不同含水率黔东南板岩蠕变试验及本构模型研究  

Study on Creep Test and Constitutive Model of Slate with Different Moisture Content in Southeast Guizhou

作　　者：李骏 LI Jun(Kaili Highway Administration Bureau of Guizhou Province,Kaili 556006,China)

机构地区：[1]贵州省凯里公路管理局,贵州凯里556006

出　　处：《粉煤灰综合利用》2022年第1期57-63,共7页Fly Ash Comprehensive Utilization

基　　金：贵州省交通运输厅科技项目(2020-123-003)。

摘　　要：为了解板岩的长期力学特性,对取自黔东南地区的板岩进行了不同含水率下的分级加卸载蠕变试验。结果表明:浸泡时间越长,含水率越高,板岩的软化损伤越严重,强度和弹性模量下降幅度越大;含水率越高,稳态蠕变率越大,且随应力增大呈幂函数增大特征;瞬时变形模量随应力增大呈先增大后减小变化特征,随含水率增大呈线性降低的变化特征,黏弹性应变和黏塑性应变也随含水率增大而逐渐增大;当经过长期浸泡后,板岩的长期强度有显著降低,0.15%、0.7%、1.2%和1.4%含水率下板岩的长期强度分别较短期强度下降14.7%、23.8%、24.1%和29.8%;在西原模型基础上,引入非线性黏塑性体,建立考虑含水率影响的蠕变模型,该模型可以对不同含水率不同阶段的蠕变变形特征进行较好描述,模型拟合数据与试验数据相关系数R^(2)>0.95。In order to understand the long-term mechanical properties of slate, the graded loading and unloading creep tests of slate from Southeast Guizhou under different moisture content are carried out.The results show that the longer the soaking time, the higher the moisture content, the more serious the softening damage of slate, and the greater the decrease of strength and elastic modulus;the higher the moisture content, the greater the steady-state creep rate, and it increases as a power function with the increase of stress;the instantaneous deformation modulus increases first and then decreases with the increase of stress, decreases linearly with the increase of water content, and the viscoelastic strain and viscoplastic strain also increase with the increase of water content;after long-term immersion, the long-term strength of slate decreases significantly.The long-term strength of slate at 0.15%,0.7%,1.2% and 1.4% moisture content decreases by 14.7%,23.8%,24.1% and 29.8% respectively compared with the short-term strength;based on the Xiyuan model, a nonlinear viscoplastic body is introduced to establish a creep model considering the influence of water content.The model can better describe the creep deformation characteristics at different stages of different water content.The correlation coefficient between the model fitting data and the test data is R^(2)> 0.95.

关 键 词：板岩 含水率 分级加卸载蠕变 瞬时变形模量 长期强度 模型 

分 类 号：TU458[建筑科学—岩土工程]