岩盐弹塑性损伤耦合模型研究

Coupled elastoplastic-damage model for salt rock

岩盐力学模型是进行能源岩盐储存工程稳定性分析的基础,而损伤和塑性机制并存且相互耦合是岩盐力学行为的基本特点。采用云应岩盐,进行了多组围压条件下的三轴压缩试验,分析了不同围压下岩盐的变形特征。在试验分析的基础上,提出了一种能够描述岩盐特性的弹塑性损伤耦合的模型,该模型描述了岩盐损伤的演化和塑性变形的耦合关系,并引入了一种非关联的塑性流动法则来描述岩盐从塑性体积压缩到膨胀的转化。采用该模型对在三轴压缩下的岩盐应力-应变关系进行了模拟分析,并与试验数据进行了对比,结果表明该模型能够较好地描述岩盐的主要力学和变形特性。

Mechanical model is the basis for analysis of energy deposit engineering stability in salt seam;and the coupled damage and plasticity mechanism is the basic mechanical behavior of rock salt.Using rock salt from Yun-Ying,triaxial compression tests are performed under different confining pressures;and the deformation characteristics of salt rock are analyzed.Based on a brief account of experimental investigation,a coupled elastoplastic-damage model for salt rock is proposed.The model can describe the coupled relations between plastic deformation and damage evolution;and also a non-associated rule is preferred in order to describe a transition of plastic volumetric strain from compressibility to dilatancy.A simulation case is conducted to investigate the deformation processes of salt rock under triaxial compression;and the results show that the numerical simulations perfectly agree with the experimental data;so it is shown that the proposed coupled elastoplastic damage model is able to describe the main mechanical and deformation properties of salt rock.