循环加卸载下闪长玢岩蠕变特性及损伤本构模型  

Creep property and damage constitutive model of dioritic porphyrite under cyclic loading-unloading

作　　者：刘振[1] 杨圣奇[1,2] 柏正林 黄运龙 LIU Zhen;YANG Sheng-qi;BAI Zheng-lin;HUANG Yun-long(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;Huadong Survey and Design Institute(Fujian)Co.,Ltd.,Fujian 350003,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,徐州221116 [2]中国矿业大学力学与土木工程学院,徐州221116 [3]华东勘测设计院(福建)有限公司,福州350003

出　　处：《工程科学学报》2022年第1期143-151,共9页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(41272344)。

摘　　要：分级加载压缩蠕变试验未能充分考虑稳定蠕变中的黏塑性应变,故采用三轴循环加卸载压缩蠕变试验来实现岩石的黏弹、塑性应变分离,从而使岩石黏弹、塑性应变在岩石蠕变的各个阶段得以充分考虑.以某水电站闪长玢岩为例,探讨该类岩石蠕变特性.在破坏前,岩石的瞬时弹性应变以及瞬时塑性应变随着偏应力逐级增大呈线性增长;随着偏应力的增加,黏弹性应变和黏塑性应变呈非线性增长.引入一个分数阶Abel黏壶与Kelvin模型串联形成新型黏弹性模型;用分数阶Abel黏壶代替传统的黏塑性模型中的线性牛顿体并基于损伤建立黏塑性损伤模型.然后将新型黏弹性模型和黏塑性损伤模型与瞬时弹性模型和瞬时塑性模型串联组成一个新的岩石蠕变损伤模型.最后将该模型与岩石蠕变曲线进行拟合,从而证明该模型的适用性.The hierarchical loading compression creep test fails to fully consider the viscoplastic strain in a stable creep.Thus,the triaxial cyclic loading compression creep test is adopted to realize the separation of viscoelastic and viscoplastic strain to fully consider the two strains in each stage of the creep.With the development of hydropower project construction in China being moved towards the mountain valley,the geological conditions and engineering environment faced by geotechnical engineering become more complex.Moreover,in the process of geotechnical engineering design,engineering construction,and safe operation,the effect of the rheological,mechanical properties of rock becomes more difficult to ignore.This engineering problem is becoming more significant for the staff involved.Therefore,rheological,mechanical properties of rock have become a very important research content.This study took the diorite porphyry of one hydropower station as an example to discuss the creep characteristics of this type of rock.Before the failure,the instantaneous elastic strain and instantaneous plastic strain increase linearly as the deviator stress gradually increases.With increased deviator stress,the viscoelastic strain and viscoplastic strain exhibit a nonlinear increase.The fractional Abel viscous pot and Kelvin model were introduced to form a new viscoelastic model.The fractional Abel viscous pot was used to replace the linear Newtonian fluid in the traditional viscoplastic model,and a viscoplastic damage model was established based on the damage variables.The new viscoelastic plastic model and viscoplastic damage model were then connected in series with the transient elastic model and transient plastic model to form a new rock creep damage model.Finally,the model is fitted with the rock creep curve to prove the applicability of the model.

关 键 词：循环加卸载 应变分离 分数阶Abel黏壶 损伤变量 本构模型 

分 类 号：TU45[建筑科学—岩土工程]