采空塌陷区埋地输气管道的变形及受力分析

针对采空塌陷对输气管道的潜在威胁，采用管道－土壤相互作用（PSI）单元，结合三向土弹簧非线性模型，建立采空塌陷区埋地输气管道的有限元计算模型，分析了不同管径、壁厚和内压影响下管道的变形和受力规律，并确定最大变形和最大受力的位置。结果表明:适当增加壁厚和减少内压能有效提高管道的安全性；最大Von-Mises应力和最大竖向应变位置均在内边缘塌陷区且靠近中间塌陷区；最大轴向应力和最大轴向应变位置均位于中间塌陷区两侧。所得结果对埋地输气管道穿越采空区的安全防护具有一定参考价值。

Analysis on deformation and stress of buried gas pipeline in mined-out subsidence area

Aiming at the potential threats of mined-out subsidence to buried gas pipeline, a finite element calculation model of buried pipeline in mined-out subsidence area was established by using the pipe-soil interaction (PSI) element and combining with three-dimensional soil spring nonlinear model. The regulations of deformation and stress for pipeline under the influence of different pipe diameter, wall thickness and inner pressure were analyzed, and the positions with the maximum deformation and maximum stress were determined. The results showed that the appropriate increase of wall thickness and decrease of internal pressure can effectively improve the safety level of pipeline. The maximum Von-Mises stress and vertical strain are located around the inside edge subsidence area and near the middle subsidence area, and the maximum axial stress and axial strain are located on both sides of the middle subsidence area. The conclusion can provide some valuable reference for the safety protection of buried gas pipeline crossing the mined-out subsidence area.