关键词: 近浅埋煤层, 断裂步距, 大周期来压, 小周期来压

Abstract: To study roof movement law of near shallow seam, a deep multi-bases displacement monitoring device is adopted to probe roof movement behaviors of 20307 near shallow working face in Gaojialiang Mine. Roof breaking model of near shallow seam is built, and the initial and cycle fracture of key strata are simplified to clamped and trilateral clamped and one-side uniform loaded rectangular plate respectively. The fracture length of key strata is derived using plastic limit analysis theorem and the correction method of fracture length of inferior key strata is put forward. Compared with ground pressure observation, the average error is 7.03%, and the large weightings gain from theoretical calculations and ground pressure observation are almost the same. This research provides a theoretical basis for roof control design of near shallow seam.

Key words: near shallow seam, fracture length, large weighting, small weighting