小垂距交叉软岩隧道现场监测分析

针对公路与铁路小垂距交叉软岩隧道的特点,以云南某上穿公路隧道为背景,对该隧道右幅交叉段进行隧道净空收敛、围岩内部结构应力、围岩深部位移等项目的监测。根据监测结果,分析该隧道的围岩和支护结构的变形以及受力特点。结果表明,隧道右幅交叉段Ⅴ级围岩采用三台阶临时仰拱法开挖是可行的,能够有效地控制围岩变形,围岩稳定变形时间在30 d左右。监测成果可用于对隧道稳定性进行评估与预警,以便及时调整支护参数,保证隧道施工安全性。

Site Monitoring Data Analysis of Tunnels with Small Clear Spacing Close Cross Soft Rock

Based on a tunnel project in Yunnan province which pass a railway and surrounded by soft rock ,it is critical to make a comprehensive monitoring on the mechanical characteristics of the tunnel during construction .According to its characteristics ,some monitoring focusing on the convergence deformation ,structure stress and rocks displacement etc has been carried out previously .The deformation and stress properties of surrounding rocks and supporting system are ana-lyzed according to measured data .The results show that it is feasible to excavate the surrounding rock by using the three step temporary inversion method .The method can effectively control the deformation of the surrounding rock and the time stable deformation of the surrounding rock is about 30 days .The measured data can be used to assess the stability of the tunnel and provide early warning ,and adjust the support parameters timely and ensure the safety of the tunnel construc-tion .