温度与加载速率对岩石力学性质的影响  

Effect of temperature and loading rate on mechanical properties of rock

作　　者：陈琳[1] 徐小丽[2,3] 徐银花[1] 

机构地区：[1]南通大学理学院,江苏南通226019 [2]南通大学建筑工程学院,江苏南通226019 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008

出　　处：《广西大学学报（自然科学版）》2016年第1期170-177,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(11202108);中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金(SKLGDUEK1204);南通大学前期预研科研项目(11ZY006)

摘　　要：通过实时高温不同加载速率下花岗岩的单轴压缩声发射试验和扫描电镜试验,研究了岩样在温度和加载速率共同作用下的力学性质与分形特征。研究结果表明:(1)岩样应力—应变曲线可以分成压密、线弹性、非弹性和破坏四个阶段。随着加载速率由0.001 mm/s增加至0.1 mm/s,岩样压密阶段变短,弹性模量增加,峰值应变逐渐减小。(2)岩样峰值应力、振铃计数率与温度的变化规律相一致,均呈现先下降后上升趋势,在600℃时达到最小值。(3)峰值应力、振铃计数率随加载速率的增加呈线性增大趋势。加载速率由0.001 mm/s增加至0.1 mm/s,峰值应力由37.166 MPa增加至53.769 MPa,增幅为44.673%;振铃计数率由107 380增加至141 644,增幅为31.909%。(4)岩样破裂的分形维数与加载速率呈线性增大,但温度超过600℃,岩样结构晶体改变,温度的影响占据了主要因素,导致分形维数随加载速率变化规律不明显。研究成果为岩土地下扰动、工程爆破等实际工程中岩石力学参数的选取提供了有益的参考价值。The acoustic emission experiment on granite under uniaxial compression and different loading rates at real-time high temperatures and the Scanning Electron Microscope experiment were conducted to study the mechanical properties of rock. The results show that stress-strain curves of rock can be divided into four stages： compaction stage,linear elastic stage,non-elastic stage and destruction stage. The compaction stage of rock becomes shorter,the modulus of elasticity increases and the peak strain decreases when the loading rate increases gradually from 0. 001 mm / s to 0. 1 mm / s.The relation between peak stress and temperature is consistent with the relation between ringing counting rate and temperature. The peak stress and ringing counting rate first decrease and then increase with the increase of temperature,and the minimum values are reached at 600 ℃. At different temperatures,the peak stress and the ringing counting rate increase linearly with the increase of loading rate. While the loading rate increases from 0. 001 mm / s to 0. 1 mm / s,the peak stress increases from 37. 166 MPa to 53. 769 MPa,which is increased by 44. 673%; and the ring count rate increases from 107 380 to 141 644,which is increased by 31. 909%. The fractal dimension of rock rupture increases linearly with the loading rate. After 600 ℃,the temperature leads to the change of rock crystal structure,the influence of temperature plays the main role,and the change of fractal dimension with the loading rate is not obvious. The studies provide a useful reference for the selection of the mechanical parameters of rock in underground disturbances and blasting.

关 键 词：温度 加载速率 峰值应力 振铃计数率 分形维数 

分 类 号：TU45[建筑科学—岩土工程]