摘要
针对寒区露天矿边坡岩体在冻融环境下的损伤劣化问题,以内蒙古某典型露天矿边坡出露的多种板岩为研究对象,开展了冻融循环、单轴压缩、纵波波速测试等多项室内试验。试验模拟自然环境下的冻融过程,设置不同循环次数,系统分析冻融作用对板岩质量损失、纵波速度、力学参数等物理力学性质的影响规律。在获得岩体主要物性参数演化特征的基础上,构建了考虑冻融循环次数影响的损伤演化方程,并基于数值模拟方法对不同冻融阶段板岩的损伤扩展过程与破坏模式进行了深入分析。试验结果表明:随着冻融循环次数的增加,板岩质量逐步减轻,纵波传播速度显著降低,单轴抗压强度和弹性模量持续衰减,整体呈现出明显的劣化趋势。弹性模量与冻融循环次数之间符合负指数衰减关系,在经过20次冻融循环后,弹性模量下降幅度超过50%,表明冻融过程对岩体结构完整性具有显著削弱作用。在微观结构上,板岩内部初始微裂隙逐渐扩展并连通,损伤区域增大,局部裂纹发展为可识别的宏观裂缝;随着冻融循环次数的累积,板岩的破坏模式也由早期的单一贯通破裂面向多条非贯通裂缝并存的复杂破坏形态转变,破裂路径趋于分散化和非线性。数值模拟结果进一步表明,冻融损伤不仅降低了岩体整体承载能力,也促使损伤区集中分布于试样中部与两端结合部位,损伤场演化与应力集中区高度吻合。由此揭示了冻融循环对板岩强度和结构演化机制的耦合作用特征。
Aiming at the problem of damage and deterioration of slate on the slopes of open-pit mines in cold regions under freezethaw conditions,various types of slate samples from a typical open-pit mine in Inner Mongolia were subjected to laboratory tests,including freeze-thaw cycling,uniaxial compression,and P-wave velocity measurements.The experiment simulated the freeze-thaw process in a natural environment,set different cycle times,and systematically analyzed the influence laws of freeze-thaw action on the physical and mechanical properties such as mass loss,longitudinal wave velocity,and mechanical parameters of rock mass.Based on obtaining the evolution characteristics of the main physical property parameters of the slate,the damage evolution equation considering the influence of the number of freeze-thaw cycles was constructed,and the damage expansion process and failure mode of slate at different freeze-thaw stages were deeply analyzed based on the numerical simulation method.The test results show that with the increase of the number of freeze-thaw cycles,the mass of slate gradually decreases,the propagation speed of longitudinal waves significantly reduces,the uniaxial compressive strength and elastic modulus continuously decay,and the overall trend shows an obvious deterioration.There is a negative exponential attenuation relationship between the elastic modulus and the number of freeze-thaw cycles.After 20 freeze-thaw cycles,the decrease in the elastic modulus exceeds 50%,indicating that the freeze-thaw process has a significant weakening effect on the structural integrity of the rock mass.In terms of microstructure,the initial micro-fractures within the slate gradually expand and connect,the damaged area increases,and the local cracks develop into identifiable macroscopic cracks.With the accumulation of the number of freeze-thaw cycles,the failure mode of rock has changed from the early single through fracture to a complex failure form with multiple non-through fractures coexisting,and the failure paths tend to be dispersed and nonlinear.The numerical simulation results further indicate that freeze-thaw damage not only reduces the overall bearing capacity of the slate,but also promotes the concentrated distribution of the damage area in the middle of the specimen and the joint parts at both ends.The evolution of the damage field is highly consistent with the stress concentration area.This reveals the coupling effect characteristics of freeze-thaw cycles on the strength and structural evolution mechanism of slate.
作者
刘利杰
杨天鸿
张鹏姣
刘亚超
LIU Lijie;YANG Tianhong;ZHANG Pengjiao;LIU Yachao(Institute of Science and Technology,Zhunneng Group Company,Ordos 010300,China;School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China)
出处
《煤矿安全》
北大核心
2025年第9期81-89,共9页
Safety in Coal Mines
基金
鄂尔多斯市科技重大“揭榜挂帅”资助项目(JBGS−2023−003)
国家重点研发计划资助项目(2022YFC2903903)。
关键词
冻融循环
岩体损伤劣化
露天边坡
弹性模量
损伤模型
数值模拟
freeze-thaw cycles
rock mass damage deterioration
open pit stope
elastic modulus
damage model
numerical simulation
作者简介
刘利杰(1973-),男,黑龙江七台河人,教授级高级工程师,硕士,主要从事露天煤矿科研管理方面的工作。E-mail:13705710@ceic.com;通讯作者:杨天鸿(1968-),男,辽宁沈阳人,教授,博士研究生导师,博士,主要从事露天边坡安全监测预警方面的教学和研究工作。E-mail:yangtianhong@mail.neu.edu.cn。
