加载速率效应下恒温花岗岩损伤破坏规律研究  

Study on Damage and Failure Law of Thermostatic Granite under Loading Rate Effect

作　　者：鲍先凯 姜斌 于超云 时睦涵 张武 Bao Xiankai;Jiang Bin;Yu Chaoyun;Shi Muhan;Zhang Wu(School of Civil Engineering,Inner Mongolia University of Science and Technology,Baotou Neimenggu 014010,P.R.China;Inner Mongolia Autonomous Region Building Structure Disaster Prevention and Mitigation Engineering Technology Research Center,Baotou Neimenggu 014010,P.R.China;Inner Mongolia Autonomous Region Key Laboratory of Civil Engineering Safety and Durability,Baotou Neimenggu 014010,P.R.China)

机构地区：[1]内蒙古科技大学土木工程学院,内蒙古包头014010 [2]内蒙古自治区建筑结构防灾减灾工程技术研究中心,内蒙古包头014010 [3]内蒙古自治区土木工程安全与耐久重点实验室,内蒙古包头014010

出　　处：《地下空间与工程学报》2024年第3期788-799,847,共13页Chinese Journal of Underground Space and Engineering

基　　金：内蒙古自然科学基金(2020LH05018,2020BS05017);内蒙古科技大学建研所开放基金(JYSJJ-2021M19,JYSJJ-2021Q06)。

摘　　要：为研究恒温花岗岩的加载速率效应,以60℃恒温花岗岩试样为实验对象,开展不同加载速率下花岗岩单轴压缩试验并采用声发射技术实时监测并进行数值模拟计算,分析试样的力学特性和破坏演化规律。结果表明:随加载速率增加,花岗岩弹性模量先减小后增大,泊松比先增大后减小;0.005 mm/s加载速率下试件声发射信号曲线平滑、增长缓慢,0.01 mm/s、0.015 mm/s加载速率下声发射信号曲线曲率急剧增加,而0.02 mm/s加载速率下声发射信号断崖式上升;不同加载速率下的张拉裂纹散点分布靠近AF轴,剪切裂纹散点分布均远离AF轴,张拉裂纹散点远多于剪切裂纹;声发射RA-AF演化特征分析和数值模拟分析都很好地印证了花岗岩低加载速率下的破坏形式是以张拉为主的张拉-剪切混合破坏,高加载速率下的破坏形式主要为张拉破坏,这与试验结果高度吻合。To study the loading rate effect of the constant thermostatic granite,the 60℃constant thermostatic granite sample was taken as the experimental object,and the granite uniaxial compression test under different loading rates was carried out.The acoustic emission technology was used for real-time monitoring and numerical simulation calculation,and the mechanical properties and failure evolution law of the sample were analyzed.The results show that:with the increase of loading rate,the elastic modulus of granite decreases first and then increases,and poissons ratio increases first and then decreases.At the loading rate of 0.005 mm/s,the AE signal curve of the specimen is smooth and grows slowly;at the loading rate of 0.01 mm/s and 0.015 mm/s,the AE signal curve curvature increases sharply,while at the loading rate of 0.02 mm/s,the AE signal rises steeply.Under different loading rates,the distribution of tensile cracks is close to the AF axis,while the distribution of shear cracks is far away from the AF axis,and the distribution of tensile cracks is far more than that of shear cracks.The AE RA-AF evolution characteristic analysis and numerical simulation analysis have well confirmed that the failure mode of granite under low loading rate is mainly tension-shear mixed failure,while the failure mode under high loading rate is mainly tension-shear failure,which is highly consistent with the experimental results.

关 键 词：花岗岩 加载速率 声发射振铃 RA-AF演化特征 损伤破坏 

分 类 号：TU45[建筑科学—岩土工程]