摘要
莆炎高速黄芨隧道出口右线入洞段,位于斜坡下部,硬塑状粉质黏土覆盖层厚度为3~6 m。施工期间连遇暴雨,隧道开挖时在左导洞及拱顶出现局部塌陷,为有效治理,在总结前人研究基础上分析了塌陷成因,并系统性提出治理措施和施工期间注意事项,最终进行治理效果反馈。结果表明:该段边坡下方遇水极易软化的超薄硬塑状粉质黏土覆盖土层是塌陷的内在因素;施工期间持续降雨形成的丰富地表水和地下水是塌陷的外在因素;施工过程中未采取针对性的处理措施是坍孔的重要因素。采取坍孔扎筋喷浆回填+防排水+局部注浆加固+开挖工序调整的综合治理措施,可取得较好的治理效果,治理后监控数据较为稳定。该研究可为类似工程提供参考与借鉴。
The right entrance section of Huangji Tunnel exit at Puyan Expressway is located at the lower part of the slope.The thickness of hard plastic silty clay cover is 36 m.During the period of heavy rain,local collapse occurred in the left guide and vault during tunnel excavation.In order to effectively treat the collapse,the research foundation of predecessors is summarized,the cause of collapse is analyzed,and the treatment measures and construction are systematically put forward.Finally analyze the governance effect.The results show that the super-thin hard plastic silty clay overlay under the slope which is easily softened by water and the abundant surface water and groundwater formed by continuous rainfall during construction are the internal and external factors of the collapse,respectively.It is not to adopt specific treatment measures in the construction process as important factor for the collapse.The comprehensive treatment measures of slump hole,reinforcement and shotcrete backfilling,waterproof and drainage,local grouting reinforcement and excavation process adjustment can achieve good results,the monitoring data after the governance is relatively stable.This study can provide useful reference for similar projects.
作者
宁赋岩
NING Fuyan(No.2 Engineering Co.,Ltd.of China Railway 18 Bureau Group,Sanming 365004,China)
出处
《现代交通技术》
2020年第5期27-31,共5页
Modern Transportation Technology
基金
工程材料与结构加固福建省高校重点实验室(三明学院)开放基金项目(B1700012)。
关键词
偏压隧道
入洞段
超薄覆盖层
塌陷治理
biased tunnel
entrance section
ultra-thin overburden
collapse treatment
