基于状态参量的饱和砂土剪胀性本构模型  

A dilatancy constitutive model of saturated sands based on state parameter

作　　者：赵春雷[1] 赵成刚[1] 张卫华[2] 高志华 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京城市学院城建学部,北京100086 [3]汉嘉设计集团股份有限公司北京分公司,北京100022

出　　处：《北京交通大学学报》2014年第1期99-102,共4页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家自然科学基金资助项目(51278047)

摘　　要：现有的边界面模型多用临界状态区分松砂、密砂,但试验中,很难确定密砂的临界状态.本文以相变线(PTL)为参考线,引入以相变状态为基础的状态参量,将已有的边界面模型加以改进利用状态参量的概念,可以准确判断砂土在初始时刻和任意时刻的变形趋势,而基于状态参量的剪胀比在相变点处仍等于零.无论是松砂还是密砂,或砂土从一种状态到另一种状态,基于状态参量的剪胀都能真实的模拟砂土的反应.研究结果表明,利用本文的模型参量得到的密砂三轴排水试验,模拟结果与试验结果相吻合,较好地反映了砂土的力学特征.In this paper,an existing bounding-surface is modified and a state parameter based on phase transformation state is introduced.The deformation tendency of a sand at any time or any conditions can be judged correctly by state parameter.As a result,the dilatancy depends on the state in a way that yields a zero value at phase transformation state.This dependence allows a realistic modelling of the response of a sand in either loose or dense state,or in the transition from one state to another state.A comparison between model simulations and a sequence of experimental results for drained,monotonic loading conditions shows that the simulation results are consistent with the test results,which can better reflect the mechanics characteristics of sandy soil.

关 键 词：饱和砂土 剪胀性 相变线 状态参量 

分 类 号：TU431[建筑科学—岩土工程]