多级变幅动载下含细粒砾砂动力参数试验分析  

Experimental Analysis on Dynamic Parameters of Fine-Grained Sand under Multi-Level Variable Amplitude Dynamic Loading

作　　者：王家全[1,2] 祝梦柯 林志南 王晴 Wang Jiaquan;Zhu Mengke;Lin Zhinan;Wang Qing(College of Civil and Architectural Engineering,Guangxi University of Science and Technology,Liuzhou,Guangxi 545006,P.R.China;Geotechnical Disaster and Ecological Control Engineering Research Center of Guangxi Zhuang Autonomous Region,Liuzhou,Guangxi 545006,P.R.China;College of Civil Engineering,Tianping College of Suzhou University of Science and Technology,Suzhou 215009,P.R.China)

机构地区：[1]广西科技大学土木建筑工程学院,广西柳州545006 [2]广西壮族自治区岩土灾变与生态治理工程研究中心,广西柳州545006 [3]苏州科技大学天平学院土木工程学院,江苏苏州215009

出　　处：《地下空间与工程学报》2022年第6期1933-1941,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(41962017);广西自然科学基金重点项目(2022GXNSFDA035081,2019GXNSFBA245071);广西高等学校高水平创新团队及卓越学者计划项目(桂教人才[2020]6号);广西研究生教育创新计划项目(YCSW2021310);广西大学生创新创业训练计划资助项目(202210594057)。

摘　　要：为揭示细粒含量及荷载频率对饱和砾砂动力参数的影响,通过GDS动态三轴测试系统开展了一系列饱和砾砂动三轴试验,探究了不同细粒含量、荷载频率下砾砂动力参数的发展规律。试验结果表明:同一动应力作用下砾砂轴向累积应变随细粒含量、荷载频率的增加不断增大,而回弹模量随之减小,N=9 000时FC=15%试样轴向累积应变相比于细粒含量FC=0%上升了1.136倍,回弹模量为未掺细粒试样的82.06%。随着细粒含量、荷载频率及动应力幅值的提高,动孔隙水压力与振次的关系曲线经历峰值型—稳定型—增长型—衰减型的转变。细粒含量越高、荷载频率越大,土体刚度越小,能量耗散能力越强,抗震性能越好。In order to reveal the influence of fines content and load frequency on the dynamic parameters of saturated gravel sand, a series of dynamic triaxial tests on saturated gravel sand were carried out through the GDS dynamic triaxial test system to explore the development law of gravel sand dynamic parameters under different fines content and load frequency. The results show that: Under the same dynamic stress, the axial cumulative strain of gravel sand increases with the increase of fines content and load frequency, while the modulus of resilience decreases. When N=9 000, the axial cumulative strain of the FC=15% sample increases by 1.136 times compared with the fine particle content FC=0%, and the modulus of resilience is 82.06% of that of the sample without fine particles. With the increase of fine particle content, load frequency and dynamic stress amplitude, the relationship curve between dynamic pore water pressure and vibration frequency changes from peak type—steady type—growth type—decay type. The higher the fines content, the higher the load frequency, the lower the stiffness of the soil, the stronger the energy dissipation capacity, and the better the seismic performance.

关 键 词：砾砂 动力参数 细粒含量 荷载频率 多级加载 

分 类 号：TU43[建筑科学—岩土工程]