岗乌隧道岩溶角砾岩段大变形控制技术  

Large Deformation Control Technology of Karst Breccia Section in Gangwu Tunnel

作　　者：王青松 任少强[1] 冯军武 孙星亮 罗宗帆 常得胜 WANG Qingsong;REN Shaoqiang;FENG Junwu;SUN Xingliang;LUO Zongfan;CHANG Desheng(China Railway Construction Plateau Tunnel Construction Technology and Equipment R&D Center,China Railway 20 Bureau Group Corporation,Xi’an Shaanxi 710016,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang Hebei 050043,China;No.6 Engineering Corporation Limited of China Railway 20 Bureau Group Corporation,Xi’an Shaanxi 710032,China)

机构地区：[1]中铁二十局集团有限公司中国铁建高原隧道施工技术及装备研发中心,陕西西安710016 [2]石家庄铁道大学土木工程学院,河北石家庄050043 [3]中铁二十局集团第六工程有限公司,陕西西安710032

出　　处：《中国铁路》2023年第8期24-32,共9页China Railway

基　　金：中铁二十局集团有限公司科研项目计划(重大-2013-01,YF2100SD01A,YF2000SD01B)。

摘　　要：隧道软岩大变形一直是工程界的难题,依托岗乌隧道深埋岩溶角砾岩区段大变形实例,基于数值模拟、隧道变形和结构受力现场测试,针对隧道产生大变形的机理及相应控制技术开展研究。分析结果表明:岗乌隧道岩溶角砾岩大变形区段存在明显的构造应力,属于典型的挤压型大变形,隧道开挖导致围岩形成较大的塑性区域,使得初支结构承受了较大荷载,导致拱架扭曲、初支开裂;工程实践中采用“增强超前支护+强化初支参数+优化工法+增强二次衬砌”的措施,具体包括“T76自进式超前管棚+三台阶留核心土法加临时仰拱+大预留变形量+HW175型钢+T76S大锁脚+增强二次衬砌”等手段进行预防和控制。通过对支护结构的长期监测及安全性评价,证明相应处置措施的有效性。Given the challenges posed by major deformation of tunnel’s soft rocks,the paper takes the deformed deep-buried karst breccia of Gangwu Tunnel as an example.Built on the numerical simulation and the in-situ testing of tunnel deformation and structural stress,the paper looks into the mechanism and the corresponding control technologies of major deformation.The results show that visible tectonic stress is noticed at the karst breccia section with severe deformation,a classic example of major compressive deformation.The large plastic areas formed at the surrounding rocks upon tunnel excavation leads to substantial loading at the primary support structure,leading to distorted arch and/or the cracking of primary support.The engineering practice applied enhances advance support,strengthens primary support parameters,optimizes construction methods,and enhances secondary lining.Specific prevention and control approaches includes the use of T76 self-propelled advance pipe roof,a three-step core soil retaining method with the adding of temporary inverted arch,adequate allowance reserved for deformation,the introduction of HW175 section steel,that of T76S large lock springing and enhancement of secondary lining,etc.The long-term monitoring and safety assessment of the supporting structure proves the effectiveness of the measures applied.

关 键 词：岗乌隧道 岩溶角砾岩 深埋隧道 大变形 控制技术 

分 类 号：U455[建筑科学—桥梁与隧道工程]