关键词: 软弱夹层, 巷道底板, 夹层位置, 夹层个数

Abstract: In order to analyze the influence of floor weak interlayer on floor heave in roadway surrounding, eight models based on different position and number of weak interlayer in the floor have been constructed by combining numerical simulation with theoretical calculations. The influence of interlayer on floor heave deformation, plastic area and stress distribution law has been analyzed. The simulation results show that: 1) The volume of roadway floor heave increases gradually with the increase of interlayer number, and when there are 3 interlayers in the coal floor, the volume of roadway floor heave is 1.88 times than the volume without interlayer, while when there are the same number of interlayer, shallow part and deep interlayer have greater influence on the floor heave in deep level than middle-deep interlayer. 2) The strength of floor surrounding rock is weakened by partial shallow interlayer, which causes the increase in the tensile failure depth of floor. Unbalance energy is absorbed by middle- deep and deep interlayer, so that the original rocks area form in the vicinity of the level of surrounding rock. Deep interlayer can decrease plastic area compared with shallow part interlayer. 3) The stress concentration zone decreases gradually in floor surrounding rock with increase of interlayer number and distance between interlayer and surface of roadway floor. 4) Stress uniform distribution is separated by interlayer, and stress concentration near deep interlayer, in a manner, are formed. According to the simulation results, it is concluded that the roadway with weak interlayer in the floor must be reinforced in order to control floor heave.

Key words: weak interlayer, roadway floor, interlayer location, interlayer number