中文摘要：

位于采煤影响区的高压线、输气输油管道、河道等设施对地表动态移动极为敏感。以甘肃某煤矿在金沙河下开采为背景，通过现场地表移动监测，获得薄冲积层条件下综放开采地表动态移动变形规律。研究表明：薄冲积层下综放开采地表具有下沉移动起始期很短、活跃期较长等特点。地表移动活跃期位于工作面前方110 m至工作面后方400 m范围内，历时185 d，期间地表点下沉量可达到该点总下沉量的90.7%；地表移动剧烈期在工作面后方50 m至150 m范围内，但剧烈扰动时间相对较短，历时约60 d。基于测点下沉曲线为S型分布、下沉速度曲线类似为正态分布特点，建立了考虑开采时间和工作面推进速度因素的地表下沉及下沉速度动态模型，并追踪刻画出地表测点往复式下沉与水平运动的轨迹。薄冲积层下开采，地表裂缝更易平行于工作面走向方向发育，并且随工作面的推进，地表裂缝具有前移和密集区向工作面外侧小范围扩大的时空特征。

英文摘要：

High-voltage transit lines, gas and petroleum pipelines, riverbeds and other facilities located in mining disturbed zones are extremely sensitive to surface dynamic movement. Based on the case of coal mining under Jinsha river in Gansu province, in-site surface movement monitoring is carried out;and the dynamic law of surface subsidence of fully mechanized top coal caving mining under the thin alluvium is obtained. The study shows that the surface subsidence experiences a very short initial period and a longer active period of movement. The active period of surface movement appears in the range from 110 m in front of the working face to 400 m back of working face, which lasts 185 days and results in 90.7%of the total surface subsidence. The severe period of surface subsidence occurs at 50 m to 150 m in the rear of working face;but the severer movement time is relatively short about 60 days. Based on the sinking curves of the measuring point displaying S-shaped distribution, and the sinking rate curves that are similar to normal distribution, the dynamic model of surface subsidence and sinking rate are established with respect to the mining time and advancing rate. The trajectories of ground measuring points are captured showing the back and forth moving characteristics. The fractures on the surface induced by mining under thin alluvium intend to develop parallel to the mining direction. With the working face advancing, the time and space features demonstrate that the surface fractures move forward and the concentration areas expand to the outside of the mining area.