考虑水化学损伤的岩石真三轴蠕变本构模型

为了准确描述岩石在酸性环境下真三轴蠕变行为的各阶段特征,基于水岩作用的化学动力学理论,定义了考虑PH值与时间的化学损伤因子,将弹性体,非线性Kelvin体,线性Kelvin体和黏弹塑性体进行串联,并考虑岩石在真三轴应力作用下的实际情况,建立岩石酸腐与真三轴应力耦合作用下的损伤蠕变本构模型,通过已有的蠕变试验数据对该模型进行参数辨识与验证,并通过数据拟合得到岩石在真三轴应力下的屈服面方程,探讨中间主应力对蠕变模型的影响.结果表明,推导的本构模型能很好地描述岩石在酸腐作用下真三轴蠕变行为的各阶段特性,验证了其合理性与准确性.

A TRUE TRIAXIAL CREEP CONSTITUTIVE MODEL FOR ROCK CONSIDERING HYDROCHEMICAL DAMAGE

In order to accurately describe the characteristics of each stage of rock creep behavior under the combined action of acid environment and true triaxial stress, based on the chemical kinetic theory of water-rock interaction, a chemical damage factor considering pH and time is defined. The elastic body, nonlinear Kelvin body, linear Kelvin body, and visco-elastic-plastic body are connected in series, and the actual situation under the action of true triaxial stress is considered at the same time, a damage-creep constitutive model considering the coupling of rock acid corrosion and true triaxial stress is established. The parameters of the deduced model are identified and verified with the existing experimental research results. The yield surface equation of rock under true triaxial stress is obtained by data fitting, and the influence of intermediate principal stress on the creep model is discussed. The results show that the derived constitutive model can well reflect creep properties of the rock under acid corrosion The true triaxial creep characteristics under the action have certain rationality and practicability.