【作者】 高峰；

【导师】 王连国；

【作者基本信息】 中国矿业大学 ， 工程力学， 2009， 博士

【摘要】 地应力是引起采矿、水利水电、土木建筑及其他各种地下岩土工程变形和破坏的根本作用力。随着我国煤矿开采深度的加大,由地应力引发巷道围岩失稳、冲击地压事故的危险性愈来愈大,现已成为我国矿山亟待深入研究的重大课题。本文综合应用地应力实测技术、地质力学理论、人工神经网络、粒子群优化理论和数值模拟分析手段对地应力分布规律及其对巷道围岩稳定性的影响进行了系统研究,取得了如下创新性研究成果:(1)详细分析了地应力的成因及其影响因素,并以霍州矿区为例,综合运用地质力学理论、地震震源机制解分析和地壳变形GPS测定等方法,进行了矿区地应力场宏观分析。恢复了矿区及邻近区域古地应力场的演变过程,确定了矿区宏观地应力场类型和主压应力轴优势方位分布范围,为验证地应力实测结果的正确性提供了依据。并结合生产实际,系统布置测点,采用应力解除法对整个矿区地应力进行了大规模实测,通过理论分析得到了矿区地应力场的分布规律。(2)运用地质力学基本理论建立了区域地应力场力学计算模型,采用不同形式边界荷载条件进行了弹性力学分析,得到了应力分量的表达式。结合霍州矿区实测数据,以曹村和辛置矿为研究区域,对地应力场进行了有限元多元回归反演分析。计算结果表明,该区地应力场以水平应力为主,由于地质构造和岩性差别等原因,最大主应力变化范围较大,并存在应力相对增高地带。(3)基于霍州矿区大量的地应力实测数据,采用粒子群优化算法训练BP人工神经网络,建立了地应力预测组合神经网络模型(PSO-BP模型),充分利用神经网络的学习能力,建立了实测测点相关参数与对应点地应力之间的非线性映射,并对李雅庄矿和曹村矿不同位置的地应力分布状态进行了成功预测。(4)依据矿区地质资料和实测岩石物理、力学参数,采用数值模拟方法主要就煤道轴向与最大主应力方向夹角α的变化,对巷道顶底板和两帮应力、位移及塑性区范围的影响进行了分析。结果表明最大主应力对巷道围岩稳定性影响显著,得出α> 45°时,巷道围岩应力、位移及塑性区变化幅度突然增大的结论,井下巷道实际破坏情况的统计分析,也证实了上述研究结论。(5)充分考虑地应力对巷道围岩稳定性的影响,提出了基于实测地应力的锚杆支护动态设计方法,并成功地用于高应力碎胀围岩巷道锚杆支护设计,取得了良好的支护效果。更多还原

【Abstract】 Ground stress is the essentially force which arouses deformation and damage in a variety of underground geotechnical engineering. With mining exploration at great depth, the surrounding rock instability and rock burst aroused by ground stress are more and more serious, so, ground stress has become a technical issues needed in-depth study. In this paper, the distribution of ground stress field and its effect on the stability of surrounding rock were studied systematically by using ground stress measurement technology, modern mechanical theory, artificial neural network numerical simulation analysis, and achieves the following research results:(1) The causes and influencing factors of stress field were summarized, and in Huozhou coal area, the stress field was analyzed macroscopically by using the theory of geomechanics, analytical method of earthquake focal mechanism solutions and GPS survey of crustal deformation. In the mining area and adjacent regions, the evolution process of the ancient earth’s crustal stress field was reproduced. In macroscopic view, the type of stress field belongs to horizontal tectonic stress field and the main compressive stress superiority trend is in the NEE～NWW direction, and can provide evidence for the correctness of the stress measured. Combined with the actual production of the mining area, the stress measured points were arranged systematically, and the stress of Huozhou mining area was measured with stress relieving method. Then, the distribution of the whole mining area was obtained by theoretical calculations and mathematical statistics.(2) Based on the theory of geomechanics, the model of regional stress field was established, and the elasticity analysis was carried out with different boundary conditions, and the expressions of stress component were obtained. Combined with the measured data, the Caocun coal mine and Xinzhi coal mine as the study areas, an inverse calculation of the stress field was carried out by using the finite element numerical simulation, and the distribution of stress field was analyzed in great detail. The results show that the stress field relies mainly on horizontal stress, and due to differences in geological structure and lithology and other factors, the range of maximum principal stress is larger, and there are relatively high stress zones.(3) Based on the field measured data of stress field, a combination artificial neural network model (PSO-BP model) of stress field prediction was established, with particle swarm optimization algorithm. Giving full play to the self-learning ability of neural network, the nonlinear mapping between relevant parameters of measuring points and the corresponding stress was established, and got the successful forecasting to the ground stress in Liyazhuang coal mine and Caocun coal mine.(4) Based on the geological data and mechanical parameters of rock by measured, by using FLAC3D, the effect of the angleαbetween the axial location of roadways and direction of maximum principal stress on stress, displacement and plastic zone in roof and floor was analyzed systematically. The results show that the direction of maximum principal stress has a significant effect on the stability of surrounding rock, and whenα> 45°, the stress, displacement and plastic zone in surrounding rock change increased suddenly. The statistical analysis of the actual destruction of underground roadway also confirmed the conclusions of the study.(5) For fully considerating the effect of ground stress on roadway surrounding rock stablity, Dynamic bolt supporting design method based on ground stress measurement is proposed. Based on the results of the study, the bolt support of mining area 10 with expansion broken rock and high stress in Caocun coal mine was designed, and achieved satisfactory supporting effect.更多还原