冻融循环影响下金属矿山边坡坚硬岩石物理力学性质研究

study of physico-mechanical characteristics of slope hard rocks of metal mine influenced by freeze-thaw cycles

利用西藏玉龙铜矿边坡花岗斑岩、灰岩、石英砂岩3种典型的坚硬岩石样本进行冻融循环实验,根据矿区所在地多年气象资料、采场所处自然环境,进行冻融温度区间为-20~20℃的岩石冻融循环试验,模拟了岩石冻融过程,研究了饱水状态坚硬岩石在冻融循环作用下的质量、体积、单轴抗压强度、抗拉强度、冻融系数、风化程度的变化规律,并绘出了冻融次数与试样的抗压强度、抗拉强度、冻融系数的拟合关系曲线,为坚硬岩石冻融研究提供了试验依据。将实验结果应用于西藏玉龙铜矿花岗斑岩边坡的具体实例中,采用强度折减法计算出了矿山边坡冻融风化前、后的安全系数,为寒区露采矿山边坡的稳定性研究提供了参考。

The experiment of cycle of freezing and thawing has been conducted using the rock specimens from Tibet Yulong copper mine slope containing granite porphyry,quartzose sandstone and limestone. Experimental temperature has been controlled between-20 ℃ and 20 ℃ according to meteorological data and natural environment of the mine, volume, quality, uniaxial compressive strength, tensile strength, coefficient of freezing and thawing, and the change rule of decay rate of hard rocks have been measured and studied under the condition of water saturated state. The relation curve of freezing-thawing cycles and uniaxial compressive strength, tensile strength, coefficient of freezing and thawing have been fitted using Matlab software. The experimental results have been applied in the slope of the Tibet Yulong copper mine. Safety factors of the slope before and after freezing-thawing test have been calculated and compared by using strength reduction technique. This study can be used for similar mines.