基于三相孔隙介质模型的地震动传播特性研究  

Ground motion propagation characteristics based on three-phase porous medium model

作　　者：杨艳霜[1] 闫磊 张占荣[2] 刘永莉[1] 崔臻[3] 彭剑承 亢兆鹏 YANG Yan-shuang;YAN Lei;ZHANG Zhan-rong;LIU Yong-li;CUI Zhen;PENG Jian-cheng;KANG Zhao-peng(Key Laboratory of Intelligent Health Perception and Ecological Restoration of Rivers and Lakes of Ministry of Education,Hubei University of Technology,Wuhan,Hubei 430068,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan,Hubei 430063,China;State Key Laboratory of Geomechanics and Geotechnical Engineering Safety,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]湖北工业大学河湖健康智慧感知与生态修复教育部重点实验室,湖北武汉430068 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063 [3]中国科学院武汉岩土力学研究所岩土力学与工程安全全国重点实验室,湖北武汉430071

出　　处：《岩土力学》2025年第4期1109-1121,共13页Rock and Soil Mechanics

基　　金：湖北省重点研发计划(No.2023BAB093);中铁第四勘测设计院科技研发项目(No.KY2023019S);中国铁建股份有限公司科技重大专项(No.2024W01)。

摘　　要：研究地震动在软土层中的传播特性对建筑物抗震设防具有重要现实意义。根据地震动在离心振动台试验中的衰减特性,将获取的土样重塑成35%、45%、55%含水率的土样并进行常规物理试验。通过宏细观参数对比来设定模型中颗粒之间的团簇形态和颗粒之间黏结的切法向刚度、摩擦系数、泊松比、阻尼比等参数,并引入质量阻尼β_(n)和刚度阻尼k_(n)来限制颗粒的运动状态,调节颗粒运动中的碰撞。依据不同含水率常规物理试验结果修正三相孔隙介质地层模型的细观参量,以研究在地震荷载下不同含水率的软土对峰值加速度传播衰减效应的影响。研究结果表明,在不同地震动条件下,峰值加速度在30m深度段,软硬分层土质中呈现出先缓慢衰减后急剧衰减再回弹上升的变化规律。随着含水率增加,深度30~8m地层内峰值加速度衰减倍率在2.33~2.70区间内增加;而深度8~0m地层对应放大倍率则在1.60~1.23区间内减小。反应谱周期0.2~1.1s对应中低频率范围,加速度值呈现增加趋势,在周期1.1~2.0s内对应的是高频率范围,加速度值普遍呈现减小趋势,这与高频衰减效应一致。通过数值模拟与理论分析对比验证,初步探明了不同含水率条件下地震动在近地表的传播放大规律,为评估地震灾害风险及提升地震防护提供了理论依据。The propagation characteristics of seismic waves in soft soil are crucial for enhancing the seismic resilience of buildings.By analyzing the attenuation properties of dynamic peak acceleration(PGA)through centrifugal vibration table tests,we aim to enhance our understanding of the impact of soil properties on seismic wave propagation.To accomplish this,we adjust the obtained soil samples to moisture contents of 35%,45%,and 55%and perform conventional physical tests.Subsequently,the cluster morphology and tangential stiffness of particle bonding within the model will be determined by macro-micro parameters,including friction factor,Poisson ratio,and other critical factors like the damping ratio.Additionally,both the mass damping β_(n) and the stiffness damping k_(n) will be meticulously examined as they regulate particle motion and collisions.According to the results of the conventional physical test of the different moisture contents,the effect of soft soil on the decay effect of PGA under different moisture content conditions are studied.The research results show that under different ground motion conditions,the peak acceleration in soft and hard layered soil at a depth of 30 m presents a change law of slow attenuation,sharp attenuation and then rebound rise.With the increase of water content,the attenuation ratio of peak acceleration in the depth of 30 m to 8 m increases in the range of 2.33 to 2.70.The corresponding magnification of 8−0 m depth strata decreases in the range of 1.60−1.23.The period of the response spectrum 0.2−1.1 seconds corresponds to the middle and low frequency range,and the acceleration value shows an increasing trend;the higher frequency range corresponds to the period 1.1−2.0 seconds,and the acceleration value generally shows a decreasing trend,which is consistent with the high-frequency attenuation effect.Through comparison and verification of numerical simulation and theoretical analysis,the law of ground motion propagation and amplification near the surface under different wa

关 键 词：地震波 放大效应 离散元 峰值加速度 含水率 

分 类 号：TU445[建筑科学—岩土工程]