高速公路下伏急倾斜煤层采空区致灾机理与防治技术研究

发布时间：2018-04-16 06:15

本文选题：采空区 + 急倾斜煤层　；参考：《长安大学》2015年硕士论文

【摘要】：随着我国高速公路的迅速发展,全国公路网的不断完善,许多公路将不可避免的穿越采空区上方。虽然国内对高速公路下伏采空区的治理已有了许多年的经验,在采空区的勘察设计、稳定性评价和处治技术等方面积累了许多宝贵的经验,但总体来说,我国采空区高速公路建设技术还不算是成熟阶段。由于各地公路下伏采空区的工程条件差别较大,新的工程实践中仍然存在许多难题,尤其在考虑地表施工与运营荷载影响的采空区稳定性评价方法、评价依据、治理标准及工程处置技术等方面,尚未形成系统的治理理论和技术,无规范可循,也没有成熟的工程设计体系可供借鉴和指导,特别是对于急倾斜煤层采空区的处理问题,还缺乏成功的经验。本文针对急倾斜煤层的致灾机理和防治问题,以新疆乌鲁木齐绕城高速采空区治理工程为依托,采用现场踏勘、理论分析与数值模拟计算相结合的方法,对急倾斜煤层采空区修建高速公路后的沉降趋势、致灾机理与防治措施等进行了研究,主要成果如下:⑴分析了影响急倾斜煤层采空区地表稳定性的主要因素分为采矿因素和不良地质因素。总结了高速公路下伏急倾斜煤层采空区所引起的路基、桥梁、隧道和涵洞等产生不良病害情况。⑵分析了该工程中的小窑采空区和其他地勘资料中的空洞对高速公路路基稳定性的影响。该项目中基底附加应力的影响深度都能到达导水裂隙带的范围内,所以必须进行采空区空洞的处理才能满足路基的设计规范要求。⑶利用FLAC软件,建立了采空区上覆盖层厚度对比模型和采空区安全煤柱顶宽对比模型。通过对比分析得到在采空区安全煤柱上方修建公路时,采空区上覆盖层不同高度和不同安全煤柱顶宽对地面稳定性的影响。模拟结果表明:上覆盖层在一定厚度内存在着自稳性,地表沉降的最大值随着地层厚度的增加先增大后减小。煤层开挖后,安全煤柱对地层的稳定性起到了很大的作用,安全煤柱边缘也产生了变形移动区和变形破坏区。并且安全煤柱预留顶宽越宽,安全煤柱上方地层煤层开挖后地表沉降值越小。⑷通过数值模拟,分析了该工程中,公路对采空区内地表的稳定性影响很大,必须进行加固处理后,才能满足路基的设计规范要求。并根据现场实际工况,总结归纳了采空区防治技术。
[Abstract]:With the rapid development of highway in China and the continuous improvement of national highway network, many highways will inevitably cross the top of the goaf.Although there have been many years of experience in the treatment of goaf under freeway in China, many valuable experiences have been accumulated in the survey and design of goaf, stability evaluation and treatment technology, etc., but generally speaking,The construction technology of goaf expressway in China is not a mature stage.There are still many difficulties in new engineering practice, especially in the evaluation method of goaf stability considering the influence of surface construction and operation load.In the aspects of treatment standard and engineering disposal technology, there is no systematic governance theory and technology, no standard to follow, no mature engineering design system to be used for reference and guidance, especially for the treatment of goaf in steeply inclined coal seam.There is also a lack of successful experience.In view of the disaster mechanism and prevention of steep coal seam, based on the project of high speed goaf control in Urumqi, Xinjiang, this paper adopts the method of field exploration, theoretical analysis and numerical simulation calculation.In this paper, the settlement trend, disaster mechanism and prevention measures of freeway in goaf of steeply inclined coal seam are studied.The main results are as follows: 1. The main factors affecting the surface stability of goaf in steeply inclined coal seam are divided into mining factors and bad geological factors.The roadbed and bridge caused by goaf in steep inclined coal seam under expressway are summarized.The influence of cavities in small kiln goaf and other geological prospecting data on the stability of expressway roadbed is analyzed.In this project, the influence depth of the additional stress of the foundation can reach the range of the water-conducting fissure zone, so the cavities in the goaf must be treated in order to meet the requirements of the subgrade design code. 3. 3 using FLAC software.A comparison model of overburden thickness in goaf and a comparison model of roof width of safe coal pillar in goaf are established.Through the comparative analysis, the influence of different overburden height and different safety pillar top width on the ground stability is obtained when the highway is built above the safe coal pillar in goaf.The simulation results show that there is self-stability in a certain thickness of the overburden, and the maximum value of the surface subsidence increases first and then decreases with the increase of the formation thickness.After the coal seam is excavated, the safe coal pillar plays a great role in the stability of the formation, and the edge of the safe coal pillar also produces the deformation moving zone and the deformation failure zone.And the wider the width of the reserved top of the safety pillar, the smaller the ground subsidence value after the coal seam excavation above the safe coal pillar. Through the numerical simulation, it is analyzed that the highway has a great influence on the stability of the inner surface of the goaf in this project.It is necessary to reinforce the roadbed before it can meet the requirements of the subgrade design code.According to the actual working conditions, the prevention and cure technology of goaf is summarized.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U412.2;U415.6

【共引文献】