高速公路断层区小净距隧道稳定性分析及控制措施

Stability Analysis and Controlling Measures of Small-distance Tunnel in Fault Area of Expressway

小净距隧道施工时,左右洞相互影响较大,特别是在断层等不良地质区段,前进洞爆破恶化后进洞的围岩条件,后进洞对前进洞的围岩稳定性及结构安全存在较大影响。该文以寒牛寨隧道施工为例,介绍了该隧道采用综合地质超前预报方法成功预报了F1断层的位置,为设计单位、施工单位及时调整施工方案提供了依据,并制定了针对断层区的监测方案,对塌方和大变形进行了及时预警,及时避免左洞与右洞初支出现严重变形等涉及到施工安全以及隧道结构安全的情况,为断层破碎带动态设计优化提供了依据。

In the construction of small-distance tunnel,the influence of the left and right holes on each other is larger,especially in the defective areas,such as fault and so on. The surrounding rock conditions of the hinder hole will be deteriorated by the ahead hole blasting,and there are great inflects on the stability and structural safety to the ahead hole by the hinder hole. Taking the construction of Hanniuzhai Tunnel as an example,this paper introduces the comprehensive geological advanced prediction method successfully predictes the location of F1 fault,which provides the basis for design units and construction units to timely adjust the construction plan. The monitoring program aimed to the fault area is formulated. The landslides and large deformation are warned timely. The serious deformation of primary support of left and right holes which involves construction safety and tunnel structure safety is avoided. It provides a basis for dynamic design and optimization of fault fracture zone.