摘要
分级加载的流变试验方法采用单个岩样进行试验,可避免岩样离散性对流变变形的影响,但后级载荷的变形量包含前面各级载荷产生的蠕变变形,很容易引起混淆。详细分析流变介质对加载历史的记忆效应,并给出考虑加载历史的蠕变数据处理的具体步骤和数学依据。同时,对大岗山水电站坝基辉绿岩三轴流变试验曲线进行整理,分析其典型的流变特性。根据不同应力水平下的蠕变试验曲线,提出由瞬弹性Hooke体、黏弹塑性村山体、非线性黏塑性体串联而成的岩石非线性黏弹塑性流变模型。该流变模型通过引入非线性黏塑性体可以描述岩石流变的减速、等速特别是加速蠕变阶段。推导非线性黏弹塑性模型的三维蠕变方程,利用不同应力水平下岩石蠕变试验曲线,对流变参数进行反演。结果表明,非线性流变模型计算曲线与试验曲线较吻合,证实所建模型的正确性与合理性。
Single specimen is used for rheological test method under multistep loading,which avoids the discrete affection of specimen for rheological deformation.But the deformation of the later loading contains the creep deformation induced by the former loading of all levels by this method,which always makes people confused.The memory effect of loading history for the rheological media is analyzed detailedly;and the concrete steps and mathematical basis of the data processing are proposed.Based on the triaxial rheological test results of diabase in dam foundation of Dagangshan hydropower station,the typical character of rheological curves is analyzed.According to loading creep test curves under different stress levels,by connecting the instantaneous elasticity Hooke body,visco-elastoplastic Schiffman body and nonlinear viscoplastic body in series,a new nonlinear visco-elastoplastic rheological model of rock is proposed.Through introducing the nonlinear viscoplastic component,this rheological model can describe the transient creep stage,steady-state creep stage and tertiary creep stage.Three-dimensional rheological and creep equations under constant stress are deduced.On the basis of complete creep curves gained by rheology equipment,the rheological parameters are inversed.The comparison between nonlinear rheological model and experimental curves shows that two curves accord well with each other,and the proposed nonlinear visco-elastoplastic rheological model is available and reasonable.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2011年第7期1405-1413,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展规划(973)项目(2009CB724607)
国家自然科学基金资助项目(40772173)
教育部新世纪优秀人才支持计划资助项目(NCET–08–0336)
关键词
岩石力学
辉绿岩
非线性流变模型
参数反演
加载历史
蠕变方程
rock mechanics
diabase
nonlinear rheological model
parameters inversion
loading history
creep equation
