水化学及冻融循环对砂岩物理力学特性试验研究

以寒区砂岩为研究对象,考虑水化学溶液的侵蚀和冻融循环的影响,开展不同酸性条件下岩石冻融循环试验,引入岩石损伤变量,定量分析砂岩力学损伤规律。结果表明:随着酸性增强及冻融循环次数的增大,砂岩的弹性模量、抗压强度逐渐减小,砂岩内部损伤逐渐增大;酸性条件与冻融循环的耦合作用加剧岩石的损伤,酸性最强条件下(p H=2),经历60次冻融循环试件弹性模量、抗压强度下降55.70%和54.57%;分析砂岩的弹性模量、抗压强度及损伤变量与冻融循环次数关系,定量关系可表征为指数变化关系。建立岩石力学参数损伤变量,对水化学冻融循环耦合机理进行研究,探究岩石力学性质的劣化机制。研究成果将为不同水化学条件下寒区工程长期稳定性分析提供试验依据。

Experimental Study on Physical and Mechanical Properties of Sandstone by Water Chemistry and Freeze-thaw Cycling

Taking the red sandstone in cold region as the research object, considering the effect of erosion and freezing-thawing cycles, the freeze-thaw cycle test of rock under different acidity conditions is carried out, and the rock damage variable is introduced. The results show that with the increase of acidity and the number of freeze-thaw cycles, the elastic modulus and compressive strength of red sandstone decrease gradually, and the internal damage gradually increases. The elastic modulus, compressive strength and compressive strength of the red sandstone were decreased by 55.70% and 54.57%, respectively. The elastic modulus, compressive strength and damage variable of the red sandstone were Freezing-thawing cycle number relationship, quantitative relationship can be characterized as the exponential relationship. The damage mechanism of rock mechanics parameters was studied, and the mechanism of rock mechanics degradation was studied. The research results will provide experimental basis for the long - term stability analysis of cold region engineering under different water chemistry conditions.