摘要
通过分析法向应力、干密度、土样尺寸对吹填粉砂土蠕变特性的影响,深入研究其固结蠕变特性。与Kelvin模型相比,采用Burgers体模型能够更合理地阐释吹填粉砂土的蠕变曲线;采用FLAC3D方法可开展吹填土蠕变过程的三维数值模拟。结果表明:吹填粉砂具有一定的蠕变特性,并可用幂函数描述应力-应变、应变-时间的关系;干密度一定时,法向应力愈大,初始应变愈大,达到稳定的时间愈长;法向应力一定时,干密度越大,初始变形越小,最终稳定所需时间越短;大尺寸试样(Ф200.0mm×H200.0mm)的瞬时变形与蠕变形率要比标准尺寸(Φ61.8mm×H20.0mm)大,稳定所需时间要长;此外,Burgers体模型模拟吹填粉砂土固结蠕变变形优于广义Kelvin模型并具有可行性。
The authors research the consolidation creep characteristics of dredger fill silty sand by analyzing the effect of normal stress,dry density and sample size on its creep behavior.In comparison to the Kelvin’s model,the Burgers’s model is more reasonable to interpret the creep curve of dredger fill silty sand,so the FlCD3D method is utilized to carry out the three-dimensional numerical simulation of its consolidation creep process.The results show that dredger fill silty sand exhibits certain creep behavior and the power functions can be used to describe the stress-strain relationship and strain-time relationship .For the given dry density,the larger the normal stress is,the larger the initial strain is and the longer time it takes to stabilize.When normal stress is constant,the larger the dry density is,the smaller the initial deformation is and the shorter time it needs to stabilize eventually.The instantaneous deformation and creep rate of large size sample （Ф200.0 mm × H200.0 mm）is larger than that of standard size sample （Φ61.8 mm×H20.0 mm）and the time needed for larger size sample to stabilize is longer.In addition,the Burgers’s model proved to be superior to Kelvin’s model is feasible to simulate the consolidation creep process of dredger fill silty sand.The achievements of this research can provide helpful reference for simulations of creep test and engineering practices related to dredger fill silty sand in coastal area.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2014年第3期918-924,共7页
Journal of Jilin University：Earth Science Edition
基金
中央高校基本科研业务费专项基金项目(DUT12LK19)
国土资源部海洋油气资源与环境地质重点实验室开放基金(MRE201304)
岩土力学与深部地下工程国家重点实验室开放基金(SKLGDUEK1307)
