摘要
Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.
运用带有加热装置的电液伺服材料试验机对热处理后和高温下的花岗岩进行了静态力学实验。分析了两种状态下花岗岩的应力-应变曲线及峰值强度、峰值应变和弹性模量随温度的变化规律,并且探讨了两种状态下岩石的破坏形态。结果显示,与热处理后的花岗岩相比,高温下花岗岩脆-延转变的临界温度更低,压密阶段更长,弹性模量更小且损伤更大。此外,与热处理后的花岗岩相比较,高温下花岗岩的峰值应力更小,然而峰值应变却更大,且两者都随着温度的升高变化更加显著。另外,高温处理后和高温下花岗岩的破坏形态明显不同。低于100°C时,两种状态下花岗岩的破坏形态相同,皆表现为劈裂破坏。然而,高于100°C后,热处理后和高温下花岗岩的破坏形态分别表现为劈裂破坏和剪切破坏。
基金
Projects(51304241,11472311,51322403)supported by the National Natural Science Foundation of China
Project(2015CX005)supported by Innovation Driven Plan of Central South University,China
Project(2016zzts456)supported by Independent Exploration and Innovation Foundation of Central South University,China
Project(2015CB060200)supported by the National Basic Research Program of China
