采空沉陷区埋地管道应力变形分析及远程监测

发布时间：2018-02-27 07:32

本文关键词： 煤矿开采埋地管道有限元悬空试验远程监测　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：采空沉陷区有可能造成地表沉降变形、碎裂甚至塌陷等次生地质灾害。当管道需要通过地表移动变形区时,将造成埋地油气管道的大范围变形甚至悬空,对管道的安全极为不利。论文开展油气管道工程穿越采空区管道的应力变形变化特征分析、失效评判标准研究及管道远程监测,有利于防范采空区灾害发生和评估采空区不良地质对油气管线威胁,为采空区管道的设计、建设和管理维护提供理论依据和技术参考。首先,研究了受采空沉陷区地表移动影响下埋地管道的变形特征。针对沉陷区埋地管道,在管道柔性判据成立的条件下,以地表下沉和横移变形表示管道变形曲线,分析了管土间的轴向相互作用关系。在此基础上分析采空沉陷区管道受力的特点,结合概率积分法、大挠度梁理论、弹性地基梁理论、管土作用双线性等理论,给出了管道物理伸长和几何变形间的协调方程。通过对算例的分析,能够得出采空沉陷区管道的受力特点。其次,对于采空区空间位置的变化和不同的开采工况,建立煤矿区开采过程油气管道的有限元仿真计算模型和采空塌陷悬空管道的仿真计算模型,对管道不同工况(管线方向与工作面推进方向不同夹角、不同倾斜角度倾斜煤层、不同埋深、不同内压)开采的影响进行研究,分析了管道的力学行为及变形演化规律。通过悬空管道试验验证了悬空管道仿真计算模型的正确性,并对采空塌陷区悬空管道力学状态分析,采用基于应力和基于应变两种不同理论对悬空管道进行失效分析,确定了悬空管道基于应变失效的容许跨度和极限跨度。分析结果表明：在采空区铺设管道工程中,管线走向应尽可能与煤层开采工作面推进方向成90°夹角时为最优铺设方向；矿区较平缓的倾斜煤层开采过程中对管道的影响比倾斜角度较大时的倾斜煤层开采时对管道的影响大；矿区管道应以浅埋为宜,同时为了降低管土间的轴向摩擦作用,宜选用低摩擦的回填材料；采空塌陷管道处于悬空状态下,从应变分析角度对管道悬空下沉过程中的力学行为、管道的安全状态分析具有切实的帮助；失效评判标准取极限应变2%来判定悬空管道失效是合理的。最后,针对新疆芦草沟煤层采空区地质特征,结合鄯-乌线管道的潜在危害以及在煤矿采空区的实际情况,提出可行的监测方法。数据分析表明,此远程监测方法能够准确监测得到管体在采空区地表移动中应力、应变的变化特征和变化量,为长输管道穿越矿山采空区的安全维护提供了经济可行的解决方案。
[Abstract]:The mining subsidence area may cause surface subsidence and deformation, fragmentation and even collapse of secondary geological disasters. When the pipeline needs through the surface movement and deformation zone, will result in a wide range of buried oil and gas pipeline deformation even vacant, the pipeline is not safe. The development of oil and gas pipeline crossing engineering Mining goaf pipeline stress and deformation change characteristics analysis, research and evaluation criteria of pipeline failure remote monitoring, is conducive to the prevention of goaf disaster occurrence and evaluation of goaf bad geology of oil and gas pipelines is threatened, for the design of goaf mining pipeline, construction and maintenance management to provide theoretical basis and technical reference.
First, study the deformation characteristics of mining subsidence area by surface movement under the influence of underground pipeline. For buried pipeline, the pipeline in the establishment of flexible criterion under the condition of surface subsidence and horizontal deformation in said pipeline deformation curve, analyzed the axial tube soil interaction relationship. Based on the analysis of characteristics of mining subsidence area of pipeline stress, combined with probability integral method, large deflection beam theory, the theory of elastic foundation beam, pipe soil interaction bilinear theory, coordination equation of pipe physical and geometric deformation between the elongation is presented. Through the analysis of example, to conclude that the mining subsidence area of pipeline stress characteristics.
Secondly, the change of goaf spatial location and different mining conditions, the establishment of finite element simulation of coal mine mining process of oil and gas pipeline and the calculation model of mining subsidence simulation of suspended pipeline calculation model of pipeline under different conditions (line direction and face advancing direction with different angle, tilt angle of inclined coal seam, different depth, different internal pressure) of mining influence, analyzes the mechanical behavior and deformation evolution law. Through the suspended pipeline pipeline test verified the correctness of the suspended pipeline simulation model, and analysis of mining subsidence area of suspended pipeline mechanical state, the stress and strain based on two kinds of theories of suspended pipeline based on the failure analysis, determine the allowable limit span of suspended pipeline span and the failure strain. Based on the analysis of the results showed that: in the goaf of laying pipeline, pipe line to be As far as possible with the coal mining face advancing direction 90 degree angle as the optimal laying direction; effect on the impact of coal mining on the slope of pipeline pipeline inclined coal seam mining process in the mining area is relatively flat is larger than the tilt angle of pipe should be buried in shallow mining area; at the same time is appropriate, in order to reduce the pipe axial friction effect soil, backfill material should choose low friction; mining subsidence pipe in a suspended state, from the angle of strain analysis of mechanical behavior of suspended pipeline in the sinking process, analysis of the safety state of pipeline with practical help; failure criterion of limit strain 2% to determine the suspended pipeline failure is reasonable.
Finally, according to the Xinjiang Lucaogou coal mined out area geological features, combined with the potential hazards of Shan Wu line pipe and the actual situation of goaf in coal mine, the monitoring method is feasible. The data analysis shows that this method can get the accurate monitoring of remote monitoring pipe in the goaf surface stress move, change the characteristics and changes of the amount of strain, provide economic and feasible solution for safety maintenance through the goaf of long distance pipeline.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE973

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