深部采场无底柱深孔后退式开采围岩力学响应特征

 运用Surpac 和FLAC^3D组合建模技术建立深部矿区三维数值分析模型,基于多元线性回归分析方法模拟反演出深部区域现存地应力场,采用模型重构方法获取了采场及周边的局部地应力分布规律.研究某采场利用无底柱深孔后退式采矿方法开采的围岩力学响应特征,结果表明:1)采场围岩的最大拉应力为0.40 MPa,最大水平位移为28.2 mm,出现在采场 Y 向中轴线附近南帮位置,最大垂直位移为27.43 mm,出现在 Y 向中轴线附近顶板位置,采场围岩发生了一定范围的塑性破坏;2)采场 Y 向中轴线附近位置顶板位移较大,应加强地压监测;采场东头由于受到爆破积累损伤的影响,在对东头侧向崩矿时,要适当调整孔网参数;采场南帮临近区域要增加预裂孔、减小单孔装药量及每段起爆药量,防止爆破超挖矿柱,影响整个盘区的稳定.

Characteristics of mechanical response of surrounding rocks in deep hole pillarless retreating mining at deep stope

A three-dimensional numerical analysis model was developed using the complex geological modeling techniques, Surpac and FLAC^3D. The initial geo-stress field was obtained by using multiple linear regression method, and the distribution law of in-situ geo- stress field around the stope was obtained by geometric cross- scale model- building technology. On the basis of that, the characteristics of mechanical response of surrounding rocks in deep hole pillarless retreating mining at deep stope were studied. The results showed that: 1) The maximum tensile stress of 0.40 MPa and the maximum horizontal displacement of 28.2 mm were observed at south side of the stope near the Y-central axis. The maximum vertical stress of surrounding rocks was found to be significant at stope roof near the Y-central axis with the maximum value of 27.43 mm. Plastic failure occurred in these corresponding regions. 2) Field monitoring and security measures need to be strengthened near the Y-central axis. The hole net parameter needs to be adjusted in eastward lateral caving due to accumulated damage of blasting. In the south side of the stope, it is necessary to increase presplit holes and reduce single hole explosive load and the initiation dose of each segment to prevent the overbreak of the pillar to affect the stability of the entire extent.