摘要
利用MTS815 Flex Test GT岩石力学试验系统,对盐岩和大理岩进行了单轴压缩下的7级加卸载试验和低周循环加卸载试验测试,对盐岩和大理岩的卸载模量进行了探讨。低周循环试验加载波形采用正弦波,频率1Hz,循环应力幅值小于其平均抗压强度,单级应力幅值为30个振动循环。通过试验,得到了盐岩应力应变滞回环均为条带状,大理岩则均为尖叶状;盐岩在加卸载部位具有较大不可逆变形,对应弹性响应较慢,大理岩则反之;盐岩卸载模量变化趋势受加载测试方法影响较大,而大理岩在2种试验条件下得到的卸载模量变化趋势相似;加载应力幅值比加卸载循环数对盐岩不可逆变形增量影响更加显著。损伤变量研究结果表明,利用低周循环加卸载方法测试具有显著时间效应变形岩石的损伤弹性模量,能更真实反映其损伤特征。
The uniaxial seven stress levels cyclic loading and unloading test for salt rock and marble were carried out on MTS815 Flex Test GT rock mechanics test system,and the damage unloading modulus were discussed.The loading test wave for low cyclic loading test was sine wave,and its frequency was 1.0 Hz.The maximum of cyclic stress was less than the value of the average intensity of compression,and the cyclic number of every level cyclic stress was 30 cycles.The test showed that the hysteresis loop of the curve of strain and stress was the ribbon for salt rock and tine lobation for marble stone.The salt rock had larger irreversible deformation at reloading and unloading position where corresponding elastic deformation response was slow,but the results for the marble stone were contrary.Because the unloading modulus for salt rock was influenced by test method,the changing tendency of unloading modulus for salt rock during the two test methods was reverse,while the results for marble stone were consistent during the two test methods.The effect on the increment of irreversible deformation for salt rock was more prominent for the condition of the loading stress amplitude than that of the cyclic numbers.The damage variable test results revealed that it was more authentic to describe the damage property through the damage elastic modulus which was tested by the low cyclic loading test method for rock with marked visco-plastic deformation.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2011年第4期57-62,共6页
Journal of Sichuan University (Engineering Science Edition)
基金
国家"973"计划资助项目(2011CB201201
2010CB226802)
国际科技合作资助项目(2007DFB60100)
中央高校基本科研业务费专项资金资助项目(2009SCU11073)
关键词
损伤变量
卸载模量
粘性变形
盐岩
damage variable
unloading modulus
visco-plastic deformation
salt rock
