【摘要】：熱開裂已成為地下高溫巖土工程安全運行的主要威脅之一。以煤炭地下氣化等地下工程中的砂巖為對象,通過試驗對砂巖熱膨脹系數(shù)在升溫過程和保溫過程中的變化規(guī)律進(jìn)行了系統(tǒng)的研究。研究表明,升溫過程中熱膨脹系數(shù)隨升溫時間的變化規(guī)律呈反曲線函數(shù)關(guān)系,分為4個階段:初期階段呈下凹形;第2階段基本呈斜直線上升,熱膨脹系數(shù)增長率基本恒定;第3階段呈現(xiàn)上凸形;最后,熱膨脹系數(shù)增長率下降并逐漸平穩(wěn)。保溫試驗過程中隨著溫度升高,試樣熱膨脹系數(shù)逐漸增加;但溫度達(dá)到700℃后,試樣熱膨脹系數(shù)增加趨勢明顯減緩,趨于平穩(wěn),試樣軸向高度變化速度降低。
[Abstract]:Thermal cracking has become one of the main threats to the safe operation of underground high temperature geotechnical engineering. Taking the sandstone in underground engineering such as underground coal gasification as an example, the variation of thermal expansion coefficient of sandstone in the process of heating and heat preservation is studied systematically through experiments. The results show that the variation of thermal expansion coefficient with heating time is a function of inverse curve, which can be divided into four stages: the initial stage is concave, the second stage is inclined straight line, the growth rate of thermal expansion coefficient is basically constant. Finally, the growth rate of thermal expansion coefficient decreased and gradually stabilized. The thermal expansion coefficient of the sample increases gradually with the increase of temperature, but when the temperature reaches 700 鈩，

本文編號：2352526