循环荷载下原状结构红粘土累积塑性应变模型  

Accumulated plastic strain models of red clay in original structure under cyclic loading

作　　者：刘晓红[1] 方薇[2] 杨果林[3] 

机构地区：[1]湖南理工学院土木建筑工程学院,湖南岳阳414000 [2]长沙理工大学交通运输工程学院,湖南长沙410004 [3]中南大学土木工程学院,湖南长沙410075

出　　处：《水文地质工程地质》2013年第2期56-62,共7页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金资助项目(50778180);湖南省教育厅科研项目(11C0619)

摘　　要：基于循环荷载作用下原状结构红粘土εp-lgN试验曲线簇,采用经典的对数函数模型对稳定性曲线、Monismith指数函数模型对破坏型曲线进行拟合分析,获得了相应模型参数的拟合公式,得出发散型对数函数模型不适宜于稳定型曲线的结论。针对稳定型曲线收敛的特点,提出了一个新的稳定型曲线累积塑性应变数学模型。与发散型对数函数模型比较,新模型具有收敛性,能更好地模拟稳定型曲线的变化规律。利用新模型对不同试验条件下原状结构红粘土稳定型曲线进行拟合,获得了新模型参数拟合公式。基于原状结构红粘土临界动应力试验值,引入了一个新的参数"动应力比",该参数的引入能很好地降低试验数据点的离散性。Based on the εp-lgN test curves of red clay in original structure under cyclic loading,the classical models are applied in fitting analysis for logarithmic function to stable type curve and Monismith exponential function to destructive type curve.The fitting formulas of each model parameter is obtained,and the conclusion is drawn that divergent logarithmic function model is not suitable for the stable type curve.In view of the convergence of the stable type curve,a new mathematical model of accumulative plastic strain for the stability curves is proposed.Compared with the divergent logarithmic function model,the new model is of convergence and can better simulate the change regularity of the stable type curve.By utilizing the new model to fit the stable type curves of red clay in original structure under different experimental conditions,fitting formulas of the new model parameters are obtained.Based on the critical dynamic stress test values of red clay in original structure,a new parameter called 'dynamic stress ratio' is introduced,which can reduce the discreteness of test data points.

关 键 词：累积塑性应变 数学模型 动应力比 循环荷载 原状结构红粘土 

分 类 号：TU435[建筑科学—岩土工程]