关键词: 留设底煤, 底鼓显现, 弹性地基, 数值模拟, 围岩控制

Abstract: In order to explore the mechanism of floor heave in the roadway of the mining face with reserved bottom coal and the corresponding surrounding rock control technology, a systematic study was conducted on the 402104 track level roadway of Hujiahe Coal Mine using a combination of on-site mine pressure monitoring, theoretical calculation analysis, numerical simulation research, and on-site industrial experiments. The results showed that as the thickness of the reserved bottom coal in the roadway increased, The maximum value and range of vertical upward bending deformation of the beam structure inside the bottom plate have both increased to a certain extent. At the same time, it is more prone to deformation and fracture under higher bending moment forces, resulting in longer block structures and more severe bottom bulges caused by subsequent rotational transport; The increase in the thickness of the reserved bottom coal will lead to a trend of horizontal and vertical displacement of the arch foot position away from the tunnel, while the increase in the cohesion of the reserved bottom coal will cause the horizontal displacement of the arch foot position to be closer to the tunnel, and the vertical displacement to be farther away from the tunnel; As the position of the arch foot gradually moves away from the roadway, the range of plastic deformation and damage to the coal and rock layers inside the floor increases, leading to an increase in the deformation of both sides of the roadway and the floor; By applying bottom angle diagonal anchor cables and anchor rods, the horizontal movement of bottom coal and its shear resistance can be controlled. At the same time, applying bottom plate anchor rods or short anchor cables can control the vertical movement of bottom coal and its strength value. During the on-site industrial test, a surrounding rock control scheme of "high prestressed and strong anchor cables supporting the two sides and bottom corners in a timely manner" was proposed. The overall control effect of the surrounding rock was good, and the maximum bottom heave during the entire tunnel service period did not exceed 0.5 m, and the bottom heave was controlled within a safe range.