黄土隧道初支变形处理方法探讨

Discussion on Treatment Method of Initial Branch Deformation of Loess Tunnel

针对陕北黄土高原高速公路隧道施工中,出现的围岩突变,导致初期支护出现的大变形情况,通过对比设计资料和现场踏勘等方式,全面分析了变形产生的原因,及时有效地进行应急处置。多次组织专家论证,通过反压回填保证压力平衡,及时搭设临时加强支撑确保已变形段初期支护结构变形稳定,在换拱前对变形段初支外破碎围岩进行注浆加固,并按处理方案要求密打超前小导管等一系列安全保证措施实施的前提下,实施换拱作业,过程中严格按要求进行监控量测,最终安全高效的完成了隧道初期支护变形段的处理。

This paper analyzes the causes of deformation caused by sudden changes in surrounding rock during the construction of expressway tunnels in the Loess Plateau of northern Shaanxi,leading to large deformations in the initial support,by comparing design data and on-site reconnaissance. Timely and effective emergency response. Organized expert demonstrations many times to ensure pressure balance through back pressure backfilling,and timely set up temporary strengthening support to ensure the deformation of the initial support structure of the deformed section is stable.Before the arching,the grouting reinforcement of the broken surrounding rock of the initial section of the deformation section is grouted and strengthened. The treatment plan requires the implementation of a series of safety assurance measures such as the small-scale small catheter before the implementation of the arching operation. During the process, the monitoring and measurement are strictly carried out according to the requirements,and finally the treatment of the deformation section of the initial support of the tunnel is completed safely and efficiently.