Research On The Overlying Strata Movement Law Of Super-high-water Material Bag-type Filling Mining And Its Control

Super-high-water material bag-type filling mining technology is one of the super-high-water material filling technology, which get the favor of many coal enterprises who mine medium-thick and thick coal seam due to the advantages such as extensive applicability, intuitive filling effects and impregnability of working face water gushing. However, the development of this technology did a lot of restrictions for lacking of enough theoretical foundation on technical parameters and crafts design process. Based on the geological conditions of the filling mining test surface in Chengjiao coal mine as an example, the comprehensive and systematic research on the overlying strata movement law of super-high-water material bag-type filling mining and its control was conducted in this paper, and the research results were used to guide the optimal design of super-high-water material bag-type filling mining technology parameters and process in Chengjiao coal mine. The main results and innovative points are as follows:(1) Through researching on the overlying strata movement law of super-high-water material bag-type filling mining by using similar simulation experiment and numerical simulation, the results show that: In case of super-high-water material bag-type filling mining, the control effect of filling body acting on stope wall rock becomes more obviously, the whole overburden above the mined-out area has maintained continuity and without the caving zone occurred, only a few fractured zone and bending zone existed and the overburden shows a gradual sinking bending process.(2) Deformation mechanism of the filling body and the immediate roof in the condition of super-high-water material bag-type filling mining was analyzed, the breaking condition of immediate roof was given, and some ideas on stope support design was put forward. There must be an ample consideration on game relations between roof subsidence before filing goaf and the distance from roof to support beam during the design process of the support rear top beam.(3) Goaf bag-type filling body losing stability manifests three kinds of forms was put forward, they are collapse, slippage and turnover. Filling body mechanical model was built, the instability conditions of filling body for each form was analyzed and calculated, and the technology to protect the filling body from losing stability was developed. Besides, considering mining height and down-dip angle of working face, the applicability of super-high-water material bag-type filling mining technology was demonstrated.(4) Great effect had been achieved after the research findings used for the key technical parameters and crafts design process of super-high-water material bag-type filling mining in Chengjiao coal mine.This paper has 63 figures, 11 tables and 186 references.