2022NSCQ-MSX0263);重庆市技术创新与应用发展专项重点项目“山区道路长期服役性智能评价与提升技术研究及应用”(CSTB2022TIAD-KPX0102);中国中铁股份有限公司科技研究开发计划“复杂环境路基建造与灾害防治施工技术”(2022-重大专项-07)。

摘　　要：万州长江公路大桥因三峡蓄水需增设防船撞设施。作为防撞设施关键环节的3#导向井地处长江陡崖下部的堆积体岸滩上,受库水消落、江岸强烈卸荷和库岸再造等影响,导向井处堆积体开挖支护困难、背侧70 m高陡岸坡崩塌风险大。为保障导向井施工以及防撞设施和航道的运营安全,根据项目区地形地质和构造水文特点,采用FLAC 3D有限元法对3#导向井开挖所形成的高陡岸坡稳定性进行了模拟分析,结果表明:开挖和暴雨工况下,岸坡处于欠稳定状态,存在较大的失稳风险,且在砂岩、泥岩和裂隙I交界处,存在明显的剪应力集中现象。根据仿真结果,制定了锚索地梁联合坡面喷射封闭的岸坡支护方案;比选了导向井处孤石群堆积体加固和卸荷方案,结合库水位消落和工期计划,采用了孤石群破碎清除和刷方膜袋混凝土防护方案,保证了3#导向井的安全建设。The Wanzhou Yangtze River Highway Bridge which boasted as the first Arch-bridge of the World needed to add anti-ship collision facilities due to the impoundment of the Three Gorges.As the key content of anticollision facilities construction,the third guide-well is located on the bank of the accumulation body,affected by the reservoir water dissipation,the strong unloading and the reconstruction of the reservoir bank,it is difficult to excavate and support the accumulation body at the guide-well,and there is a high risk of instability of the 70m steep bank slope.In order to ensure the safety of guide-well construction and operation of the anti-collision facilities and the Yangtze River channel,according to the topography geology and tectonic hydrological characteristics of the project area,the stability of steep bank slope formed by the excavation is simulated and analyzed using FLAC 3D finite element software,the results show that the slope is unstable under the condition of excavation and rainstorm,shear stress concentration at the junction of sandstone,mudstone and fissure is obvious.Based on the results,the supporting scheme of anchor cable ground beam combined with slope jet sealing was adopted the reinforcement and removal scheme of the boulder accumulation were studied,combined with the reservoir water level fluctuation and the schedule,the local removal and membrance bag concrete protection scheme of the accumulation was adopted,ensured the safety construction of the third guide-well.

关 键 词：复杂堆积体 崩塌孤石 卸荷裂隙 高陡岸坡 综合处治 

分 类 号：U445.556[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程] X43[环境科学与工程—灾害防治] X915.5