摘要
西部矿区属于生态本底脆弱的干旱半干旱地区,煤炭资源的高强度开采加剧了矿区生态环境破坏。通过选择合理的开采参数(采高、面长、推进速度)既能保证工作面回采效率,又能减弱煤层开采引起的覆岩变形破坏。为此,本文基于损伤力学构建采动岩体损伤的本构模型,定义了覆岩损伤度指标定量表征开采扰动覆岩三维空间损伤程度。以西部矿区上湾煤矿地质条件为背景,将损伤本构方程嵌入至FLAC3D数值模型,对比分析覆岩损伤度和导水裂隙带的面长和推进速度效应,建立覆岩损伤度与开采参数的定量关系并给出了12401工作面的合理开采参数:采高8.8 m,工作面长度为300 m,推进速度为13.47~20.58 m/d。同时,分析得出了推进速度对顶板损伤特征的影响机制:推进速度增加促使顶板抗拉强度升高,降低覆岩损伤程度。最后,利用不同推进速度情况下的相似模拟以及现场周期来压步距和地表裂隙发育特征实测结果验证了基于覆岩损伤度设计高强度开采参数的合理性。
The fragile ecological environment with arid and semiarid climate in the western mining area of China and high-intensity coal mining activities intensify ecological damage. Choosing reasonable mining parameters(i.e., mining height, panel width, advancing speed) can not only ensure the mining efficiency of a working face, but also weaken the overburden deformation and failures caused by coal seam mining. Therefore, in this paper, the damage constitutive model of mining-induced rock mass is constructed based on damage mechanics, and a damage degree index is defined to quantitatively characterize the damage degree of a mining disturbance overburden in a three-dimensional space. With geological conditions of Shangwan coalmine in the western mining area as the background, numerical models FLAC3D embedded with damage constitutive equation were used to comparatively analyze the panel width effect and advancing speed effect between the overburden damage degree and the height of the water conducted fracture zone. Then, a quantitative correlation was established between the overburden damage degree and mining parameters, and the reasonable mining parameters of working face 12401 was provided: 8.8 m in mining height, 300 m in the working face length, and 13.47–20.58 m/d in advancing speed. Meanwhile, the influence mechanism of advancing speed on the damage characteristics of the roof was obtained: the increase in the advancing speed causes the roof tensile strength to increase, and reduces the damage degree of the overburden rock. The measured results of PWI and ground fissures have verified the validity with the overburden damage degree method to determine high-intensity mining parameters. The rationality of the design of mining parameters based on damage ratio was verified through similar simulation and field measured results of the periodic weighting interval and fracture development under different advancing speeds.
作者
何祥
张村
赵毅鑫
李全生
韩鹏华
陈见行
HE Xiang;ZHANG Cun;ZHAO Yixin;LI Quansheng;HAN Penghua;CHEN Jianhang(State Key Laboratory of Groundwater Protection and Utilization by Coal Mining,National Energy Group Co Ltd,Beijing 100011,China;School of Energy and Mining Engineerings State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2021年第3期439-448,共10页
Journal of Mining & Safety Engineering
基金
北京市自然科学基金项目(8212032)
国家自然科学基金项目(51874312,51904302)
煤炭开采水资源保护与利用国家重点实验室开放基金项目(WPUKFJJ2019-5)。
关键词
损伤本构模型
导水裂隙带
高强度开采
工作面长度
推进速度
damage constitutive model
water conducted fracture zone
high-intensity mining
working face length
advancing speed
