煤层顶板砂岩高温状态下力学特征试验研究

对44块鹤壁六矿煤层顶板砂岩试件在高温下和高温后的力学性质进行试验研究,揭示砂岩的强度和变形特征随温度的变化规律。试验结果表明:随温度升高,高温下和高温后的砂岩的弹性参数(峰值强度、弹性模量、变形模量)均逐渐降低,但总体变化趋势相似,个别试件的弹性参数在400℃前高于常温状态;两者相比,高温后砂岩的峰值强度、弹性模量和变形模量有所提高,两者受温度影响均以脆性破坏为主。这为研究煤炭地下气化时热作用下燃空区的围岩稳定及应力场和位移场的变化规律提供试验依据。

EXPERIMENTAL STUDY ON MECHANICAL CHARACTER OF SANDSTONE OF THE UPPER PLANK OF COAL BED UNDER HIGH TEMPERATURE

The mechanical experiment of 44 sandstone specimens in the sixth mine of Hebi under high temperature and after high temperature is introduced;and the regularities on the strength and deformation character with temperature varying are proposed. The results show that peak-value strength,elastic modulus,and deformation modulus of sandstone under high temperature and after high temperature are gradually decreased with general similar variation tendency. The elastic parameters of some specimens are higher than those under common temperature. Compared with both of them,the peak-value strength,elastic modulus,and deformation modulus of sandstone after high temperature increase by a little and they are all brittle fractures. The results provide experimental basis for stability of surrounding rock when heat exits in the place of firing and variation regularity of strain field and displacement field.