摘要
针对某工程砂砾料开展了大型三轴流变试验研究,获得了砂砾料流变变形的基本规律,探讨了流变变形速率发展特征及其与围压、应力水平的关系。在双对数坐标中,初期流变速率随时间非线性减小;随着时间的发展流变速率与时间的关系逐步稳定为线性关系。在同一围压下,体积流变速率随时间发展规律基本一致,受应力水平的影响较小;应力水平越大,剪切流变速率初值越大,双对数坐标中不同应力水平下的剪切流变速率—时间曲线斜率基本一致。同一应力水平下,不同围压体积流变速率随时间发展趋势基本一致,但围压越高体积流变速率数值越大;剪切流变速率随时间发展趋势也基本一致,围压越高剪切流变速率数值越大。借鉴Mitchell一维流变速率模型,对体积流变速率与剪切流变速率随时间发展的规律建立了数学模型,提出了基于流变速率的三维流变模型。
Creep behaviors of sandy gravel at fixed loading were studied by large scale triaxial creep test in which incremental deviatoric stress was applied level by level.The basic law of creep deformation for gravel was obtained.The relationship between the development characteris⁃tics of the creep deformation rate,as well as its relation to the confining press and deviator stress level was discussed.In logarithmic coordi⁃nates of creep velocity and time,the creep velocity always decreased with time.At initial time,the relationship of logarithm of creep velocity and logarithm of time was nonlinear.As the time increased to a certain degree,the relationship between logarithm of creep rate and time grad⁃ually stabilized as a linear relationship.Under the same pressure,the development rate of volumetric strain at different deviator stress levels was similar.There was no evident effect of stress level on volumetric strain velocity.However,the stress level had effect on shear strain rate.The higher the stress level,the higher the initial value of the shear creep velocity.The slope of the creep shearing strain rate⁃time curves with different in double logarithmic coordinates were almost the same.Under the same stress level,the development trend of creep rate of volumet⁃ric strain with time was similar.However,the higher the confining pressure,the greater the volume creep velocity.The development trend of shear creep rate was also basically consistent.The higher the confining pressure,the greater the shear creep rate.With reference to the one⁃dimensional creep rate model proposed by Mitchell,the mathematical rule of the creep rate of volumetric strain and shear strain was estab⁃lished.A three⁃dimensional creep model based on creep velocity was proposed.
作者
张茵琪
邓刚
张延亿
陈辉
边京红
ZHANG Yinqi;DENG Gang;ZHANG Yanyi;CHEN Hui;BIAN Jinghong(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)
出处
《人民黄河》
CAS
北大核心
2021年第2期116-121,共6页
Yellow River
基金
国家重点研发计划项目(2017YFC0404803)
中国水科院基本科研业务费专项(GE0145B562017,GE0145B102020)。
