不同温度作用下砂岩巴西劈裂试验研究

Study on the Brazil Split Test of Sandstone under Different Temperatures

为了确保隧道穿越瓦斯、地热等复杂地质条件时的施工安全,借助MTS815岩石力学试验机、SEM、I-PRT(岩石)波速仪对隧道顶板砂岩进行不同温度试验研究,结果表明:随着温度增加,砂岩物理力学特性的损伤程度越来越严重,尤其当温度大于400℃时,砂岩的颜色、质量、体积、声发射事件数以及强度均发生显著变化,并且岩石的破裂方式由脆性逐渐向延性转化。通过对不同温度影响下砂岩波速的变化率进行归一化处理,得到该砂岩样的损伤变量关系式,从而有利于采取相应措施减少岩体的损伤,确保了地下隧道的安全运行。

In order to ensure the construction safety when underground tunnel goes through complicated geological conditions such as gas and subterranean heat, MTS815 test machine for rock mechanics, SEM and I-PRT （rock） instrument for wave velocity were used to conduct tests with different temperatures on the sandstone on the roof of tunnel. The results showed that the damage degree of physical-mechanical properties of sandstone increased dramatically with the increase of temperature. Espe-cially when the temperature was above 400℃ , various indexes of sandstone changed significantly including color, quality, vol-ume, the number of acoustic emission and intensity, and the failure form of rock transfered from brittle to ductile gradually. The change rate of sandstone velocity was normalized under different temperatures, which could obtain the damage variable for mula of sandstone sample so as to be conducive to take measures to reduce the rock damage and to ensure the safe operation of underground tunnel.