采动影响下埋地管道与管周土相互作用及其力学响应研究

More and more buried pipelines will be affected by mining subsidence because of the increasing mining areas and the development of pipeline transport in China, so the mechanical response of buried pipelines by mining subsidence should be studied urgently. In this research project, experimental research on the interaction and the mechanical response between buried pipelines and its surrounding soil must be conducted to analyze the coordinated relationship between the buried pipelines and its surrounding soil, earth pressure around the pipeline, and distribution law of the pipeline stress induced by subsidence. A test device of transparent soil subsidence will be used in studying the deformation evolution of the soil around pipeline. In this test, the laser speckle images are recorded during soil subsidence, and the 3-D displacement field of the soil around pipeline will be obtained. Binding force calculation formula of the buried pipelines during soil subsidence will be deduced according to the test and theoretical analysis. According to the test results, theoretical analysis and evolution characteristics for the surface subsidence by mining, we will establish a simplified mechanics models for the mechanical response of buried pipelines in the stages of cooperation deformation and non-cooperation deformation between buried pipelines and surrounding soil. Then the relevant parameters of the mechanics models will be ascertained by comparative analysis from numerical simulation, laboratory tests, theoretical results and field monitoring data. So, a calculation method on the mechanical response of the buried pipelines by mining will be proposed at last. These researchs will be meaningful and have high engineering value for the pipelines safety and the rational mining near buried pipelines located in mining areas.

我国管道运输的快速发展和煤矿开采沉陷区的持续扩大，越来越多地表埋地管线将受采动沉陷影响，采动影响下埋地管道的力学响应亟待研究。本项目将利用设计的试验装置，开展沉陷土体中的管-土相互作用及其力学反应试验研究，揭示沉陷土体中的管-土变形协同关系、管周土压力及管道应力分布规律。利用设计的透明土沉陷试验系统，通过观测沉陷过程中管周土的纵、横断面激光散斑图像，可视化管周土三维变形位移场，揭示沉陷土体中管周土的运移机制。在试验及理论分析基础上，推导沉陷土体中管道纵、横断面约束力计算公式。结合采动沉陷地表变形特征，基于合理简化后建立管-土协同及非协同弯曲变形的力学分析模型。通过数值模拟、室内试验、理论分析及现场监测数据的综合分析，确定力学模型中的相关参数，提出采动影响下埋地管道力学响应的分析计算方法。本研究将对分析采动沉陷区管道安全性及科学开采管道附近滞压的煤矿资源等方面具有重要理论意义和工程应用价值。

为揭示开采沉陷土体中埋地管与管周土体的相互作用机制，本项目基于自行研制的试验系统，开展了沉陷土体中埋地管与管周土体的相互作用机制研究。结合理论分析及数值模拟，对开采沉陷中埋地管道的变形特征、力学响应、安全性评定及保护技术等进行了探索研究。取得了如下创新性成果：.（1）基于研制的试验系统，开展了沉陷土体中埋地管与土相互作用及其力学反应试验研究。得到了管-土下沉变形、管周土压力及管道应变分布规律，揭示了沉陷过程中的管-土变形协同关系、管周体土体破坏及管周约束力分布特征。.（2）基于设计的透明土沉陷试验系统，通过观测沉陷过程中管周透明土激光散斑图像，结合粒子图像测速( particle image velocimetry，简称PIV) 技术，可视化土体沉陷中管周土体内部位移场，揭示沉陷土体中管周土的运移机制。同时，为研究土与地下构筑物的相互作用研究开辟了新方法。.（3）基于煤矿开采沉陷理论，分析了工作面开采过程中管道沿线的开采沉陷规律，建立了管-土协同和非协同变形阶段的力学分析模型，提出了埋地管道附加应力的计算公式，编制了相关分析流程及计算程序，建立了采动影响下埋地管道力学响应的计算方法。.（4）根据实际工程，基于管-土协同变形关系和管道应力分析流程，得到了开采沉陷范围内埋地管道轴线方向附加应力。基于数值模拟结果分析，得到了采动沉陷区埋地管道沿线的变形、附加轴向应力和Mises应力等，并进行了埋地管道安全性进行了评定。.（5）发明了一种安全、经济、结构简单的煤矿开采沉陷区埋地油气管道保护方法。有效避免了开采沉陷对埋地油气管道的破坏性影响，实现了开采沉陷区埋地油气管道的多重科学保护。.本项目研究对分析采动沉陷区管道安全性及科学开采管道附近滞压的煤矿资源等方面具有重要理论意义和工程应用价值。