Research On Caving Mechanism And Prevention And Control In Compound Roof Roadway Of Coal Mine

Under the condition of broken rock mass of the compound roof, it’s easy to have a roof caving accident in the process of roadway excavation and maintenance, to study the mechanism of roof caving and put forward the corresponding prevention and control measures have a certain significance. The theoretical analysis, numerical simulation and in-situ observation were used in this paper, the causes and process,prevention and control of caving disaster of compound roof roadway were made a systematic study. The main research conclusions are as follows:(1) Two types of hazard theory was used to analyze the reason for the caving damage of the compound roof roadway, two kinds of hazards of compound roof caving disasters were find, and the interaction relationship between the two hazards was clarified. The reason of the compound roof caving of roadway was further analyze by using bones diagram method.( 2) On the basis of analyzing the compound roof damage types, the decrease causes of bending stiffness and strength of the overall compound roof were analyze by using material mechanics and rock mechanics. The mechanical condition of delimitation buckling in the strata between compound roof was deduced, the caving condition of tensile fracture and shear fracture of compound roof were deduced.(3)Researched on the change process at different fracture forms of compound roof by UDEC software, the results showed that: before the compound roof broke and fell, it produced delimitation under the influence of thin coal seam(weak layers).The flexural fracture of compound roof was under the larger flexural deformation, first, the lower strata cracked in the middle, then, part of the block was caved, last, the rest of strata was fully caved. While, the shear fracture first happened in the lower strata on both sides of compound roof near the two wall, then the entire layer of rock caved at the same time.(4)Researched on these prevention and control measures of the compound roof in roadway roof caving disaster which included the safety technical countermeasures,the safety education countermeasures and the safety management countermeasures.Among them, the safety technical countermeasures that concentrated on the surrounding rock of roadway bolting support technology, the surrounding rock supporting monitoring,the monitoring system of roof rock, the mine personnel positioning system. While, the safety education countermeasures that centralized strengthening all kinds of personnel education training in mine, the safety management countermeasures focused on strengthening the construction of the safety rules and management system, implementation of strict safety management, taking emergency rescue management, and others safety management countermeasures.( 5) Combined with the characteristics of the 701 transport alleys tunneling engineering in the first coal mine of guangxi luocheng, targeted measures based on three aspects which from the safety technical countermeasures, the safety education countermeasures and the safety management countermeasures were put forward.Through the application in the engineering practice, the deformation of the compound roof in this transport alleys tunneling got control significantly, and the safety of the mine roadway excavation and maintenance were ensured.