摘要
对李家壕煤矿矸石山进行实地勘察选点,对不同排弃时间段的矸石岩体进行原位剪切试验和室内大型剪切试验,分析了相应试验的矸石岩体剪切应力-剪切位移曲线规律,计算了不同压力级别下的峰值抗剪强度,并结合Hoek-Brown岩体强度准则分析黏聚力和内摩擦角试验值。结果表明:矸石的排弃时间越长,外部载荷影响次数越多,所处矸石山边坡堆积层位高度越低,矸石块体的胶结情况就越好,则矸石岩体滞后达到峰值强度,其抗剪强度就越大;原位剪切试验中矸石岩体呈剪切型摩擦剪切,与大型剪切试验的矸石块体剪切应力-剪切位移曲线都呈一定的线性规律,表现出峰值强度前阶段,随着剪应力的增加,以明显的弹性剪切变形为主;矸石原位剪切试验的黏聚力和内摩擦角都比大型剪切试验值大,Hoek-Brown岩体强度准则估计的黏聚力值都比试验值偏大,而内摩擦角估计值和试验值较为接近。该成果可为今后研究矸石岩体抗剪特性及矸石山边坡稳定性分析提供参考。
After field survey of waste dump in Lijiahao Coal Mine,in-situ shear test and indoor large shear test are carried out on waste rock mass of different abandoned time,the shear stress and shear displacement are analyzed,the peak shear stress under different stress level of shear strength is calculated,and combining with the Hoek-Brown criterion of rock mass strength,cohesion and angle of internal friction are discussed. The results show that,the longer the abandoned time is,the more it is influenced by the external load;and the lower the level of accumulation layer in the waste dump slope is,the better the cementation it has,and the waste rock mass lags to reach the peak strength,thus getting greater shear strength. In the in-situ shear test,the shear type is frictional shear,and the shear stress-shear displacement curve in large shear test are of a certain linear rule,showing that,in the pre-peak strength stage,as the shear stress increases,obvious elastic shear deformation dominates. The waste’s cohesiveness and angle of internal friction of in situ shear test are larger than those in large shear test and the cohesiveness value estimated by the Hoek-Brown criterion of rock mass strength is larger than the experimental value,while the estimated value of angle of internal friction is closer to the experimental value. The study can provide reference for future study of the shear properties of waste rock mass and the stability analysis of waste dump slope.
作者
贺艳军
李建华
陈涛
韩流
HE Yan-jun;LI Jian-hua;CHEN Tao;HAN Liu(Inner Mongolia Science and Technology Mining Research Institute,Baotou 014010,China;Lijiahao Mine,Shenhua Baotou Energy Corporation Ltd.,Ordos 017000,China;School of Mines,China University of Mining and Technology,Jiangsu 221116,China)
出处
《煤炭工程》
北大核心
2020年第11期137-143,共7页
Coal Engineering
基金
国家重点研发计划项目(2016YFC0501103)
国家自然科学基金青年基金项目(51804298)。
