3种岩石高温后力学性质的试验研究

TESTING STUDY ON MECHANICAL PROPERTIES OF TUFF,GRANITE AND BRECCIA AFTER HIGH TEMPERATURES

通过单轴压缩试验,对不同高温后熔结凝灰岩、花岗岩及流纹状凝灰角砾岩的力学性质进行了研究,分析比较3种岩石峰值应力、峰值应变及弹性模量随温度的变化规律,并研究了峰值应力与纵波波速、峰值应变与纵波波速的关系。试验升温等级设为20℃,200℃,400℃,600℃,800℃五级,升温速度为30℃/min。试验结果表明,高温后3种岩石的峰值应力、弹性模量均有不同幅度的降低,且经历的温度越高,降低的幅度越大。对于峰值应变,熔结凝灰岩、花岗岩的峰值应变随温度的升高而大幅度的增加;但对于流纹状凝灰角砾岩,峰值应变随着温度的升高在降低。此外,峰值应力与纵波波速、峰值应变与纵波波速的关系依赖于不同的岩石而表现出不同的规律。

Based on the uniaxial compression test, the mechanical properties of tuff, granite and breccia after different high temperatures are studied. The scope of this research includes（l） the variation of peak stress, peak strain and elastic modulus with temperature, and （2） the relationship between longitudinal wave velocity and peak stress and peak strain. The temperature varies in the range of 20 ℃, 200℃, 400℃, 600℃, 800℃, and the heating velocity is 30 ℃/min. The results show that the peak stress and elastic modulus decrease with temperature. The higher the temperature is, the larger the decrement of the peak stress and elastic modulus are. For tuff and granite, the peak strain increases with temperature. However, for breccia, it seems that the peak strain decreases with temperature. Furthermore, the relationship among present different laws according to the types of rocks. longitudinal wave velocity, peak stress and peak strain present different laws according to the types of rocks.