煤矿长壁开采条件下埋地管道的变形破坏规律研究

发布时间：2019-03-13 09:30

【摘要】：近年来随着煤矿资源的大量开采,引起的地面塌陷已影响了油气管道的安全运营,管道的失稳破坏已经引起技术人员和科研学者的普遍关注,但目前跨采空区的油气管道的安全性研究尚不成熟,对长壁开采过程中的不同开采阶段引起的管道变形破坏特征研究较少。本文以西气东输管道在山西蒿裕煤矿段为研究对象,选取适合大变形模拟的FLAC3D有限差分软件,选取适合模拟管-土作用的结构单元,借助MIDAS GTS NX进行起伏地形三维模型的建立,对不同开采阶段管道的变形破坏情况进行分析,并将模拟所得数据与实际监测数据进行对比,保证所建立的模型与所用的岩土参数的可靠性。研究结果为沉陷区埋地管道的监测和防护提供了理论依据。本文主要得到以下结论:(1)Liner结构单元即具备管道薄壳的特性,又可以模拟管-土间的相互作用关系,故而在FLAC3D中更适合管道的模拟。(2)整个开采过程中最大下沉点均位于各开采阶段采空区中心偏下山方向,第6步开采后管道附近地表出现隆起现象,第7步开采后,地表沉陷盆地下沉量发生突变。(3)管道变形后成漏斗状,下沉值随开采进行逐渐增大,最大下沉点位于各开采阶段采空区中心偏下山方向。(4)第6步开采结束后,管-土离层对于管道的安全性产生了威胁,管道有较大范围的悬空段,第7步的开采使得悬空范围内的管道出现了应力集中现象。(5)第7步开采结束后,管道部分拉应力区应力大于管道许用应力,最大拉应力为4.42e8,采空区内侧(x=240m)的安全系数为0.92,处于危险状态,停采线外侧(x=410m)的安全系数为1.11,接近于危险状态。所有开采阶段的压应力均未超过管道的许用应力;
[Abstract]:In recent years, with the large-scale mining of coal resources, the ground collapse has affected the safe operation of oil and gas pipelines, and the instability and destruction of pipelines has aroused the general concern of technicians and researchers. However, at present, the research on the safety of oil and gas pipelines across goaf is not mature, and the research on the characteristics of pipeline deformation and failure caused by different mining stages in the process of long-wall mining is less. In this paper, the west-to-east gas pipeline in Shanxi Haoyu coal mine section as the research object, select the FLAC3D finite difference software suitable for large deformation simulation, select the suitable structural element to simulate the pipe-soil action, with the help of MIDAS GTS NX to carry on the undulating terrain three-dimensional model establishment, The deformation and failure of pipelines in different mining stages are analyzed, and the simulated data are compared with the actual monitoring data to ensure the reliability of the established model and the geotechnical parameters used. The results provide a theoretical basis for the monitoring and protection of buried pipelines in subsidence areas. The main conclusions of this paper are as follows: (1) the Liner structural element not only has the characteristics of thin shell, but also can simulate the interaction between pipe and soil. Therefore, it is more suitable for pipeline simulation in FLAC3D. (2) during the whole mining process, the maximum subsidence point is located at the center of the goaf in the direction of downhill. After the sixth step of mining, the surface near the pipeline appears uplift phenomenon, and after the seventh step of mining, there is a uplift phenomenon near the surface of the pipeline. (3) the pipe becomes funnel-like after deformation, and the subsidence value increases gradually with mining. The maximum subsidence point is located at the center of the goaf in the direction of downhill. (4) after the sixth step of mining, the subsidence value increases gradually. (4) after the sixth step of mining, the subsidence is located in the center of the goaf. (4) after the end of the sixth step, The pipe-soil separation layer poses a threat to the safety of the pipeline, the pipeline has a large range of suspended segments, and the seventh step of mining causes the pipeline to appear stress concentration phenomenon in the suspended area. (5) after the seventh step of mining, the stress concentration phenomenon appears in the pipeline. (5) after the end of the seventh step mining, The maximum tensile stress of the pipeline is 4.42e8, the safety factor of the inner part of the goaf is 0.92. it is in a dangerous state, and the safety factor of the outer side of the stoppage line is 1.11, the maximum tensile stress of the pipeline is 4.42e8, the safety factor of the inner part of the goaf is 0.92, and the safety factor of the outer side of the stoppage line is 1.11, Close to danger. The compressive stress of all mining stages does not exceed the allowable stress of the pipeline;
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD823.4;TE973

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