School of Civil Engineering, North China University of Technology

为研究采空区刚度对采场围岩稳定性的影响,采用PHASE2D有限元软件建立3种采空区刚度数值模型,其中模型Ⅰ的采空区刚度最大,模型Ⅱ最小,模型Ⅲ居中,研究了工作面前方煤体塑性区的发展规律、直接顶下沉量、覆岩垂直位移和工作面支承压力变化规律。研究结果表明,当工作面推进150m时,3种采空区刚度下的工作面前方煤体塑性区宽度分别为2.08mm、3.56mm和3.13mm,采空区刚度越大,工作面煤体塑性区宽度越小;模型Ⅰ、Ⅱ和Ⅲ的直接顶最大下沉量分别为38.8mm、106.6mm和96.8mm,覆岩垂直位移最大值为44.9mm、148.3mm和137.4mm;随着工作面推进,工作面前方支承压力增高系数先增大后稳定,模型Ⅰ、Ⅱ和Ⅲ支承压力增高系数峰值依次为2.1、3.7和3.4。分析认为,增大采空区刚度有利于降低工作面支承压力,提高采场围岩稳定性。

In order to investigate the influence of the stiffness of goaf on the stability of surrounding rock in mining area,three numerical models with different goaf stiffness were constructed using PHASE 2D finite element software. Model Ⅰ hadthe highest goaf stiffness, Model Ⅱ the lowest, and Model Ⅲ the medium. The development of the plastic zone in front of theworking face, the vertical displacement of the immediate roof and the overlying strata, and the abutment pressure of the mining face were studied. The results showed that: when the mining face advanced 150 m, the widths of the plastic zones in frontof the mining face for Models Ⅰ, Ⅱ, and Ⅲ were 2. 08 mm, 3. 56 mm and 3. 13 mm, respectively. Hence, the greater goafstiffness, the smaller plastic zone in front of face. The maximum vertical displacement of the immediate roof were 38. 8 mm,106. 6 mm, and 96. 8 mm, respectively, while the maximum vertical displacement of the overlying strata were 44. 85 mm,148. 25 mm, and 137. 36 mm. As the mining face advanced, the abutment pressure coefficient in front of the face increasedfirst before it is stabilized. The peak values were 2. 1, 3. 7, and 3. 4 for Models Ⅰ, Ⅱ, and Ⅲ, respectively. As a result, increasing the goaf stiffness is beneficial to improving the stability of the surrounding rock in mining areas.

国家自然科学基金资助项目(52004010);北京市属高等学校优秀青年人才培育计划项目(BPHR202203036);贵州省科技计划项目(黔科合支撑〔2023〕一般122)