中文摘要：

利用RMT–150B岩石力学试验系统,对细晶大理岩试样在应变速率2×10-5～5×10-3s-1范围内进行了6级应变速率下的单轴压缩试验,分析应变速率对大理岩应力速率、峰值强度、弹性模量、弱化模量、峰值应变、泊松比、积聚能、释放能以及破裂形式等力学性质的影响。研究结果表明,不同应变速率下单轴压缩过程均经历压密、弹性、屈服和破坏4个阶段。应力速率与应变速率的对数可以用指数形式描述;大理岩的峰值强度与应变速率呈正相关,可采用二次多项式进行描述;大理岩的弹性模量、弱化模量和峰值应变受应变速率影响不大,泊松比与应变速率呈指数关系;试验过程中试样峰值前积聚能量、峰值后释放能量与应变率呈正相关,表明应变率越高微裂纹扩展越严重。在应变速率低于5×10-4s-1时,试样以剪切破坏为主,随着应变速率的增加,试样破坏模式从局部剪切失稳破坏向全面剪胀失稳破坏转变,在高应变速率下更容易形成锥形破坏。研究结果能够对岩爆防治和工程抗震设计提供一定参考。

英文摘要：

The uniaxial compression tests on marbles were performed under six levels of strain rates ranging from 2×10-5 to 5×10-3 s-1 by using RMT–150B servo machine.The effects of strain rate on stress rate,peak strength,elasticity modulus,Poisson？s ratio,softening modulus,strain at peak stress,storage energy,releasing energy,and fracture behavior were analyzed.The results show that the uniaxial compression process including four stages：compression,elasticity,yielding and failure stages under different strain rates.The relationship of stress rate and logarithm of strain rate could be expressed in exponential form.The peak strength of marble had a positive correlation with strain rate which could be expressed in quadratic polynomial form.The strain rate has little influence on elasticity modulus,softening modulus,and peak strain.The Poisson？s ratio has a negative correlation with strain rate,which could be expressed in exponential form.The accumulated energy prior to stress peak and released energy after stress peak has a positive correlation with strain rate;and the higher the strain rate is,the more serious cracking is.When strain rate is less than 5 × 10-4 s-1,the samples mainly present shear failure mode.The failure mode would be changed from local shear failure to overall shear failure with the increase of strain rate;and it is easier to form a cone-shape failure under high strain rate.The investigation results can provide a certain references for rockburst prevention and engineering seismic design.