摘要
随着地下工程领域的持续拓展与深化,以冲击地压为典型代表的动力灾害问题日益凸显,对工程安全与稳定构成了严峻挑战。鉴于巷道周边岩体在开采活动前即已承受复杂的三向应力状态,深入探索并揭示其三维动态力学行为特性,对于有效预防与减轻冲击灾害具有很大价值。锚注联合支护是地下工程裂隙围岩动力灾害防控的常用支护方式,但锚注支护设计多以经验为主,亟须研究冲击荷载作用下锚注加固裂隙岩体抗冲特性,为破裂围岩冲击地压巷道锚注加固抗冲设计提供科学依据。采用SHPB冲击试验系统,考虑应力和应变率的影响,对锚注加固单裂隙红砂岩试样进行不同围压和冲击速度加载条件下的动态力学特性研究工作。在此过程中,详细讨论了试样的应力-应变曲线特征、动强度表现、动变形行为、耗能特性以及破坏模式。研究结果表明:不同围压和冲击速度加载条件下试样的应力应变曲线具有明显的应变硬化和塑性流动,随着围压和冲击速度的增大,试样动峰值强度均呈现增大的趋势;动峰值应变随着冲击速度的增大而增大,随着围压的增大而减小,动割线模量则与之相反;通过三维曲面拟合描述耗散率随围压以及冲击速度的变化特征,得到近似满足带常数项的三维曲面预测模型,为预测和控制岩体的能量耗散过程提供有力的数值支撑。
With the continuous expansion and deepening of the field of underground engineering,the dynamic disaster,with rock burst as its typical representative,becomes increasingly prominent,posing a severe challenge to engineering safety and stability.Since the rock mass around the roadway has been subjected to complex triaxial stress state before mining activities,it is invaluable to explore and reveal its three-dimensional dynamic mechanical behavior characteristics for effective prevention and mitigation of impact disasters.Bolt-grouting combined support is a commonly used support approach for the prevention and control of dynamic disasters in fractured surrounding rocks in underground engineering.However,the design of bolt-grouting support is mostly based on experience,and there is an urgent need to study the impact resistance characteristics of bolt-grouting reinforced fractured rock masses under impact loads,providing a scientific basis for the design of impact-resistant bolt-grouting reinforcement for roadways in fractured surrounding rocks prone to rock burst.In this paper,the Split Hopkinson Pressure Bar(SHPB)impact test system was adopted,taking into account the influence of stress and strain rate,to study the dynamic mechanical properties of bolt-grouting reinforced single-fractured red sandstone masses under varying confining pressures and impact velocities.In this process,the stress-strain curve,dynamic strength,dynamic deformation behavior,energy dissipation characteristics,and failure modes of the samples were discussed in detail.The results are drawn as follows.Under different confining pressures and impact velocities,the stress-strain curves of the samples exhibit distinct strain hardening and plastic flow characteristics.As the confining pressure and impact velocity increase,the dynamic peak strength of the samples tends to increase.The dynamic peak strain rises with the increase of impact velocity but decreases with the increase of confining pressure,while the dynamic secant modulus behaves inversely.The variation characteristics of the dissipation rate with confining pressure and impact velocity are described by three-dimensional surface fitting,and a three-dimensional surface prediction model with constant term is obtained,which can provide a strong numerical support for predicting and controlling the energy dissipation process of rock mass.
作者
杨大方
陈舒凯
李佳赛
冯文林
高帅
YANG Dafang;CHEN Shukai;LI Jiasai;FENG Wenlin;GAO Shuai(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454000,China;School of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;School of Civil Environment,Harbin Institute of Technology,Shenzhen 518055,China)
出处
《铁道科学与工程学报》
北大核心
2025年第5期2180-2190,共11页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(52178388)
河南省科技攻关项目(232102320023)
河南理工大学博士基金资助项目(B2019-35)。
关键词
围压
冲击荷载
动态力学特性
锚注加固
能量耗散
confining pressure
impact ground pressure
dynamic mechanical properties
bolt-grouting reinforcement
energy dissipation
