| Loess gully region that the surface is cutted broken, gully development, low vegetation cover, seriously soil and water loss. It is a special kind of topography in China, mainly distributed in the Yellow River. A large number of surface cracks were caused by mining in the area, which often induced other mining damages such as landslides, collapses and landslides. As the particularity of overlying rocks and topography, the normal laws of surface movement and deformation are coverd up, meanwhile, surface damage is exacerbated by valley. Therefore, it is of great significance to study the characteristics of surface movement and deformation as well as mechanism of surface crack.A lot of subsidence damage in loess gully region show that the main types of mining damage are stepped cracks, collapse and landslides while the thick loess and gully topography is major aggravating factor in mining disaster. Observation station of surface movement is layouted in 302,303 face of Huangling mine to analyze and valculate surface movement angle, subsidence parameters and dynamic movement and deformation parameters of surface. Comprehensive analysis was made on mining subsidence data of Huangling and Weibei which belong to the loess gully region shows that coupling effect between loess and gully topography on surface resulted in extension of surface horizontal movement, larger subsidence factor and displacement factor. With the ratio of loess layer thickness h: mining depth H to characterize the movement and deformation, the estimating formula of largest horizontal movement and deformation were obtained which can adapt to loess gully region. By means of numerical simulation the mechanism of surface cracks is analysised.Combination of subsidence damage characteristics and analysis of observational data, the law of mining subsidence in loess gully region is given. It provides theoretical foundation for further study on contron of subsidence damage in the area.
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