高温后节理砂岩强度及变形破坏特性

利用单轴压缩试验对经历不同温度后节理砂岩的物理力学性质进行分析研究,得出了关于节理砂岩高温后应力-应变曲线、峰值强度、峰值应变及弹性模量等参数随温度的变化规律。同时利用声发射仪器监测岩石压缩过程中的声发射分布特征,探讨不同温度对于变形破坏机理的影响。分析结果表明:温度对于节理砂岩性质的影响是多方面的。当经历温度较低时,温度对于节理砂岩性质的增强效果大于削弱效果;而当温度较高时,则反之。400℃为试验的温度阈值。在400℃前后,节理砂岩的峰值强度、峰值应变、弹性模量等均呈现不同的变化趋势。节理砂岩经历高温后,产生的裂纹主要分布在节理附近,且经单轴压缩破坏后,裂隙同样主要沿节理分布,受热后,岩石的破坏模式由脆性破坏向延性破坏转变。

Strength and deformation properties of post-high-temperature joint sandstone

Based on the uniaxial compression test，the physical and mechanical properties of joint sandstone under different high temperatures were studied．The scope included the variation of a series of stress-strain curve，peak stress，peak strain and elastic modulus with temperature changing．Meanwhile，using the acoustic emission instrument，the distributional feature of acoustic emission was monitored in the process of rock compression in order to discuss the effect on the mechanism of deformation and failure of joint sandstones under different temperatures.The influence of temperature on joint sandstone properties is various.When temperature is low，the enhancement effect of joint sandstone properties is greater than the weakening effect；And when the temperature is higher，the result is on the contrary.400 ℃ is the temperature threshold value in the test.Before and after it，the peak stress，peak strain and elastic modulus show a different trend.The crack is mainly distributed in the joint nearby after high temperature，and the crack also mainly along the joint after uniaxial compression.The failure mode of the sandstone has transferred from brittle failure to ductile failure when heated.