Applicability Study Of Two-leg Shield Support About Fully Mechanized Caving Face In The Dongtan Mine

According to the main problems of four-leg chock-shield caving coal hydraulicsupport which is being widely used, the two-leg shield caving coal support is putforward. On the basis of field measurement, theoretical analysis and numericalsimulation, this paper does the research on applicability of two-leg shield support withequipments, geological conditions and mining process in fully mechanized caving face.Firstly, it analyses the geological data and production technology condition of DongtanMine1303caving face. Then, it studies on the strata-pressure behavior law of two-legshield support caving coal face. The result shows that there is relationship betweendynamic load coefficient and working resistance in non-weighting period, and therelationship is a conic. Next, it analyses the control effect of support to top coal stability,which indicates that the key to control top coal stability of two-leg support has two parts.On the one hand, this kind of support can adjust to dynamic change of pressure whencaving top coal, and provide higher working resistant. On the other hand, it can providesactive and higher horizontal stress to reduce tensile stress in the end face area, whichcan hold the integrity of top coal. At the last, the paper analyses coal caving effect andprocess parameters. By the research above, the conclusion would enrich the applicabilityresearch of caving hydraulic support, and be useful to some similar coal areas with thesame occurrence condition of coal seams including Dongtan Mine.