非圆形隧洞收敛-约束特征曲线的数值求解方法

利用应力释放法原理,在收敛-约束解析法基础上,提出了适合任意断面隧洞的收敛-约束特征曲线数值求解方法,通过与收敛-约束解析法对比验证该方法的有效性,并与常用的数值方法进行对比,最后对收敛-约束特征曲线数值求解方法的计算误差进行分析.研究结果表明:收敛-约束特征曲线数值求解方法适合非圆形隧洞,由于通过施加节点支撑反力实现应力释放,该方法同样适合应力状态复杂的隧洞;以滇中引水工程为例,将收敛-约束特征曲线数值求解方法与收敛-约束解析法的计算结果进行对比,验证了收敛-约束特征曲线数值求解方法的有效性;收敛-约束特征曲线数值求解方法计算结果存在一定的误差,其整体相对误差小于10%.收敛-约束特征曲线数值求解方法的适用性更加广泛,可为隧洞工程的初期支护优化设计及安全性评价提供参考,具有一定的工程应用价值.

Numerical Solution Method of Non-circular Tunnel Convergence-confinement Characteristic Curve

By using the principle of stress release method, a numerical solution method of convergence-confinement characteristic curve was proposed for tunnels with various cross-sections based on the convergence-confinement analysis method. The validity of the proposed method was verified by comparison with the convergence-confinement analytical method, and compared with the usual numerical methods. Finally, the calculation error of the numerical solution method for convergence-confinement characteristic curve was analyzed. The results show that the numerical solution method of convergence-confinement characteristic curve is suitable for non-circular tunnel, and due to the stress release achieved by applying support reaction to nodes, the method is also suitable for the tunnel with complicated stress condition. Taking the Dianzhong diversion project as an example,the numerical solution method of convergence-confinement curve was compared with the calculation results of the convergence-confinement analytical method, and the validity of the numerical solution method of convergence-confinement curve was verified. Despite some error in the result of the numerical solution method of convergence-confinement curve, the overall relative error is less than 10%. The application of the numerical solution method for convergence-confinement characteristic curve is more extensive,which can provide reference for the optimization design of primary support and safety evaluation of tunnel engineering, and the numerical solution method has a certain value of engineering application.