摘要
高寒地区矿山边坡岩体会经历冻融循环作用,引起岩体结构损伤和强度弱化,对矿山边坡的稳定性构成危害。水泥砂浆作为模拟裂隙边坡岩体常用的类岩石材料,其配合比对该类岩石材料抗冻性影响较大。为探究冻融作用下水灰比对类岩石材料物理力学特性的影响机制,制作了7种不同水灰比的类岩石——水泥砂浆标准试样,进行了不同次数的冻融循环试验及0~50次冻融后的单轴压缩试验。结果表明:①冻融前,随着水灰比的增大,试样初始孔隙率增大、密度降低,进而导致其波速下降;冻融过程中,波速随着冻融次数的增加而减小,且水灰比越大,波速损失率越高。②随着水灰比增大,类岩石材料的单轴抗压强度、弹性模量均出现了先增大后减小的现象;当水灰比为0.325~0.35时,类岩石试样的单轴抗压强度最高且抗冻性能最好。③随着冻融循环次数增加,应力应变曲线趋于扁平化,试样由脆性逐渐向延性转化,且水灰比越大,试样孔隙压密阶段变形越大。研究成果可为寒区矿山边坡及相关岩体工程类裂隙岩体冻融试验中的配比设计提供借鉴。
The rock mass of the mine slope in the alpine region will experience the freeze-thaw cycle,causing damage and weakening of the rock mass structure,which will pose a hazard to the stability of the mine slope.Cement mortar is a commonly used rock-like material to simulate fractured rock mass,and its mixing ratio has great influence on the frost resistance of this kind of rock material.In order to investigate the influence of water cement ratio on the physical and mechanical properties of rock-like materials under freeze-thaw,rock-like standard specimens with seven different water cement ratios were prepared.Freeze-thaw cycles and uniaxial compression tests after 0~50 cycles were carried out.The results show that:①In the absence of freezing-thawing,increasing water cement ratio,the porosities and densities of the specimens increase while the P-wave velocities decrease.During freezing-thawing,the P-wave velocity decreases with the increase of freezingthawing cycles,and it reduces faster as the water cement ratio increase.②With the increase of water-cement ratio,the uniaxial compressive strength and elastic modulus of rock-like materials increase firstly and then decrease.When water cement ratio is 0.325~0.35,the uniaxial compressive strength of rock-like materials is the highest and the frost resistance is the best.③With the increase of freeze-thaw cycles,the stress-strain curves of these specimens tend to be flat,which illustrates they transform from brittleness to ductility.Besides,a larger deformation of the pore compaction stage arises for higher water cement ratio.The study results can provide a reference in the proportion design of freeze-thaw damage experiment of mine slope and related rock mass engineering.
作者
刘艳章
王瑾
黄诗冰
卢泽鑫
刘雅甜
郭赟林
LIU Yanzhang;WANG Jin;HUANG Shibing;LU Zexin;LIU Yatian;GUO Yunlin(College of Resource and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,Wuhan 430081,China)
出处
《金属矿山》
CAS
北大核心
2020年第11期1-10,共10页
Metal Mine
基金
国家自然科学基金青年基金项目(编号:41702291)
湖北省自然科学基金项目(编号:2015CFA142)
省级大学生创新创业训练计划项目(编号:201810488061)。
关键词
类岩石材料
水灰比
冻融循环
单轴抗压强度
弹性模量
rock-like materials
water cement ratio(w/c)
freeze-thaw cycle
uniaxial compressive strength
modulus of elasticity
