煤渣改良土的阻尼比影响因素试验研究  

Experimental Study on Influencing Factors of Damping Ratio of Cinder Improved Soil

作　　者：张向东[1] 任昆 ZHANG Xiang-dong;REN Kun(School of Civil Engineering,Liaoning Technical University,Fuxin Liaoning 123000,China;School of Civil Engineering,Dalian Jiaotong University,Dalian Liaoning 116028,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]大连交通大学土木工程学院,辽宁大连116028

出　　处：《公路交通科技》2019年第10期43-51,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51774166);高等学校博士学科点专项科研基金联合资助项目(20112121110004)

摘　　要：为研究循环荷载给煤渣改良土阻尼比带来的影响,利用GDS动态三轴测试系统对不同围压及频率下的煤渣改良土进行了动三轴试验,获得了煤渣掺量、围压及频率对改良土阻尼比的影响规律.根据影响形式的不同,借助修正的Hardin-Drnevich模型建立了阻尼比的增长模型,并确定了模型中各参数的物理意义.试验结果表明:随着荷载作用次数的增加,各组改良土试样的滞回曲线均逐渐由开口型向闭合型过度,滞回曲线所围成的面积也逐渐减小;改良土滞回曲线所围成的面积随煤渣掺量的增加而逐渐增加,曲线的不闭合程度逐渐增大;当煤渣掺量及加载频率一定时,随着围压的增大,滞回曲线所围成的面积逐渐减小;当煤渣掺量与围压一定时,随频率的增加,改良土滞回曲线围成的面积逐渐减小,低频的作用较为明显;随着动应变的增大,改良土的阻尼比也逐渐增大,其增长速率出现先增大后减小的变化规律;煤渣掺量及围压是最大阻尼比的主要影响因素,随着煤渣掺量的增加,改良土的阻尼比逐渐增大,而围压的影响与之相反;频率主要影响阻尼比的增加速率且低频的影响较为突出.借助修正的Hardin-Drnevich模型所建立的阻尼比增长模型能够较好地反映阻尼比在加载过程中的变化趋势,具有较高的精度,可以为类似工程提供参考.In order to study the influence of cyclic loading on the damping ratio of cinder improved soil, the dynamic triaxial test on the cinder improved soil under different confining pressures and frequencies is carried out by using G D S dynamic triaxial testing system, and the influence rules of cinder content, confining pressure and frequency on the damping ratio of the improved soil are obtained. The growth model of damping ratio is established by the modified Hardin - Drnevich model according to the different influence forms, and the physical meanings of parameters in the model are determined. The experimental result shows that ( 1) with the increase of loading times, the hysteretic curve of each group of improved soil samples gradually transits from open to closed, and the area enclosed by the hysteretic curve gradually decreases;(2) the area enclosed by the improved soil hysteresis curve increases gradually with the increase of cinder content, and the unclosed degree of the curve increases gradually;(3) when the cinder content and the loading frequency are constant, the area enclosed by the hysteresis curve decreases gradually with the increase of confining pressure;(4) when the cinder content and the confining pressure are constant, the area enclosed by the hysteresis curve of the improved soil gradually decreases with the increase of frequency, and the effect of low frequency load is more obvious;(5) the damping ratio of the improved soil gradually increases with the increase of dynamic strain, its growth rate increases at first and then decreases;(6) cinder content and confining pressure are the main influencing factors of maximum damping ratio, the damping ratio of the improved soil increases gradually with the increase of cinder content, while the influence of confining pressure is opposite;(7) frequency mainly affects the increasing rate of damping ratio, and the influence of low frequency is more prominent. The established damping ratio growth model based on the modified Hardin- Dmevich model can better re

关 键 词：道路工程 阻尼比 动三轴试验 滞回曲线 煤渣 修正Hardin-Drnevich模型 

分 类 号：U416.25[交通运输工程—道路与铁道工程]