双巷布置下回采巷道采动破坏规律数值模拟研究

Numerical simulation study on mining−induced damage law of mining roadway under double−lane layout

  • 摘要: 针对双巷布置中留巷受采动影响的变形破坏问题,以某矿 502 工作面回风巷为背景,采用 FLAC3D 模拟其掘进与回采阶段的围岩变形及应力分布,揭示采动扰动下的动态响应规律。结果表明:回采工作面前方 30 m、后方 100 m 范围内均存在应力集中,煤柱侧应力峰值达− 15.5 MPa,显著高于非煤柱侧,且工作面后方 100 m 为应力剧烈变化核心区。采动对留巷的应力扰动呈动态演化,垂直与水平应力变化趋势一致,随推进长度呈“周期性稳定−突变”特征(推进 0~300 m 时应力峰值每 100 m 增 1.2 MPa,300 m 后趋于稳定)。随着动压对围岩的影响逐渐加深,围岩变形逐步进入塑性阶段,最大主应力超限导致破坏范围扩展;主应力偏转引发顶、底、帮变形不协调,顶底板破坏呈非对称分布(推进 500 m 时顶板最大变形为底板的 1.33 倍,右帮变形为左帮的 0.44 倍),且工作面及切眼附近变形最显著(顶底板最大移近量达 120 mm,两帮达 90 mm)。基于上述规律,讨论了双巷布置下回采巷道在不同地质条件和巷道几何形状下的适应性、应用限制、推广校准要求及具体防治措施,进一步明确本研究方法的工程实用性与推广价值。研究系统阐明双巷布置下留巷受多工作面动态采动的耦合影响机制,为类似条件下巷道稳定性控制提供定量依据。

     

    Abstract: To address the deformation and failure issues of retained roadways in the dual−winding layout induced by mining activities, this study took the return airway of the 502 working face in a certain mine as the research background. FLAC3D was employed to simulate the rock deformation and stress distribution of the surrounding rock during the excavation and mining stages, thereby revealing the dynamic response laws under the influence of mining disturbances. The results show that stress concentration occurs within 30 meters in front of and 100 meters behind the mining face. The peak stress on the coal pillar side reaches −15.5 MPa, which is significantly higher than that on the non−coal pillar side, and the 100−meter area behind the working face is the core zone with intense stress variation. The stress disturbance of mining on the retained roadway presents a dynamic evolution, and the variation trends of vertical and horizontal stresses are consistent. The stress fluctuates periodically and stabilizes after the working face advances 300 meters (within the first 300 meters of advancement, the peak stress increases by 1.2 MPa every 100 meters, and remains stable thereafter).As the influence of dynamic pressure on the surrounding rock gradually deepens, the deformation of the surrounding rock gradually enters the plastic stage. When the maximum principal stress exceeds the limit, the failure range expands; the deviation of principal stress triggers inconsistent deformation of the roof, floor, and sidewalls. The failure of the roof and floor shows an asymmetric distribution (at 500 meters, the maximum deformation of the roof is 1.33 times that of the floor, and the deformation of the right sidewall is 0.44 times that of the left sidewall), and the deformation near the working face and the drift is the most significant (the maximum displacement of the roof and floor reaches 120 mm, and that of the two sidewalls reaches 90 mm). Based on the above laws, the adaptability, application limitations, promotion calibration requirements, and specific prevention measures of mining roadways in the dual−winding layout under different geological conditions and roadway geometric shapes were discussed, which further clarifies the engineering practicality and promotion value of the research method. This study systematically clarifies the coupling influence mechanism of retained roadways in the dual−winding layout under the dynamic mining activities of multiple working faces, providing a quantitative basis for the stability control of roadways under similar conditions.

     

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