压扭耦合作用下粉砂土的双向动模量与阻尼比研究  

Bidirectional dynamic modulus and damping ratio of silt sand under compression and torsion coupling actions

作　　者：杨利国 邵生俊[1,3] YANG Liguo;SHAO Shengjun(Institute of Geotechnical Engineering,Xi'an University of Technology,Xi'an,Shaanxi 710048,China;Yellow River Conservancy Technical Institute,Kaifeng,Henan 475003,China;Shanxi Key Laboratory of Loess Mechanics and Engineering,Xi'an University of Technology,Xi'an,Shaanxi 710048,China)

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048 [2]黄河水利职业技术学院,河南开封475003 [3]西安理工大学陕西省黄土力学与工程重点实验室,陕西西安710048

出　　处：《岩石力学与工程学报》2020年第10期2104-2114,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41272320,11572245)。

摘　　要：为了研究振动频率和相位差对粉砂土双向动模量和阻尼比的影响,利用空心圆柱扭剪仪进行了一系列轴向与扭转向双向动荷载耦合作用的试验。结果表明:双向动荷载耦合作用下,振动频率和相位差对轴向动应力-应变关系曲线和扭转向的剪应力-应变关系曲线均有一定影响。振动频率和相位差对粉砂土的动剪切模量没有影响,只是相位差q=90°的初始动剪切模量最大。振动频率和相位差对粉砂土动压缩模量有一定影响,同一动应变处的动压缩模量随振动频率的增加先增大后减小,相位差q=0°时动压缩模量最大,q=90°的最小。振动频率对于粉砂土的动剪切阻尼比和动压缩阻尼比均没有影响,但是相位差对动剪切阻尼比和动压缩阻尼比都有较显著的影响,达到相同剪应变时,q=0°和180°时的动剪切阻尼比基本重合且明显高于q=90°的动剪切阻尼比;而相位差q=90°时的动压缩阻尼比在动应变达到0.1%之后增加较快,显著大于其他相位差的阻尼比。In order to study the effect of the vibration frequency and the phase difference on the two-way dynamic modulus and the damping ratio of silt sand,a series of tests under the action of compression and torsion coupling were conducted using the hollow cylindrical torsion shear apparatus.The results show that,under the coupling action of two-way dynamic loads,the vibration frequency and the phase difference have certain effects on the axial dynamic stress-strain relationship and the torsional shear stress-strain relationship while no effect on the dynamic shear modulus of silt sand.The initial dynamic shear modulus with the phase difference q=90°is the largest.The vibration frequency and the phase difference have a certain effect on the dynamic compression modulus of silt sand.The dynamic compression modulus at the same dynamic strain increases firstly and then decreases with increasing the vibration frequency.The dynamic compression modulus is respectively the largest and the smallest when he phase difference q=0°and q=90°.The vibration frequency has no effect on the dynamic shear damping ratio and the dynamic compression damping ratio of silt sand,but the phase difference has a significant effect on them.When the same shear strain is reached,the dynamic shear damping ratios when q=0°and q=180°basically coincide with each other and are significantly higher than the dynamic shear damping ratio as q=90°.The dynamic compression damping ratio at a phase difference q=90°increases faster after the dynamic strain reaches 0.1%,significantly greater than the damping ratio of other phase differences.

关 键 词：土力学 压扭动荷载 耦合 粉砂土 动模量 阻尼比 

分 类 号：TU43[建筑科学—岩土工程]