考虑弱化特性的风积土动应力-应变关系研究  

Study on dynamic stress-strain relationship of aeolian soil considering degradation of stiffness

作　　者：宋洋[1] 张向东[1] 

机构地区：[1]辽宁工程技术大学土木与交通学院,辽宁阜新123000

出　　处：《地震工程与工程振动》2013年第6期236-243,共8页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(50978131);辽宁省高等学校优秀人才支持计划项目(2008RC23)

摘　　要：以辽西地区京沈高速铁路途径段风积土为研究对象,通过循环三轴试验,研究了风积土在不同固结条件和施加初始静偏应力作用下刚度的循环弱化特性,提出了考虑有效固结应力、初始静偏应力、动应力水平和循环次数影响因素的风积土刚度弱化模型。结果表明:在相同固结条件下,风积土的刚度随固结围压的增大而增大;循环次数的增加、初始静偏应力的施加和动应力比的提高,使风积土的刚度衰减显著;在试验的基础上提出了风积土在循环荷载作用下刚度弱化模型,利用该模型并结合修正Masing准则对风积土的动应力-应变关系进行描述。A series of triaxial tests were performed on aeolian soil. The degradation characteristics under different consolidation conditions and initial static deviator stiffness were analyzed and a stiffness degradation model consider- ing effective consolidation stress, initial static deviator stress, dynamic stress and number of cycles was proposed. It was shown that in the same consolidation conditions, the stiffness increased with confining pressure increased. Pro- gressive number of cycles, initial deviator stress and dynamic stress ratio accelerate the degradation of stiffness. The stiffness degradation model is proposed on the basis of the test to better reflect the law of stiffness degradation. This relationship was synthesized in the form of an empirical equation, which was further used to describe the dynamic stress-strain relationship of aeolian soil according to modified Masing＇ s rule.

关 键 词：循环荷载 风积土 刚度 弱化 修正的Masing准则 

分 类 号：TU441[建筑科学—岩土工程] P315.93[建筑科学—土工工程]