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对砂岩经历饱水及不同温度(25~1 000℃)前后的物理参数、纵波波速及力学性能参数进行了量测,分析了砂岩试样的密度变化率,纵波波速的变化规律,抗压强度、抗拉强度的变化及压缩破坏形态的差异。结果表明砂岩在经历饱水、高温后内部微裂隙发展,使结构致密性下降,超声波速降低;经历不同温度后砂岩波速的变化率与温度等级近似呈线性关系;800~1 000℃之间存在一个温度阀值,高于此温度后砂岩的密度、纵波波速、强度都急剧降低;温度的不同也会影响砂岩的破坏形态,200~800℃范围内及饱水后砂岩的破坏模式基本为剪破坏,25~100℃范围内破坏模式为张破裂。基于试验结果结合砂岩材料的微观结构特征对温度和饱水作用下砂岩各方面性质的变化进行了机理分析,结果可为实际岩体工程提供一定参考。
The physical parameters, longitudinal wave velocity and mechanical property parameters of sandstone before and after undergoing saturated water and different temperatures (25-1000 ℃) were measured. The change rate of density, longitudinal wave velocity and compressive strength , Tensile strength changes and compression damage morphology differences. The results show that the sandstone undergoes the development of internal micro-cracks after being saturated with water and high temperature, resulting in the decrease of structural densities and the decrease of the ultrasonic velocity. The change rate of the sandstone velocities is approximately linear with the temperature gradation after different temperatures. Between 800 and 1000 ℃, A temperature threshold above which the sandstone density, longitudinal wave velocity, and intensity sharply decrease; the difference in temperature also affects the destructive morphology of the sandstone. The failure modes of the sandstone at 200-800 ° C and after saturation are basically shear Destruction, 25 ~ 100 ℃ within the failure mode for Zhang fracture. Based on the experimental results and the microstructure characteristics of sandstone materials, the mechanism of the changes of sandstone properties in all aspects under the influence of temperature and water saturation is analyzed. The results can provide some reference for the actual rock mass engineering.