基于上限法的深部大断面回采巷道顶板锚索设计方法研究

发布时间：2018-02-26 23:13

  本文关键词： 深部大断面 回采巷道 Hoek-Brown强度准则 上限法 顶板 锚索设计　出处：《岩土力学》2017年08期 　论文类型：期刊论文

【摘要】：针对目前深部大断面回采巷道控制难题和相应的高强锚索控制技术,考虑顶板围岩应力与支护荷载影响,利用Hoek-Brown强度准则及塑性力学中的极限分析上限法,得到了大断面巷道顶板的冒落破坏机制,提出了顶板锚索长度及匹配预紧力的设计方法。基于建立的锚索设计参数影响因素敏感性指标对巷道宽度、岩体重度、围岩应力、岩体抗压强度、抗拉强度、锚索布设间距、顶角锚索布设倾角等因素的影响进行了分析。结合现场实际情况,提出了深部大断面回采巷道围岩控制的工程建议。将此设计方法应用到千米深井赵楼煤矿1305孤岛工作面的运输顺槽顶板锚索参数确定中,有效地控制了围岩变形。研究表明:在高应力大断面回采巷道中,顶板锚索需锚固在稳定岩层中,并施加足够的预紧力,才可有效控制顶板围岩冒落或破坏;顶板锚索所需预紧力随岩体抗拉强度、抗压强度及岩体经验参数A的增大而减小,随巷道宽度、岩体重度、围岩应力、锚索布设间距、顶角锚索布设角度以及岩体经验参数B的增大而增大,其敏感性最高的影响因素为围岩应力。因此,在深部高地应力巷道设计中,需特别重视地应力的影响,采用高强、高延伸率锚索,增设锚索定量让压装置,高阻让压有效释放围岩应力,并通过施加高预紧力或注浆加固等方式来提高围岩完整性,获得较好的围岩控制效果。
[Abstract]:In view of the difficult control problem of deep large section mining roadway and the corresponding control technology of high strength anchor cable, considering the influence of roof surrounding rock stress and supporting load, the Hoek-Brown strength criterion and the upper limit method of limit analysis in plastic mechanics are used. The caving failure mechanism of large section roadway roof is obtained, and the design method of roof anchor cable length and matching pretightening force is put forward. Based on the sensitivity index of influencing factors of anchor cable design parameters, the roadway width, rock mass weight and surrounding rock stress are obtained. The influence of factors such as rock mass compressive strength, tensile strength, spacing between anchor cables, inclination angle of anchor cable placement at the top angle and so on are analyzed. The engineering suggestion of surrounding rock control of deep large section mining roadway is put forward. The design method is applied to determine the parameters of roof anchor cable in 1305 isolated island coal face of Zhaolou coal mine. The study shows that in the roadway with high stress and large section, the roof anchor cable should be anchored in the stable rock stratum and applied enough pretightening force to effectively control the roof wall rock caving or damage. With the increase of tensile strength, compressive strength and experience parameter A of rock mass, the pre-tightening force required by roof anchor cable decreases, and with the width of roadway, the weight of rock mass, the stress of surrounding rock, the spacing of anchor cable, The stress of surrounding rock is the most sensitive factor of the increase of the angle of anchor cable arrangement and the experience parameter B of rock mass. Therefore, in the design of deep roadway with high ground stress, special attention should be paid to the influence of ground stress, and high strength should be adopted. High elongation Anchorage cable, additional cable quantitative pressure device, high resistance pressure effectively release the surrounding rock stress, and through the application of high pretension or grouting reinforcement to improve the integrity of surrounding rock, and obtain a better surrounding rock control effect.
【作者单位】： 济南大学土木建筑学院;山东大学岩土与结构工程研究中心;中国矿业大学深部岩土力学与地下工程国家重点实验室;兖矿集团有限公司;龙口煤电有限公司;
【基金】：国家自然科学基金(No.51674154,No.51474095) 中国博士后科学基金面上资助(No.2016M602144,No.2016M590150) 深部岩土力学与地下工程国家重点实验室开放基金(No.SKLGDUEK1717,No.SKLGDUEK1519) 国家重点研发计划专项资助(No.2016YFC060090X)~~
【分类号】：TD353
，

本文编号：1540092