Technology of Floor Heave Prevention and Control in Fully-Mechanized Thick Seam Top Coal Caving Mining Face with High Intensity Mining

ZHANG Ke-xue; MA Zhen-qian; YANG Ying-ming; MA Chang-le; JIANG Cong; LI Yan-wei

doi:10.13199/j.cnki.cst.2014.11.010

Abstract：In order to improve mining efficiency of a fully-mechanized top coal caving mining face in thick seam,the similar simulation, numerical analysis,site monitoring and measuring and other means were applied to analyze obvious mine strata pressure behavior,serious gateway floor heave and other mechanism faced by a high intensity mining of a fully-mechanized top coal caving mining face.According to the roof failure features of the overburden strata and the coal and rock movement law,a study was conducted on the mine strata pressure behavior features,gateway floor heave deformation features and others.The results showed that under the mining influences of the gateway two sidewall,the floor strata of the mining gateway had a zero displacement isoline and a zero strain isoline,the max depth of the zero dis-placement point in the floor was determined as 1.9 m and the max depth of the zero strain point was 3.4 m.Thus the key technology of the gateway floor heave control for the high intensity mining of the fully-mechanized top coal caving mining face was provided.The key technol-ogy would apply through anchors,additional high strength yield bolts and others to enhance the support of the two sidewalls and apply a 2. 4 m long hydraulic swelling bolt to fix a bolt end in a tensile strain compressed zone of floor.An active anchoring force of the bolt and an ad-ditional anchoring force of the bolt provided by the downward compression of the surrounding rock at the anchoring end were applied to in-crease a flexural rigidity of the floor strata and to limit the floor heave.Meanwhile,the bolt at the floor corner of the floor should be set with a 45° angle to limit a high shearing stress role within the scope.