摘要
群桩基础的横向动力响应一直是岩土工程抗震领域研究的热点问题,为此开展了干砂与饱和砂土场地条件下2×2直斜群桩的离心机振动台试验,然后基于FLAC3D软件引入砂土液化大变形本构建立三维数值模型,将试验结果与数值模拟结果进行对比验证,深入分析试验和模拟中直斜群桩横向动力响应规律。结果表明:在干砂场地中,直群桩承台加速度总大于斜群桩承台加速度;在饱和砂土场地中,直斜群桩承台加速度均出现了一定程度的衰减现象,而直群桩承台的加速度衰减现象较斜群桩承台更为明显;干砂场地中桩身弯矩随桩间距的增大而减小,饱和砂土场地中桩身弯矩随着桩间距的增加呈现先增大后减小的趋势;干砂场地中承台加速度相对于输入台面加速度的放大倍数小于1时所需的桩间距大于饱和砂土场地。
The lateral dynamic response of group pile foundation has been a hot issue in the field of geotechnical engineering seismic research.In this regard,the centrifuge shaking table test of 2×2 straight-sloping group pile under dry sand and saturated sand site conditions is carried out,then a three-dimensional numerical model is established based on the introduction of sand soil liquefaction large deformation ontology by FLAC3D software,and the test results are compared with the numerical simulation results for verification.The transverse dynamic response rule of straight inclined pilegroup in test and simulation is deeply analyzed.The results show that in dry sand site,the acceleration of straight group pile bearing is always larger than that of inclined group pile bearing.In saturated sand site,the acceleration of both straight and inclined group pile bearing decays to a certain extent,but the decay of acceleration of straight group pile bearing is more obvious than that of inclined group pile bearing.The pile bending moment decreases with the increase of pile spacing in dry sand site,and the pile bending moment increases with the increase of pile spacing in saturated sand site.The pile bending moment in the dry sand site decreases with increasing pile spacing,while the pile bending moment in the saturated sand site increases with increasing pile spacing and then decreases.The required pile spacing is greater for dry sand sites where the amplification of the bearing acceleration with respect to the input table acceleration is less than 1 for saturated sand sites.
作者
李雨润
范浩然
闫志晓
辛晓梅
LI Yurun;FAN Haoran;YAN Zhixiao;XIN Xiaomei(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Civil Engineering Technology Research Center of Hebei Province,Tianjin 300401,China)
出处
《自然灾害学报》
CSCD
北大核心
2024年第3期202-216,共15页
Journal of Natural Disasters
基金
国家自然科学基金项目(52278340,51778207)
河北省自然科学基金项目(E2023202028)
中国地震局工程力学研究所基本科研业务费专项资助项目(2021D02)
河北省研究生创新资助项目(CXZZSS2024009)。
关键词
饱和砂土场地
干砂场地
群桩基础
振动台试验
数值模拟
saturated sand site
dry sand site
group pile foundation
shaking table test
numerical simulation
