考虑温度影响的软岩弹塑性本构模型

煤矿的深度开挖、核废料的地下储存和能量桩的广泛应用等诸多的岩土工程问题都需要考虑温度对软岩力学特性的影响。为了能较为全面地描述软岩的力学特性，基于上下负荷加载面，引入温度等价应力的概念，在tij应力空间下构建了一个可同时考虑温度效应、中间主应力影响、结构性、超固结性等软岩力学特性的弹塑性本构模型。新模型的所有参数都具有明确的物理含义。通过理论曲线与试验结果进行对比，验证了所提本构模型的正确性。最后通过改变模型参数，对新本构模型的性能进行了分析讨论。计算结果表明：（1）增大超固结比发展控制参数m或者减小结构状态发展控制参数m*，将会提升软岩的剪切强度。（2）随着温度的上升，软岩的剪切强度反而减弱。（3）初始的超固结比越大，软岩的剪胀特性更明显；而初始的结构性较大时，其体积应变在剪切的最后阶段表现为剪缩。

Elastoplastic constitutive model for soft rock considering temperature effect

Many geotechnical problems, such as deep excavation of mine, underground storage of nuclear waste and pervasive application of energy piles, need to consider the effect of temperature on the mechanical properties of soft rock. In order to describe the mechanical properties of soft rock more comprehensively, based on the superloading and subloading concept and the concept of temperature-equivalent stress, a new elastoplastic constitutive model for soft rock, which is able to consider the effect of temperature, intermediate principal stress, structure and overconsolidation at the same time, is proposed in the tij stress space. All parameters of the new model have clear physical meaning. By comparing theoretical curves with the experimental results, the correctness of the proposed constitutive model is verified. Finally, by changing the model parameters, the performance of the new constitutive model is analyzed and discussed. Increasing the value of m which controls development of overconsolidation ratio or reducing the value of m* that controls structural state development will enhance the shear strength of soft rock. With the increase of temperature, the shear strength of soft rock declines. The higher the initial overconsolidation ratio is, the more apparent the dilatancy of soft rock becomes. But when initial structure is large, the volume strain of soft rock presents shear contraction in the final shear stage.