| Detailed researches are implemented to structure and control of surrounding rock in mining steep seams using horizontal section top-coal caving in this paper. Some structures are found in surrounding rock after mining steep seams. That is to say, it has structure effect. Instability of structures will affect strata behavior and result in destruction of surrounding rock. The important aspects of surrounding rock control are roof control and decreasing surface subsidence. Simulating model test is firstly carried to manifest there must have certain structure in roof strata about roof research. Secondly, discretion formula of roof destruction is obtained by simplifying roof strata to elastic thin board. By contrasting with weighting observation data, the conclusion that roof strata have large-small structures is demonstrated. The big structure is a uninstalled arch spanning gob areas with unequal height. Its range is a dynamic enlargement process from balance to instability and again to stability. The small structure is a hinge structure protected by big structures. The mechanical model and math expressions of large-small structures are also gained. Furthermore, some factors of affecting structure stability are also studied. Finally, using finite element calculation, the correctness of above conclusions is demonstrated. Fragmentation mechanism and arch destruction effect of top-coal are revealed about top-coal research. The mechanical model of arch of spanning strata is established. The character and instability mechanism of spanning arch are also revealed. Roof and surface are two important factors to the control of surrounding rock. By analyzing subsidence mechanism and action mechanism filling sienna, the way of decreasing roof destruction and surface subsidence is obtained. Generally, this paper gives certain analysis to structure and control of surrounding rock in studying horizontal section top-coal caving. The research has positive meaning to steep seams.
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