煤矿老采空区上方高速公路建设安全性评价及其关键技术研究

发布时间：2018-05-18 22:10

本文选题：老采空区 + 稳定性评价　；参考：《中国矿业大学》2017年博士论文

【摘要】：近年来,我国经济快速发展,高速公路作为经济发展的必然产物,截至2016年底,我国高速公路总里程已达13万公里,居世界第一。随着高速公路网的加密,其在煤矿老采空区上方的建设将日趋普遍。如何保障车辆的运行安全将是老采空区上方高速公路建设的关键问题。为此,本文综合采用现场调研,野外勘测,数值模拟、相似材料模拟及理论分析等多种技术手段,围绕着煤矿老采空区高速公路建设安全性评价及其关键技术展开研究,主要取得了以下研究成果:1)将老采空区覆岩视为多元介质耦合的力学结构体,分别采用广义开尔文体、砌体梁结构和复合岩梁结构描述垮落带、断裂带和弯曲带岩体的移动变形。在此基础上,揭示了长壁垮落法开采老采空区的失稳机理,并将老采空区“活化”类型归纳为I类缓慢压缩蠕变型、II类强度衰减蠕变型、I类强度衰减结构失稳型和II类外力干扰结构失稳型四类。2)采用数值模拟方法建立了29个数值模型,揭示了路堤高度、路面刚度、车辆载重及车辆速度四个因素对车辆荷载扰动深度的影响机理。结果表明车辆荷载的扰动深度与路堤高度呈线性关系,与路面刚度、车辆载重及车辆速度呈对数函数关系。采用极差标准化法分析了各影响因素对扰动深度的影响程度,由大到小依次为车辆载重、车辆速度、路面刚度和路堤高度。在上述研究的基础上,结合多元回归分析和叠加原理得到了车辆荷载扰动深度的计算公式,最终给出了车辆动荷载扰动下煤矿老采空区安全深度的计算方法。3)总结归纳了老采空区上方高速公路建设场地稳定性的主要影响因素,采用数值模拟的方法揭示了各影响因素的作用机理,结果表明岩体结构、深厚比和冲积层厚度等因素与建设场地稳定性正相关;地质构造复杂程度、岩石力学强度和重复采动等因素与建设场地稳定性负相关;采动程度与老采空区建设场地稳定性非线性相关,随着采动程度的增加,其稳定性呈现出由高变低再变高的过程。在此基础上,构建了煤矿老采空区上方高速公路建设场地稳定性组合评判模型,融合灰色关联分析、层次分析法和特征向量法给出了组合评判模型中评价要素权重的计算方法,利用散点图法分析了定量因素的隶属函数,最终结合隶属函数和德菲尔法确定了全部评价因子的隶属度。4)为了克服现有预测模型的缺陷,结合老采空区建设场地移动变形“源”的分布特征,基于概率积分法和叠加原理构建了老采空区上方高速公路建设场地移动变形的组合预测模型。结合具体算例对比分析了组合预测模型与现有预测模型的预测效果,结果表明组合预测模型能够全面反映老采空区残余变形“源”导致的建设场地移动变形,可以有效地解决现有预测模型的不足,且该模型能够顾及老采空区“活化”变形的时间效应,使得预测结果更加科学合理。5)给出了煤矿老采空区上方高速公路建设安全性评价研究的一般工作流程,明确了各个工作阶段的具体研究内容及工作方法,总结分析了地球物理勘探及变形监测技术的适用条件,提出了高速公路下伏老采空区的治理对策,最终建议了相关类似课题研究报告中需涵盖的主要内容。6)将本文研究成果应用于武云高速建设的安全性评价,结果表明武云高速建设场地处于基本稳定状态,主要表现为I类缓慢压缩蠕变型和II类强度衰减蠕变型的“活化”类型。预测建设场地的最大残余沉降值为184mm,最大倾斜值为1.2mm/m,最大曲率值为0.02mm/m2,最大水平移动为76mm,最大拉伸变形为1.45mm/m,最大压缩变形为0.76mm/m,但上述变形是大范围、逐渐发生的,不会出现突发性的失稳沉降。综上所述,武云高速下伏老采空区残余变形“源”导致的建设场地移动变形不会对高速公路车辆的运行安全造成威胁。
[Abstract]:In recent years, China's economy has developed rapidly. As an inevitable product of economic development, as of the end of 2016, the total mileage of the highway in China has reached 130 thousand kilometers and ranks first in the world. With the encryption of the highway network, the construction above the old coal mining area in the coal mine will be all over the world. How to ensure the safety of the vehicle's operation will be on the old goaf To solve the key problems of the construction of the freeway, this paper uses a variety of technical means such as field investigation, field survey, numerical simulation, similar material simulation and theoretical analysis, and studies the safety evaluation and key technology of the expressway construction in the old coal mine goaf. The main achievements are as follows: 1) the old goaf The overlying rock is considered as a mechanical structural body coupled with multiple media, with the generalized Kunal style, masonry beam structure and composite rock beam structure describing the movement and deformation of the caving zone, fracture zone and bended rock mass. On this basis, the instability mechanism of the long wall caving method in the mining of the old goaf is revealed, and the "activation" type of the old goaf is summed up into the I class. Slow compressing vermicular form, II class strength attenuating vermicular type, I class intensity attenuated structural instability type and II type external force interference structure instability type four type.2), 29 numerical models are established by numerical simulation method. The influence mechanism of four factors, embankment height, pavement stiffness, vehicle load and vehicle speed on vehicle load disturbance depth, is revealed. It shows that the disturbance depth of vehicle load has a linear relationship with the height of embankment, and has a logarithmic function relationship with road stiffness, vehicle load and vehicle speed. The influence degree of the influence factors on the depth of disturbance is analyzed by the method of extreme standardization. From large to small, the vehicle load, vehicle speed, pavement stiffness and embankment height are in turn. On the basis of the multiple regression analysis and superposition principle, the calculation formula for the depth of the vehicle load disturbance is obtained. Finally, the calculation method of the safety depth of the old mine goaf under the dynamic load disturbance of the vehicle.3 is given. The main factors affecting the stability of the expressway construction site above the old goaf are summarized, and the numerical simulation is adopted. The method reveals the mechanism of the influence factors. The results show that the rock mass structure, the depth ratio and the alluvial thickness are positively related to the stability of the construction site, and the geological structure complexity, the rock mechanics strength and the repeated mining are negatively related to the stability of the construction site, and the mining degree is nonlinear with the stability of the construction site in the old goaf. On the basis of this, the stability combination evaluation model of the expressway construction site above the old coal mine goaf is constructed, and the weight of the evaluation factors in the combined evaluation model is given by combining the grey relational analysis, the analytic hierarchy process and the eigenvector method. The membership function of the quantitative factors is analyzed by the method of scatter plot, and the membership degree.4 of all the evaluation factors is determined with the membership function and the Delphi method. In order to overcome the defects of the existing prediction model, it combines the distribution characteristics of the "source" of the moving deformation of the construction site of the old goaf, and builds on the probability integral method and the superposition principle. Combined with specific examples, the combined prediction model and the existing prediction model are compared and analyzed. The results show that the combined prediction model can fully reflect the moving deformation of the construction site caused by the "source" of the residual deformation in the old goaf, and it can be effective. In order to solve the shortage of the existing prediction model, and the model can take account of the time effect of "activated" deformation in the old goaf, make the prediction result more scientific and reasonable.5), it gives the general working process of the safety evaluation study on the expressway construction above the old coal mine goaf, and clarifies the specific research content and working party of each work stage. The applicable conditions of geophysical exploration and deformation monitoring technology are summarized and analyzed, and the Countermeasures of the old goaf are put forward. Finally, the main contents of the related research report.6) are proposed. The results of this study are applied to the safety evaluation of the high speed construction of Wu Yun. The results show that the Wuhan cloud is built at high speed. The site is in the basic stable state, mainly as the "activation" type of I type slow compressing vermicular type and II class strength attenuation creep type. The maximum residual settlement value of the construction site is 184mm, the maximum tilt value is 1.2mm/m, the maximum curvature value is 0.02mm/m2, the maximum horizontal shift is 76mm, the maximum tensile deformation is 1.45mm/m, and the maximum compression is compressed. The deformation is 0.76mm/m, but the above deformation is in a large range, which will not occur abrupt unstable settlement. In summary, the movement and deformation of the construction site caused by the residual deformation of the old goaf at Wuhan high speed is not a threat to the safety of the motorway vehicles.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U412.22

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