高速公路下伏急倾斜采空区勘察技术及对路基稳定影响研究

发布时间：2018-04-24 03:20

本文选题：路基工程 + 急倾斜采空区　；参考：《长安大学》2015年硕士论文

【摘要】：近年来随着国家经济的高速发展,矿产资源不断开采,在新疆地区形成了大量的急倾斜采空区。随着对基础设施建设的投入不断增大,高速公路建设迅速发展,不可避免的经过急倾斜采空区。因此,对于高速公路下伏急倾斜采空区的变形移动规律研究十分重要。但是,国内外对于下伏急倾斜采空区与高速公路相互作用的研究还较少,理论尚不成熟。为了深入研究下伏急倾斜采空区对高速公路路基及各地层的变形移动规律,依托新疆乌鲁木齐绕城高速公路(东线)急倾斜煤层采空区,采用理论研究、现场勘察、模型试验和数值模拟相结合的方法,分析比选急倾斜采空区勘察技术,并对高速公路下伏急倾斜采空区路基稳定性进行研究,主要研究内容如下:(1)针对新疆乌鲁木齐绕城高速公路急倾斜煤层采空区,通过对既有采空区勘察技术进行比选,在现场采用高密度电法和瞬变电磁法进行勘察,并对物探异常点进行钻孔验证,物探解释结果与钻孔结果吻合良好,得出高密度电法和瞬变电磁法对急倾斜采空区勘察具有良好的适用性。(2)依据相似理论与模型试验,确定大比例尺物理模型试验的相似常数。通过对相似材料的物理力学性能试验,确定可模拟第四系砾石层的相似材料配比为m土:m砂=1:2,ρ=2.0g/cm3,ω=10%,凡士林含量为6%;可模拟中风化砂岩的相似材料配比为m土:m砂=2:1,ρ=2.2g/cm3,ω=10%。(3)根据理论研究和依托工程现场实际情况,选取第一合同段K23+220~K24+70的小窑采空区,通过改变开采厚度和煤层倾角等影响因素,模拟不同试验工况,通过在模型土体中预埋测试元件并定期观测土体竖向位移,利用试验数据绘制路基和地层的位移曲线,得出路基和地层变形移动规律。(4)建立FLAC3D数值模型,监测测点竖向位移,分析数值模拟结果,并通过对模型试验与数值模拟对比分析得出开采厚度、煤层倾角与上覆层厚度对急倾斜煤层采空区路基的稳定影响,确定急倾斜采空区对路基和地层的影响规律。
[Abstract]:In recent years, with the rapid development of national economy, mineral resources have been continuously exploited, and a large number of steep goaf have been formed in Xinjiang. With the increasing investment in infrastructure construction and the rapid development of highway construction, it is inevitable to pass through steep goaf. Therefore, it is very important to study the law of deformation and movement of goaf under freeway. However, there are few researches on the interaction between goaf and highway at home and abroad, and the theory is still immature. In order to deeply study the law of deformation and movement of roadbed and strata of expressway in downhill steep goaf, relying on the goaf of steep coal seam of Urumqi Expressway (East Line) in Xinjiang, theoretical research and field investigation are adopted. Combined with model test and numerical simulation, this paper analyzes the investigation technology of goaf with steep inclination, and studies the stability of roadbed in goaf under freeway. The main research contents are as follows: (1) aiming at the goaf in steep inclined coal seam of Urumqi Expressway in Xinjiang, by comparing and selecting the survey technology of the existing goaf, the high density electric method and transient electromagnetic method are used in the field investigation. The results of geophysical exploration interpretation are in good agreement with the borehole results. It is concluded that the high density electric method and transient electromagnetic method have good applicability for the investigation of steep goaf. The similarity constant of large scale physical model test is determined. By testing the physical and mechanical properties of similar materials, It is determined that the ratio of similar materials that can simulate the Quaternary gravel layer is m: 1: 2, 蟻 = 2.0 g / cm ~ 3, 蠅 ~ (10) = 10 ~ 10 and Vaseline content = 6; the similar material ratio of simulated weathered sandstone is m soil: 1 / m sand, 蟻 ~ (2. 2) g / cm ~ (3), 蠅 10 路3). According to the actual situation of the project, the similar material ratio can be studied and supported according to the actual situation of the project. The small kiln goaf of K23 220~K24 70 in the first contract section is selected. By changing the influence factors such as mining thickness and coal seam inclination, the different test conditions are simulated, and the vertical displacement of the soil is observed periodically by burying the test elements in the model soil. The displacement curve of subgrade and stratum is drawn from test data, and the law of deformation and movement of subgrade and stratum is obtained. The FLAC3D numerical model is established to monitor the vertical displacement of measuring point and analyze the result of numerical simulation. The effects of mining thickness, dip angle of coal seam and thickness of overlying layer on the stability of roadbed in goaf of steeply inclined coal seam are obtained by comparison of model test and numerical simulation, and the influence law of steep goaf on roadbed and stratum is determined.
【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;U416.1

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