软黏土动力特性的试验研究  

Experimental study on dynamic characteristics of soft clay

作　　者：潘婧 PAN Jing(Nanjing Higher Vocational and Technical School,Nanjing 210000,Jiangsu,China)

机构地区：[1]南京高等职业技术学校,江苏南京210000

出　　处：《工程建设》2024年第12期35-39,共5页Engineering Construction

摘　　要：淤积滨海平原区软黏土为多种岩性岩相的沉积复合体,破坏应变较小且极易扰动,该类软黏土的动力特性仍未完全探明。现以诺软黏土为例,现场取样开展室内微机控制动三轴试验,对试样施加正弦波荷载,通过改变动应力大小、震动次数、围压,研究其动力特性。研究结果表明:动模量比RG随动剪应变rd成倍增减,在相同的动剪应变水平时,初始动模量随固结压力增加而增加;在相同动应力幅值作用下,随着循环周次的增加和动应力幅值增大,软黏土最大动应变也随之逐渐增大;当振动周次增加时,沉积土层动强度则相应减小;且土层动应力幅值σd随着固结压力σ3c的增大而逐渐增大;动内摩擦角随循环次数的增加而减小。The soft clay in the silted coastal plain area is a sedimentary complex of multiple lithology and lithofacies,with small failure strain and easy to be disturbed.The dynamic characteristics of this kind of soft clay have not been fully explored.Now,taking Nuoshan soft clay as an example,the indoor microcomputer⁃controlled dynamic triaxial test is carried out on the site,and the sine wave load is applied to the sample,and its dynamic characteristics are studied by changing the magnitude of dynamic stress,vibration times,and confining pressure.The results show that the dynamic modulus increases and decreases exponentially with the dynamic shear strain rd than RG.At the same dynamic shear strain level,the initial dynamic modulus increases with the consolidation pressure;Under the same dynamic stress amplitude,the maximum dynamic strain of soft clay will gradually increase with the increase of cyclic cycles and dynamic stress amplitude;When the vibration frequency increases,the dynamic strength of Lano sedimentary soil layer decreases correspondingly;And dynamic stress amplitude of soil layerσd with consolidation pressureσ3c increases gradually;The dynamic internal friction angle decreases with the increase of the number of cycles.The research results can improve the understanding of complex sedimentary dynamic characteristics.

关 键 词：软黏土 动力特性 动三轴试验 振动荷载 

分 类 号：TU435[建筑科学—岩土工程] TU41[建筑科学—土工工程]