首页|循环荷载下镍铁渣-黏土的动力特性及本构模型

循环荷载下镍铁渣-黏土的动力特性及本构模型

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镍铁渣为一般的工业固体废弃物,经改良后可直接用作道路路基填料,但其动力特性尚值得深入研究.首先,通过筛分试验分析了纯镍铁渣的级配特征,提出了掺加黏土的改良方法,确定了黏土掺量和最优含水量;其次,开展了镍铁渣-黏土动三轴试验,获得了不同黏土掺量、压实度和围压下的动骨干曲线、动弹性模量.然后,通过镍铁渣路基原位试验及理论计算,得到了下路堤在运营期的沉降值.结果表明:纯镍铁渣为级配不良的砾砂,黏土掺量和含水率分别为35%和9%,试样的最大干密度最大;随着黏土掺量增加,镍铁渣-黏土颗粒之间的孔隙随之减小,对应的动强度和动弹性模量则均随之先增大后减小,黏土掺量为35%时,动强度和动弹性模量均最大;围压和压实度越大,镍铁渣-黏土之间作用力越强,动强度和动弹性模量也越大.基于Hardin-Drnevich模型和负幂律函数,建立了镍铁渣-黏土动应力-动应变拟合关系式及动弹性模量衰减模型,回归得到了拟合参数与黏土掺量、压实度及围压之间的关系式,并通过试验数据验证了其合理性.运营期镍铁渣-黏土路堤的沉降较小,满足路基设计要求.
Dynamic Characteristics and Constitutive Model of Ferronickel Slag-clay Under Cyclic Loading
Ferronickel slag is a general industrial solid waste,which can be directly used as roadbed filler after improvement,but its dynamic characteristics are still worthy of further study.Firstly,the grading characteristics of pure ferronickel slag were analyzed by screening test,and an improved method of adding clay was proposed to determine the optimal water content and clay content.Secondly,the dynamic triaxial test of ferronickel slag-clay was carried out,and the dynamic backbone curve and dynamic elastic modulus under different clay content,compaction degree and confining pressure were obtained.Lastly,through in-situ tests and theoretical calculations of the ferronickel slag subgrade,the settlement values of the lower embankment during operation period were obtained.The results show that the pure ferronickel slag is gravel soil with poor gradation,and the maximum dry density of the sample with 35%clay content and 9%water content is the largest.With the increase of clay content,the porosity between ferronickel slag and clay particles decreases,and the corresponding dynamic strength and dynamic elastic modulus increase first and then decrease.When the clay content is 35%,the dynamic strength and dynamic elastic modulus are the largest.The greater the confining pressure and degree of compaction,the stronger the interaction between ferronickel slag and clay,and the greater the dynamic strength and dynamic elastic modulus.Based on Hardin-Drnevich model and negative power law function,the dynamic stress-dynamic strain fitting relationship and dynamic elastic modulus attenuation model of ferronickel slag-clay were established.The relationship between fitting parameters and clay content,compaction degree and confining pressure was obtained by regression,and its rationality was verified by experimental data.During the operation period,the settlement of the ferronickel slag-clay embankment is small,which meets the design requirements of the subgrade.

subgrade engineeringdynamic modulus of elasticitydynamic triaxial testferronick-el slagdynamic shaft curve

尹平保、邹敏、贺炜、杨铠波、张永杰、李鑫、陈彦虎、张晓曦

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长沙理工大学特殊环境道路工程湖南省重点实验室,湖南长沙 410114

长沙理工大学土木工程学院,湖南长沙 410114

广东广青金属科技有限公司,广东 阳江 529533

中冶成都勘察研究总院有限公司,四川成都 610023

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路基工程 动弹性模量 动三轴试验 镍铁渣 动骨干曲线

国家自然科学基金国家自然科学基金湖南省教育厅科研项目特殊环境道路工程湖南省重点实验室开放基金湖南省研究生科研创新项目

521783115217841620A001kfj180502CX20220876

2024

中国公路学报
中国公路学会

中国公路学报

CSTPCD北大核心
影响因子:1.607
ISSN:1001-7372
年,卷(期):2024.37(4)