综合安全系数法在隧道安全性评价中的应用

在运用综合安全系数法计算通常处于偏心受压状态的隧道结构时,需对每一个内力组合先通过试算确定结构的偏心受压状态,再计算结构的安全系数,计算过程繁琐,工作量大。为了使综合安全系数法的使用更简便,结合钢筋混凝土结构偏心受压构件计算方法及规范要求,推导出偏心受压受力状态下,安全系数为2.0时的M-N临界方程。以辽宁省两条隧道为例,对其进行安全性检验。将获得的结构内力与临界方程绘制于M N坐标系下,通过将内力与临界方程曲线进行比对,判断出了衬砌结构的安全情况。该方法可以快速、直观、有效地定性判断隧道的安全性,推导结果可在类似工程中应用。

Application of comprehensive safety coefficient method in tunnel safety evaluation

Safety evaluation of tunnel structure stands as an important task in tunnel engineering. As one of the safety evaluation methods, comprehensive safety coefficient method has now been widely used. Due to the fact that the tunnel structure is constantly under eccentric compressed state, computational process of this method is rather complicated with a great deal of work to conform the eccentric compressed state for each internal force combination in order to get the security coefficient of the structure. In order to simplify comprehensive safety coefficient method, by combining the computational method of the eccentric compressed components of the reinforced concrete structure and the code requirement, the critical formula of M-N (with the safety coefficient being 2.0) under eccentric compressed state is deduced. Two tunnels in Liaoning Province are used as examples for safety examination. By comparing the obtained correlation curves of internal force and critical formula (at the M-N coordinate system), the judgment can be made upon whether the safety coefficient of lining structure is up to the standard or not. It is rapid, direct and efficient for tunnel safety evaluation by using the method. The deduction result could be applied in similar engineering projects.