摘要
针对现有岩体蠕变力学模型在岩体加速蠕变阶段模拟存在的不足,基于Kachanov-Rabotnov蠕变损伤理论研发一种非线性元件,并将该非线性元件和Burgers蠕变模型串联形成六元件的非线性黏弹塑性蠕变模型,以实现对含软弱结构面岩体加速蠕变阶段的模拟。研究结果表明:根据所建立的模型,若试样未发生加速蠕变,则蠕变变形为稳态蠕变速率与时间的积;若发生加速蠕变,则需要乘以材料常数λ;试样在衰减蠕变阶段的蠕变速率随时间逐渐降低;当剪切应力较低时,剪切蠕变速率减小至恒定值,处于稳态蠕变阶段;随着剪应力增加,经过稳态蠕变后的试样蠕变速率迅速增加,蠕变变形也急剧增加并最终导致试样被破坏;所提出的模型能够描述结构面的时间相关特性,可以对含软弱结构面岩体的剪切蠕变特性进行较全面描述。
In view of the simulation defects of existing research in mechanical creep model of rock mass in the accelerated creep stage, based on the Kachanov-Rabotnov creep damage theory, a nonlinear element was developed, and a nonlinear viscoelastoplastic creep model composed of six elements by connecting the developed element and the Burgers creep model in series was formed to realize the accelerated creep stage simulation of rock mass containing weak structural plane. The results show that, according to the established model, if accelerated creep does not occur, the creep deformation is the multiplication of steady state creep rate and time;if accelerated creep occurs, the material constant λ additionally needs to be multiplied. The creep rate of the specimen decreases with time in the decay creep stage. When the shear stress level is low, the shear creep rate decreases to a constant value and remains in the steady-state creep stage. With the increase of shear stress, the creep rate of the sample after steady creep increases rapidly, and the creep deformation also increases sharply, finally leading to the failure of the sample. The proposed model can describe the time-dependent characteristics of structural plane and the shear creep characteristics of rock masses with weak structural planes comprehensively.
作者
赵晨阳
雷明锋
贾朝军
张逆进
彭龙
龚琛杰
ZHAO Chenyang;LEI Mingfeng;JIA Chaojun;ZHANG Nijin;PENG Long;GONG Chenjie(School of Civil Engineering,Central South University,Changsha 410075,China;Key Laboratory of Engineering Structure of Heavy Haul Railway,Central South University,Changsha 410075,China;The 7th Engineering Co.Ltd.,of China Railway 12th Bureau Group,Changsha 410029,China;No.3 Engineering Co.Ltd.of CCCC Third Harbor Engineering Co.Ltd.,Nanjing 210011,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第10期3541-3549,共9页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51978669,U1934211,52008403)
湖南省青年基金资助项目(2020JJ5732)
中南大学中央高校基本科研业务费专项资金资助项目(2021zzts0229)。
关键词
软弱结构面
蠕变变形
剪切强度
蠕变模型
损伤
weak structural plane
creep deformation
shear strength
creep model
damage
