复杂应力条件下EPS颗粒轻质混合土的动模量和阻尼比特性  

Dynamic Modulus and Damping Ratio of EPS Bead Composite Soil under Complex Stress Conditions

作　　者：高洪梅[1] 陈瑞[1] 童飞[1] 陈国兴[1] 蔡骁[1] 

机构地区：[1]南京工业大学岩土工程研究所,南京210009

出　　处：《防灾减灾工程学报》2015年第2期166-172,198,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(5110907);中国博士后科学基金项目(2012M511260);河南省交通运输厅科技计划项目(2012PⅡ05)资助

摘　　要：目前EPS颗粒轻质混合土的动变形特性研究主要借助于常规的动三轴剪切试验,受仪器条件限制往往不能考虑EPS颗粒轻质混合土的复杂初始应力状态,也不能考虑复杂的应力路径,比如地震、波浪以及交通荷载等。针对这一问题,利用GDS空心圆柱扭剪仪,考虑复杂初始应力状态,研究交通荷载作用下EPS颗粒轻质混合土的动变形特性,分析EPS颗粒体积比Ve/Vs、初始平均有效固结压力p0、初始固结应力比R0、初始中主应力系数b0和初始大主应力方向角α05个因素对EPS颗粒轻质混合土的动模量和阻尼比特性的影响。试验结果表明:Ve/Vs对试样动力变形特性的影响与p0有关;在相同应变水平下,随着R0增大,试样的动模量增大,而阻尼比变化不大;p0对试样动力变形特性有显著影响,相比之下α0和b0的影响较小。At present, the experimental research on the dynamic deformation behavior of EPS composite soil is restricted to the conventional dynamic triaxial shear test. The complex initial stress conditions and stress paths induced by the earthquake, wave and traffic loadings can not be considered because of the poor instrument conditions. Aiming at this issue, the dynamic deform- ation behavior of EPS bead composite soil subjected to the traffic loading was studied in consider ation of complex initial stress conditions through the GDS hollow cylinder torsional shear appara- tus. The influences of the following five factors on the dynamic modulus and damping ratio of EPS bead composite soil were analyzed. The factors are volume ratio of EPS heads to the soil Ve/Vs, initial average effective consolidation pressure Po, initial consolidation stress ratio Ro, initial intermediate principal stress coefficient bo, and initial principal stress direction angle αo. The re- suits indicate that the relationship between Ve/Vs and the dynamic deformation properties of the test soil is affected by the Po. The dynamic modulus of the test soil increase with Tnerease of Ro when it was subjected to the same dynamic strain, but Ro had a slight influence on the damping ratio of it. Compared with the αo and bo, the Po has a greater effect on the dynamic deformation properties of the test soil.

关 键 词：交通荷载 应力路径 轻质土 动模量 阻尼比 

分 类 号：TU411.8[建筑科学—岩土工程]