采空塌陷区管土相互作用特征分析

文章分析了采空塌陷作用下油气管道的受力特征,将采空区地面塌陷过程中塌陷土体与管道的相互作用分成了下塌土蠕变、管体局部暗悬、管体完全悬空外露和土体突发沉陷4个阶段。基于抗大变形钢特性及应变设计理念的管体应力—应变关系,对Ramberg-Osgood本构关系进行了二次开发。结合急倾斜煤层开采实例,利用FLAC3D数值模拟计算了塌陷宽度相同条件下,不同土体下沉变形时管体与地表土体相互作用及变形的关系,验证了管道在受采空塌陷作用下经过的各个阶段及受力特征。

Characteristics of pipe-soil interaction in mining collapse areas

The mechanical characteristics of oil and gas pipeline in mining collapse areas was proposed according to the effects of mining areas and properties of pipe material.The effects of subsidence imposed on pipeline are divided into soil creeping,local span,free span,and soil subsidence respectively.Base on the stress-strain relationship of high deformability steel and strain deign,Ramberg-Osgood material stress-strain model was redeveloped.The relationship of pipe-soil interaction of different vertical displacement and the same subsidence width were provided by FLAC3D numerical simulation with an example of steep-inclined coal seam mining in west China,and each statute of the mechanical characteristics under the effects of subsidence was verified.