红层砂岩高温后效蠕变试验研究

温度是影响岩石变形、稳定的重要因素。通过对红层砂岩开展高温后的蠕变试验，揭示了温度对红层砂岩蠕变特性的影响规律，并基于Burgers模型建立考虑温度效应的蠕变损伤模型，分析了温度对模型参数的影响规律。研究表明:510~550 ℃是红层砂岩力学性质转变的节点温度区间，低于该温度区间时，温度升高，试样的峰值强度增加，延性增强，长期强度减小；高于该温度区间时，温度升高，试样的峰值强度、峰值应变减小，长期强度增加；瞬时应变随温度的升高而线性增大。相同应力条件下，随着经历温度的升高，试样瞬时应变、稳态蠕变速率以及进入稳定蠕变阶段的时间增加，进入加速蠕变阶段的时间减小，加速蠕变曲线变陡。

Creep tests of red-bed sandstone after high temperature

Temperature is an important factor affecting rock deformation and stability. The influence of temperature on the creep characteristics of red-bed sandstone is revealed through the creep test of red-bed sandstone after different high temperatures, and a creep damage model considering the temperature effect based on the Burgers model is established to analyze the influence rule of temperature on model parameters. The research results indicate that 510~550 °C is the nodal temperature range for the change in mechanical properties of red-bed sandstone. Below this temperature range, with the temperature increases, the peak strength of specimen increase, ductility increases, and the long-term strength decreases. Above this temperature range, with the temperature increases, the peak strength and peak strain of specimen decrease, and the long-term strength increases. The instantaneous strain increases linearly with the increasing temperature. Under the same stress conditions, with the temperature increases, the instantaneous strain of specimen, the steady-state creep rate and the time to enter the stable creep stage increase, the time to enter the accelerated creep stage decreases, and the acceleration creep curve becomes steeper.