考虑黏弹塑性应变分离的岩石复合蠕变模型研究  

Study on composite creep model of rock considering viscoelastic plastic strain separation

作　　者：张亮亮 王晓健[1,2] ZHANG Liangliang;WANG Xiaojian(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]安徽理工大学省部共建深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001

出　　处：《中南大学学报（自然科学版）》2021年第5期1655-1665,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51874005)。

摘　　要：依据不同偏应力下石灰岩循环加卸载蠕变试验数据提出和建立瞬时弹性体(IEB)、瞬时塑性体(IPB)、非线性黏弹性体(NVEB)和黏塑性体(VPB)分别用于描述瞬时弹性应变、瞬时塑性应变、非线性黏弹性应变和黏塑性应变,并将这四者串联,建立能够同时反映岩石加、卸载过程的复合蠕变模型。根据非线性流变理论推导岩石在一维、三维应力状态下的复合蠕变模型加卸载蠕变本构方程,最后采用试验数据对模型合理性进行验证。研究结果表明:当复合蠕变模型综合考虑瞬时弹性应变、瞬时塑性应变、非线性黏弹性应变和黏塑性应变时,模型理论曲线与试验曲线高度吻合;所建模型不仅能够描述石灰岩加载过程中非线性蠕变特征,还能描述卸载过程中应变随时间的变化规律,不同偏应力下试验曲线与理论曲线相关系数均大于0.968,对比结果验证复合蠕变模型的合理性和可行性。Based on the cyclic loading and unloading creep test data at different deviator stress levels of limestone,the instantaneous elastic body(IEB),the instantaneous plastic body(IPB),the nonlinear viscoelastic body(NVEB)and the viscoplastic body(VPB)were proposed and established to describe the instantaneous elastic strain,the instantaneous plastic strain,the nonlinear viscoelastic strain and the viscoplastic strain respectively.And they were connected in series to establish a composite creep model which could simultaneously reflect the loading and unloading creep process of rock.According to the nonlinear rheological theory,the loading and unloading constitutive equations of the composite creep model of rock in one-dimensional and three-dimensional stress state were deduced.Finally,the rationality of the model was verified by the test data.The results show that the theoretical curve of the model is highly consistent with the test curve,when the composite creep model considers the instantaneous elastic strain,the instantaneous plastic strain,the nonlinear viscoelastic strain and the viscoplastic strain.The model can not only describe the nonlinear creep characteristics in the loading process of limestone,but also describe the change rule of strain with time in the unloading process,and the correlation coefficients between the test curve and the theoretical curve are greater than 0.968 under different deviator stresses.The comparison results verify the rationality and feasibility of the composite creep model.

关 键 词：岩石力学 蠕变 分级加卸载 黏弹塑性 非线性 

分 类 号：TU45[建筑科学—岩土工程]