摘要
为了研究了循环动应力、初始静偏应力、固结比、振动频率共同作用对软黏土累积塑性应变的影响,以天津滨海新区临港工业区的浅海-滨海相软黏土为研究对象,利用GCTS循环扭剪三轴仪对其进行一系列循环三轴试验。试验结果表明,循环动应力增加、振动频率降低,能加快软化指数的衰减速率;初始静偏应力和固结比的增加,可提高软黏土抵抗循环动荷载的能力,减缓软化指数的衰减速率。综合考虑以上4种因素对软化指数随累积塑性应变发展变化的影响,总结得到了不同影响因素下软化指数与累积塑性应变之间的经验公式。结合以往学者对软化指数和循环荷载振动次数的相关性研究,以软化指数为桥梁,最终建立了针对天津滨海软黏土累积塑性应变的增长模型,并对模型的适用性进行了验证。
This paper investigates the combined effects of dynamic stress, initial static shear stress, consolidation ratio and vibration frequency on growth of accumulative plastic strain of soft clay located in Lingang industrial district, Tianjin Binhai New Area. A series of cyclic triaxial tests is conducted with continental facies soft clay samples by GCTS triaxial torsional shear apparatus. It is observed that when shear stress increases, the ability of resisting cyclic loading enhances, The decaying rates of softening index become slow at the same time. Consolidation ratio affects similarly on growth of accumulative plastic strain. Empirical formulation between softening index and accumulative plastic strain is established considering various influencing factors above-mentioned. Based on previous results, referring to the relationship between softening index and vibration times of cyclic loading N, a new accumulative plastic strain growth model is proposed for soft clay in Tianjin Binhai New Area, including four types of influence factors. And applicability of this model is verified.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第4期979-984,共6页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51179186
No.41372291)
天津市科技计划项目(No.15JCZDJC40600
No.15ZCZDSF00220)~~
关键词
循环荷载
累积塑性应变
软化指数
初始静偏应力
固结比
振动频率
cyclic loading
accumulative plastic strain
softening index
initial static shear stress
consolidation ratio
vibrationfrequency
