摘 要 随着我国国民经济的发展，全国各地都在兴建大量的高等级公路，在修建高等级公路时，不可避免地遇到煤矿采空区工程地质问题。本论文是基于“京福高速公路徐州绕城西段大刘煤矿采空区稳定性分析与研究”项目为背景，在研究该煤矿采空区地质采矿、工程地质特征基础上，分析了高速公路地面及桥墩的沉降观测资料，采用沉陷预计法预测了路中心地表的剩余变形量，同时采用FLAC3D软件模拟该煤矿采空区对高速公路的影响，研究工作得出以下几点主要结论： （1）大刘煤矿采空区地表变形总体表现为宽缓的沉降盆地。沉降观测资料分析表明：高速公路出现了两头小，中间大的沉降变化。沿桥梁方向地表最大沉降量为42.5mm，跨陇海铁路特大桥52#墩最大下沉达到35mm。沉陷预计法计算表明：公路中心地表最大残余沉降为92mm，最大残余水平移动29mm，最大残余倾斜为0.25mm/m；最大残余水平变形为0.21mm/m；最大残余曲率为0.016×10-3/m2。 （2）通过FLAC3D数值模拟分析，在开采后采空区端部应力发生集中，其分布表现为沿着岩层倾斜方向展布的特点。公路中心地表下沉趋势与预计法计算结果较为一致，倾斜岩层在开采后出现上山方向的岩层“上拱”现象，上山方向地表出现了轻微的上升，最大下沉处位置偏向于下山方向。 （3）通过对该煤矿采空区工程地质特征分析，该煤矿采空区仍然存在着“活化”的可能性。结合地表观测资料、沉陷预计计算及FLAC3D数值模拟研究结果的分析，认为：该采空区对高速公路路基影响较小，但对特大桥会产生较大的影响。根据跨陇海铁路特大桥的结构特点，建议对该采空区采取必要的工程治理措施。 论文较深入分析了煤矿采空区上覆岩层应力重新分布和地表移动和变形的特征，并对采空区对公路工程的影响做出评价，提出了大刘煤矿采空区及跨陇海铁路特大桥的治理措施，有一定的研究深度，并对煤炭开采和采空区上部建筑物的保护有实际的应用意义。

ABSTRACT With the rapid growth of the economy in China, a large number of high grade highways are being constructed all over the country. When the freeways were being constructed, the geologic engineering problem of the gob of the coal mine would be fallen across inevitably. Based on the background of the item of “The stability analysis and research of Da Liu mined-out area in the west section of Xu Zhou ring highway of Jing-Fu freeway”，the observation data of the ground and pier subsidence passing through the freeway were analyzed, and the method of prediction subsidence were taken to forecast the residual deformation at the center of the freeway by the researching in the character of geological mining and geological engineering. At the same time, FLAC3D were used to simulate the influence on the freeway causing by the gob of the coal mine. It can concluded from the research work as follow： (1)Above the Da Liu mined-out area, the ground deformation is present as the broad and gentle subsidence basin. The observation data of subsidence shows: the subsidence deformation was small in the two edges while large in the center of the freeway. The maximum subsidence of the ground is 42.5mm; the maximum subsidence of the pier of the super large bridge crossing Long Hai railway reach to 35mm. The subsidence prediction method shows: in the center of the freeway, the maximum residual subsidence was 92mm; the maximum residual horizontal displacement was 29mm; the maximum residual incline was 0.25mm/m; the maximum horizontal residual deformation was 0.21mm/m; the maximum residual curvature was 0.016×10-3/m2. (2)The results of FLAC3D numerical simulation show that the stresses were concentrated in the end region of the mined-out area, and the distribution of the stresses was characterized by changing along the direction of strata’s inclination. The surface subsidence trend was nearly consistent with the results of prediction methods, and the strata on the raising direction moved upward comparing to the original horizon plane. slight ascending was obtained on the surface toward the uphill，the position of the maximum subsidence was lean to the downhill. (3)After the analysis of the engineering geological conditions and surface observation data on the gob of the coal mine, there still have the possibility of activation for the mined-out area. Considering the results both of prediction and FLAC3D numerical simulation, the mined-out area may have less influence to the highway’s roadbed but larger to the super large bridge. Some engineering control measures should be taken according to structural characteristics of super large bridge crossing the Long-hai railway. In this paper, the stresses redistribution, surface movement and deformation characteristics of the overburden rocks in the mined-out area were analyzed deeply, and the evaluation on the influence of the mined-out area was made, and some treating measures and methods were put forward for the Da-liu mined-out area and super large bridge crossing the Long-hai railway. There are certain depth in theoretical research , and the conclusions also have some practical meaning for the coal mining and building protection above the gob.