隧洞松动圈厚度确定方法及支护设计

Determination method of loose circle thickness of a tunnel and support design

围岩松动圈测量是判断围岩整体稳定性、确定隧洞支护形式的关键所在。结合新疆某隧洞工程的具体实践,采用理论模拟计算和超声波测试方法,对Ⅲ类凝灰质砂岩隧洞的松动圈进行研究,并对松动圈厚度按照Mohr-Coulomb准则分别进行理论计算和数值模拟。大量采集洞周围岩波速,确定现场超声波测试松动圈厚度的判别方法,再将计算结果与现场超声波测试成果对比分析,从而指导设计进一步优化支护参数。

The measurement of surrounding rock loose zone is the key to judge the overall stability of surrounding rock and determine the form of tunnel support.Combined with the practice of a tunnel project in Xinjiang,the loose zone of class III tuffaceous sandstone tunnel is studied by using theoretical simulation calculation and ultrasonic testing method,and the thickness of the loose zone is calculated and simulated according to Mohr Coulomb criterion.A large number of rock wave velocities around the tunnel are collected to determine the judgment method of the thickness of the loose circle by ultrasonic testing on site,and then the calculation results are compared with the results of ultrasonic testing on site,so as to guide the design and further optimize the support parameters.