厚松散层煤层开采地表动态移动变形特征研究

摘要

In order to protect of buildings and control the ground subsidence in the area of covering thick alluvium,based on the measured data of surface movement and deformation above No. 11011 working face of Zhaogu No. 1 Coal Mine,dynamic changes of surface subsidence curve,surface subsidence maximum velocity,surface movement and deformation duration and lagging distance of maximum subsidence velocity were analyzed with mining under thick alluvium.The results indicated that rapid changes in value of surface subsidence appeared, maximum of subsidence velocity was 24.5 mm/d,movement was intense and range of surface subsidence increased obviously.The surface subsidence coefficient expected was more than one in case of full extraction.In the surface movement duration,active phase accounted for 53. 4% the total time,while 91.3% the total subsidence occurred in this period,and decline phase of surface subsidence lasted for a long time,but had a litter subsidence.The working surface of maximum subsidence velocity lag distance was 182 m.The above resluts showed that with the coal mining under thick alluvium,the surface had a several features,for example,subsidence was sensitive to coal caving effect,surface subsidence velocity and coefficient was large,and surface movement was serious,and decline phase of surface subsidence lasted for a long time.%为控制地表沉陷保护地表建筑物，以赵固一矿11011工作面的地表移动变形的实测数据为基础，分析研究了厚松散层条件开采下，地表下沉曲线的动态变化、地表最大下沉速度、地表移动变形持续时间及最大下沉速度滞后情况。结果表明：由于上覆厚松散层土体结构松散、几乎无承载能力，地表下沉量变化较大，地表下沉速度较大，最大值为24.5 mm/d、下沉剧烈且地表下沉的范围增加较明显，在充分采动的情况下，预计其地表下沉系数大于1。在地表移动持续时间中，活跃阶段约占总时间的53.4％，而下沉量占总下沉量的91.3％，因厚松散层土体固结的原因引起的衰退阶段虽然下沉量小但持续时间较长；工作面最大下沉速度滞后距为182 m。上述结果表明厚松散层地区煤层开采，地表呈现受采动影响敏感、下沉速度大、下沉剧烈、下沉系数大和地表移动衰退时间长等特征。