Study On Strata-pressure Behavior And Adaptabilityof Support Of Shallow Thick Seam Sub-level Caving Mining Working Face

Based on the typical geologic hosting condition of shallow thick seam in 6104 sub-level caving mining working face, this thesis analysed the occurrence characteristics and activity law of cover-rock of shallow thick seam, cover-rock’s broken instability characteristics and support resistance, strata-pressure behavior and adaptability of support by combining the theoretical analysis, numerical simulation and field measurement.Firstly, according to the geological conditions and product technology of 6104 working face and occurrence characteristics of 6# coal seam, this thesis analyzed the occurrence characteristics of basement layer and overburden layer, initially identified the ratio of basement and loadings is between 0.56 and. 1.09Secondly, by theoretical calculation, the first weighting length of basic roof is 37.05 m, 31.04 m and 27.25 m, the periodic weighting length of basic roof is 15.13 m, 12.67 m and 11.12 m when ratio of basement and loadings is 1.0, 0.75 and 0.5. By numerical simulation, when the ratio of basement and loadings is reducing or the mining height is increasing, overlying strata influences the working face more severely.Thirdly, according to the results of numerical simulation and field measurement, analyze the “step voussoir beam” structure of shallow thick seam’s sub-level caving mining, define the reasonable support resistance in 6104 working face and determine to choose ZZ13000/22/42 standing shield hydraulic support.Finally, by field measurement, the periodic weighting length in 6104 working face is between 10.8m and 16.8m, the average is 13.88 m. The setting force of hydraulic supports in 6104 working face meet the requirements, working resistance is fully used and the stability of supports is great. So the safety and high efficiency mining is guaranteed.