高地应力软岩隧道塌方处置措施及处置效果评价

Treatment Measures and Result Evaluation of Collapse in Soft Rock Tunnel with High Ground Stress

结合工程实例,综合地质条件、设计和施工情况分析高地应力软岩隧道塌方事故发生原因,详细阐述了实际工程中塌方处置措施,并结合《铁路隧道设计规范》对处置后隧道二次衬砌进行安全性评价。通过隧道内塌方体土方量估算塌腔高度,计算出塌方造成的松散岩土体作用在隧道衬砌结构上的竖向荷载,采用荷载-结构模型,得出二次衬砌结构内力,对二次衬砌进行安全性评价。根据评价结果,通过注浆固结塌方体、设置套拱及拱部钢花管注浆加固临近段支护结构,采用拱部管棚加固+局部径向注浆+注浆回填处理塌腔,之后再进行短进尺拆换塌方段支护结构的方法,能有效处置高地应力软岩隧道塌方,保证施工安全和结构可靠。

Combined with engineering cases,geological conditions,design and construction situations,the causes of the collapse of the high ground stress soft rock tunnel are analyzed,collapse treatment measures in the actual project are elaborated in detail,and the safety evaluation of the secondary lining of the tunnel after treatment is carried out following the Code for Design of Railway Tunnels.The height of collapse cavity is estimated by the earthwork volume of collapse body in tunnel,and the vertical load of loose rock and soil caused by collapse on tunnel lining structure is calculated.The internal force of the secondary lining structure is calculated by using load structure model,and the safety of secondary lining is evaluated.According to the evaluation results,consolidation of collapse body by grouting is implemented to set up arch and adjacent support structure of arch steel pipe grouting reinforcement.Arch pipe shed reinforcement,local radial grouting reinforcement and grouting backfill are employed to deal with collapse cavity,and short footage replacement of collapse section support structure is used to effectively cope with high ground stress soft rock tunnel collapse and ensure construction safety and structural reliability.