平顶山天安二矿石灰岩膨胀应力的试验研究

Experimental research on the swelling stress of limestone in the second coal mine of Tian'an,Pingdingshan city

为了保证高温过程中岩石工程的稳定性和安全性,采用高温加热炉和扫描电子显微镜研究了高温双向约束条件下石灰岩膨胀应力的变化规律.试验结果表明,加热过程中石灰岩的膨胀应力随加热时间的增加而增加,各温度段之间呈现明显的线性关系,曲线斜率依次增大,不同温度水平曲线的转折点不同.随着温度的升高,石灰岩的膨胀应力不断增加,500℃后增加速度加快.恒温后,膨胀应力和加温时间关系曲线的斜率逐渐减小,但曲线仍平缓上升.高温过程中石灰岩膨胀应力的变化与其微观结构变化密切相关.

In order to ensure the stability and safety of rock engineering under high temperature, the regulation of the swelling stress of limestone under bidirection restraints and high temperature was investigated by heating furnace and scanning electron microscopy. The results show that the swelling stress increases with the heating time increases. Each section on the curves of the swelling stress and heating time is apparently linear, the glopes of the curves increase in turn. The turning points of the curves are different because the experiment temperature levels are different. The swelling stress of limestone increases gradually with the temperature increasing, which increases more quickly after 500℃. After keeping the costant temperature, the glopes of the curves gradually reduce, while the trend still asends. The change of the swelling stress of limestone has closely ralation with the micro - structure of the limetone during high temperature.