中南大学学报（自然科学版）2024，Vol.55Issue(9)：3520-3529,10.DOI:10.11817/j.issn.1672-7207.2024.09.024
滇中红层泥岩剪切蠕变特性及其本构模型
Shear creep characteristics and constitutive model of red-bed mud-stone in Central Yunnan
摘要
Abstract
To ensure the construction safety and long-term operation of the tunnel project in the area where the red-layered mudstone was located,the red layer mudstone in the Shizishan tunnel section of the"Central Yunnan Water Diversion Project"was taken as the research object.Firstly,the creep characteristics of the tunnel were studied by using the shear creep test method under graded loading.Secondly,trigger-type non-steady-state acceleration elements,nonlinear elastic elements and composite viscous elements were developed by utilizing nonlinear viscoelastic theory.Thirdly,these models were effectively integrated to establish a nonlinear,non-steady-state creep model for red-layered mudstone.Finally,parameters of the model were estimated and compared with the experimental results to verify the applicability of the theoretical model.The results show that at lower stresses,the rock samples mainly exhibit decay creep,in which creep deformation accounts for 85%of the total deformation.At higher stresses,the rock samples will undergo the whole process of creep from decay creep,steady state creep to accelerated creep,in which creep deformation accounts for 87%of the total deformation.The shear stress has a significant effect on the creep deformation of rock samples.The higher the shear stress,the longer the time required for decay creep to reach the steady state,and the higher the proportion of creep deformation in the total deformation.In the whole process of creep,the creep deformation of rock samples is dominated by steady-state creep,whose creep time accounts for 80%of the total creep time,and creep deformation accounts for 51%of the total creep deformation.The model can completely describe the whole process of creep from decay to steady state and to accelerated creep of the rock sample.At the same time,it overcomes the problem that the parameter values of the traditional model keep changing with the stress level.The creep deformation characteristics of the rock sample in each stress state can be described by one set of parameters.The results obtained from the theoretical model are in good agreement with those of the experiment,indicating that the proposed model has good applicability to the red-layered mudstone in Central Yunnan.关键词
滇中红层泥岩/蠕变特性/非定常加速元件/非线性蠕变模型/参数辨识Key words
red-bed mudstone in Central Yunnan/creep characteristics/unsteady acceleration element/nonlinear creep model/parameter identification分类
建筑与水利引用本文复制引用
李宁,张茂建,张慧莉,徐诚,汪波..滇中红层泥岩剪切蠕变特性及其本构模型[J].中南大学学报（自然科学版）,2024,55(9):3520-3529,10.基金项目
国家自然科学基金资助项目(40872179,U1765110) （40872179,U1765110）
上海市自然科学基金资助项目(16ZR1423300)(Projects(40872179,U1765110)supported by the National Natural Science Foundation of China （16ZR1423300）
Project(16ZR1423300)supported by Natural Science Foundation of Shanghai) （16ZR1423300）
