振动载荷对青砂岩冲击裂纹扩展及能量利用效率的影响  

Influence of vibration loading on impact crack propagation and energy utilization efficiency in green sandstone

作　　者：赵环帅 潘永泰[1,2] 余超 乔鑫[1,2] 曹行健 牛学超 ZHAO Huanshuai;PAN Yongtai;YU Chao;QIAO Xin;CAO Xingjian;NIU Xuechao(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Engineering Research Center for Mining and Urban Solid Waste Recycling,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Architecture and Surveying Engineering,Beijing Polytechnic College,Beijing 100042,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]中国矿业大学(北京)矿山与城市固废资源化工程研究中心,北京100083 [3]北京工业职业技术学院建筑与测绘工程学院,北京100042

出　　处：《清华大学学报（自然科学版）》2024年第12期2155-2165,共11页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金面上项目(52074308)。

摘　　要：在岩石破碎过程中,外部加载方式是影响岩石力学特性与破裂行为的重要因素。振动、冲击是最常用的两种加载方式,但目前研究主要集中于单一加载方式,关于振动载荷对岩石在冲击过程中破裂特征的影响研究较少。该文结合室内试验与细观参数标定,建立青砂岩宏-细观力学响应关系,对比分析了冲击、振动冲击复合加载下的裂纹扩展及能量利用效率。研究结果表明:在相同冲击速度作用下,增加振动频率或振幅,青砂岩裂纹数量与能量利用效率的增幅总体上均呈现出增大趋势。两种加载方式下,随着冲击速度的增大,青砂岩裂纹最大数量均呈接近直线形增长,拉伸裂纹的数量居多,裂纹的分布均呈X状共轭斜面特征,但振动冲击复合加载下裂纹增长速度相对较大;建立了振动载荷下裂纹增加的数量与冲击速度的定量关系。振动载荷对最大能量利用效率的增幅呈现出先快速增加后减小的趋势,最大增幅为0.725%。该研究初步探索了振动载荷对青砂岩冲击裂纹扩展及能量利用效率的影响,可为岩石破碎工艺参数的合理选择提供参考。[Objective] In rock-crushing processes,external loading methods are important factors affecting the mechanical properties and fracture behavior of rocks.Among these loading methods,vibration and impact methods are the most common ones.However,previous research has mainly focused on macroscopic failure features and energy dissipation properties under the singular loading of vibration or impact.Research on the composite loading of vibration and impact is relatively scarce,and few studies have investigated the influence of vibration loading on the microscopic fracture characteristics and energy evolution during rock impacts.In particular,quantitative characterization studies are lacking.The research on the influence of vibration loading on the propagation of impact cracks and the energy utilization efficiency in rocks has significant academic and engineering applications to fully adapt to the needs of modern mine construction and high efficiency,energy saving,and green production.[Methods] The quasi-brittle green sandstone material,commonly used in rock-crushing operations,was taken as the research object.The macro/micromechanical response relationship of green sandstone was established by integrating indoor experiments with microscopic parameter calibration.The parallel bonding model was adopted,and two loading methods — impact and composite loading of vibration and impact — were compared and analyzed to investigate the influence of vibration loading on the propagation of impact cracks and the energy utilization efficiency in the failure process of green sandstone.The analysis was conducted using the particle flow code(PFC).[Results] The research results indicate that under the same impact velocity,increasing the frequency or amplitude of vibration leads to an increasing trend in the number of cracks in green sandstone.Under the two loading methods,the maximum number of cracks in green sandstone shows a nearly linear increase as the impact velocity increases,with the majority being tensile cracks.The distributi

关 键 词：青砂岩 振动载荷 裂纹扩展 断裂能 

分 类 号：TU452[建筑科学—岩土工程]