高温和饱水条件下砂岩的抗剪强度与Ⅱ型断裂韧度的相关性

Correlation between the shear strength and the modeⅡfracture toughness of sandstone under high temperature and water saturation

岩石的抗剪强度与断裂韧度会明显受到温度及湿度变化的影响,由于剪切破环和Ⅱ型断裂破环都与剪切相关,因此二者可能具有一定的相关性。基于此,对无处理、100℃加热、200℃加热以及饱水状态下的砂岩试样进行了直剪实验和巴西圆盘断裂实验,测定了在不同处理条件下试件的抗剪强度参数和Ⅱ型断裂韧度,并对二者的相关性进行了讨论。实验结果表明,高温会使试件的抗剪强度和Ⅱ型断裂韧度显著增大,而饱水状态则会使试件的断裂韧度明显下降,试件的抗剪强度和Ⅱ型断裂韧度呈现出良好的线性关系。本文的实验数据对把握砂岩的抗剪强度与Ⅱ型断裂韧度的关系有一定参考价值,实验方法可以为其他类型的岩石的研究提供参考。

The shear strength and the fracture toughness of rock can be obviously affected by the change of temperature and humidity.Since both the shear failure and the mode fracture are related to the shear,there would be a certain correlation between them.Based on this,the direct shear experiments and the Brazilian disc fracture experiments were carried out on sandstone samples under different conditions,such as without treatment,heating at 100℃,heating at 200℃and saturated with water,respectively.The shear strength parameters and the modeⅡfracture toughness of the specimens under different treatment conditions were measured and the correlation between them was discussed.The experimental results show that high temperatures will significantly increase the shear strength and the modeⅡfracture toughness of the specimen,while the saturated state will significantly reduce the fracture toughness of the specimen.The shear strength shows a good linear relationship with the modeⅡfracture toughness of the specimen.The experimental data have certain reference value for grasping the relationship between the shear strength parameters of sandstone under high temperature and saturated water condition and the modeⅡfracture toughness.The test method and process can provide reference for the research of other types of rocks.