含孔隙冻融岩石的损伤本构模型

(1.西安科技大学 建筑与土木工程学院,陕西 西安 710054; 2.西安科技大学 理学院,陕西 西安 710054; 3.陕西省西安公路管理局,陕西 西安 710002)

孔隙率; 本构模型; 模型参数; 损伤

Damage constitutive model of porous rock under freeze-thaw
MENG Xiang-zhen1,ZHANG Hui-mei2,KANG Xiao-ge3

(1.College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.College of Sciences,Xi'an University of Science and Technology,Xi'an 710054,China; 3.Xi'an Highway Administration of Shaanxi Province,Xi'an 710002,China)

porosity; constitutive model; model parameter; damage

DOI: 10.13800/j.cnki.xakjdxxb.2019.0417

备注

针对现有损伤本构模型所存在的局限与不足,在深入研究孔隙岩石变形破坏特征的前提下,将岩石视为孔隙、损伤与未损伤3部分。以孔隙率反映岩石体积变化,基于weibull随机分布,依据损伤力学原理,确立含孔隙冻融岩石的损伤本构模型,并以理论表达的形式确定模型参数,最后利用冻融岩石的力学特性试验结果验证其合理性。结果 表明:推导的本构模型与试验结果吻合较好,且岩石初始阶段时孔隙压密以及应变软化特性都能更好地反映出来; 通过峰值条件获得的模型参数表达式,可反映冻融岩石的损伤演化与变形破坏的一般规律,增强了模型的适用性。

With the limitations and deficiencies of the existing damage constitutive model in view, the rock was abstracted as three parts of pore, damage and non-damage based on weibull random distribution, after having investigated the deformation and failure characteristics of porous rock. Due to the fact that porosity reflects the change of rock volume, the damage constitutive model of porous rock under freeze-thaw was established based on the damage mechanics theory, and the model parameters were determined in the form of expressions. Finally, the rationality of the model was verified by using the conventional triaxial freeze-thaw text to obtain mechanical parameters. The results of the study show that: The establishment of constitutive model is reasonable, and the pore pressure and softening properties of the rock can be better reflected in the initial period. The expression of the model parameters obtained through the peak conditions can reflect the law of the damage and the deformation of rock under freeze-thaw, which enhance the applicability of the model.