极软岩大变形隧道交叉口段主被动支护技术应用  

Active and passive support technologies applied at intersection of soft rock tunnel with large deformation

作　　者：皮圣 范晓锋 王明年[1] 梁禹 PI Sheng;FAN Xiaofeng;WANG Mingnian;LIANG Yu(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan-Tibet Railway Co.,Ltd.,Chengdu 610043,China;School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China;State Key Laboratory for Tunnel Engineering,Guangzhou 510275,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]川藏铁路有限公司,四川成都610043 [3]中山大学土木工程学院,广东珠海519082 [4]隧道工程灾变防控与智能建养全国重点实验室,广东广州510275

出　　处：《铁道科学与工程学报》2025年第1期221-234,共14页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52378427);广东省自然科学基金资助项目(2023A1515030258,2024A1515012623)。

摘　　要：软弱围岩隧道大变形控制措施主要包含以大刚度钢架、复合式衬砌主导的被动支护技术,以高强预应力锚杆(索)为代表的主动支护技术,主被动支护结合的多层支护变形控制技术,以及让压支护技术等。然而实际工程中支护模式的选择仍是一个难题。本文依托中国西南地区铁路某隧道工程,研究运用主、被动综合支护技术解决极软岩大变形隧道交叉口段挑顶期间突发的支护结构持续变形失稳难题,并对施工期间的初支与二衬间接触压力、钢管立柱压力、初支结构变形收敛、二衬混凝土应力等进行监测和分析。研究结果表明:交叉口段采用“双层初支+Φ325钢管立柱支撑”的被动支护,可遏制初支结构拱部前期快速下沉;拱部采用20m长Φ76自进式长锚管主动加固地层,实现以锚代撑;采用大刚度I25b单层初支快速封闭成环,尽早提供支护抗力限制围岩持续变形;按照“分区施工、分段封闭”原则,快速施作3m/6m短二衬锁口以控制围岩长期蠕变。历时275d最终完成了交叉口段二衬施工,解除了交叉口段支护结构持续变形失稳风险。该项综合支护技术的成功应用可为类似工程提供有益借鉴。The control measures for soft rock tunnels with large deformation primarily encompass passive support technologies is often characterized by rigid steel frame and composite linings.Active support technologies is exemplified by high-strength prestressed anchor(cable),multi-layered support deformation control technologies combined with active and passive support,as well as yielding support technologies.However,the selection of supports in practical engineering remains a challenging problem.Based on a railway tunnel project with extremely soft surrounding rock in southwest China,this paper investigated the utilization of active and passive comprehensive support technique to address the issues of continuous deformation and instability of supporting structures during ripping construction at intersection.Additionally,the contact pressure between the primary and secondary lining,the pressure of steel pipe columns,the deformation of primary support structure and the stress of secondary lining were monitored and analyzed.The results are drawn as follows.The implementation of“double primary support+Φ325 steel pipe column support”passive support in the intersection section effectively mitigates rapid arch settlement of initial support.The 20 m longΦ76 self-drilling long anchor pipes have been adopted at the arch for active reinforcement,achieving“anchoring replacing supporting”.High-stiffness I25b single-layer initial support are used for rapid enclosure,providing early support resistance to restrict continuous deformation of the surrounding rock.3 m/6 m short secondary lining lock is quickly constructed in accordance with the principle of“partition construction and lining closure”,which can control the long-term creep of surrounding rock.It took 275 days to complete the second lining construction at the intersection section,which relieved the risk of continuous deformation and instability of the support structures.The successful application of this comprehensive support technique can provide valuable referenc

关 键 词：铁路隧道 极软岩大变形 交叉口 钢管立柱支撑 以锚代撑 主被动支护 

分 类 号：U455[建筑科学—桥梁与隧道工程]