【作者】 王晖；

【导师】 李智毅；

【作者基本信息】 中国地质大学（北京） ， 岩土工程， 2009， 博士

【摘要】 本文以青兰高速公路邯郸至涉县段沿线北八特采空区为研究对象,通过野外调研和室内测试,研究了采空区地表沉陷特征、影响因素及其上覆松散层的塌陷机理,采用概率积分法计算地表沉陷变形并对其进行了数值模拟,进而运用GIS技术采用图层权重迭加的方法评判了采空区地表塌陷的危险程度。取得以下主要认识:⑴研究区多为小煤窑开采,地表塌陷主要表现为地裂缝和塌陷坑,沉陷盆地仅发育在少数小井周围,塌陷坑大都由地裂缝发展演化形成。⑵研究区地表塌陷的主要原因是由于采深较浅,冒落带和裂缝带可直达地表,上覆黄土松散层具有一定的结构强度,致使地表塌陷存在滞后现象。松散层黄土的垂直节理先形成拉裂缝,而后在地表水流作用下发生潜蚀、淘蚀,裂缝进一步扩大延伸,进而形成塌陷坑。研究区松散层土体微结构松散,孔隙率高,胶结力弱,粒间表现为直接接触关系,颗粒间及周围胶结物较少,遇水后碳酸盐类矿物易发生溶解,导致黄土结构强度丧失,继而引起黄土塌陷下沉。这是本文主要创新之处。⑶概率积分法计算地表沉陷变形与数值模拟结果表明,北八特地区最大沉陷量可达6353.42mm,最大剩余沉陷量可达953.01mm。沉陷变形预计总量及剩余量均超过我国现今高速公路路基容许值。两种方法计算结果相近,说明采用FLAG3D对采空区进行地表沉陷模拟是可行的。⑷地表塌陷危险性评判结果表明,除陷落柱范围以外,研究区内高速公路沿线及两侧区段基本处于危险与较危险区域范围内,高速公路在建设前应采取适当措施对采空区进行处理。⑸本文研究成果可进一步推广至具有相同或相似工程地质条件的采空区乃至整个黄土地区下伏煤矿采空区地表沉陷量的预测,对于今后我国高等级公路建设中跨越采空区的地基稳定性评价、处治方案设计,以及在已建设的高等级公路下伏煤层回采等均具有较好的理论指导意义和巨大的经济效益。更多还原

【Abstract】 In this paper, which took the Bei Bate coal mined-out area along Qing-lan highway from Handan to Shexian as the object of study, through field investigation and indoor tests, we studied the characteristics , affecting factors and collapse mechanism of the ground subsidence in the mined-out area, calculated the deformation of surface subsidence using probability-integral method and its numerical simulation. Then, using GIS technology ,by the mothed of superimpose of a layer of the right ,we judged the level of risk of ground subsidence in the mined-out area. Mainly obtained following research and the understanding:⑴In the study area of this paper, minings are mostly in the small coal mines. Types of surface subsidence is mainly cracks and collapse pits, which inclode a few sink basin around a few small well. The collapse pits in the area were mostly developed from the ground cracks .⑵The causing factor of the surface subsidence in the study area is mainly due to the followings: mining depth is shallower, caving zone and fracture zone can reach the surface, overlying a loose layer of loess has some structural strength, which resulting the lag phenomenon of the surface subsidence, after the crack from vertical joints was formed in the loose layer of loess, it would be enlarged ang extended by the submarine erosion and corrosion under the action of surface water occurred in cracks, and thus it would form the collapse pit. The characteristics of micro-structure of the loose layer soil in the area is loose, high porosity, and weakly cementation, direct contact and less contact between grains, the dissolution of carbonate minerals-prone with water, which can result in the loss of the loess structural strength , followed by loess collapse caused by subsidence. These are the main innovation of this paper.⑶According to the calculation of the surface subsidence deformation by the method of the probability integration method and numerical simulation,it shows that the largest volume of the surface subsidence in the Bei Bate region can add up to 6353.42mm, and the largest amount of residual subsidence up to 953.01mm. The Subsidence deformation and residual volume is expected to total more than the value of highway embankment allowed in China. The calculation results from the two methods were similar, which can show that the method of numerical simulation by FLAG3D is feasible to indicate the surface subsidence of the mined-out areas.⑷According to the risk evaluation results of the surface subsidence in the the study area along the highway and both sides of the section, it can show that, in addition to the scope of the fall columns, there will be at risk and the more dangerous areas and should be taken appropriate measures to deal with mined-out area .⑸The achievement of this study can be further spreaded to the same or similar engineering geological conditions of the mined-out area and the whole loess region underlying coal mining area to predict the amount of the surface subsidence deformation , which can contribute theoretical guidance and tremendous economic benefits in the field of ground stability evaluation ,design and treatment for the construction of high-grade highways which across the mined-out area, and for the underlying coal mining under the highway.更多还原