摘要
为系统研究地裂缝场地动力响应规律,以西安f地裂缝为背景,设计并完成地裂缝场地土体振动台模型试验,获得场地土体的动力特性变化规律、加速度响应分布规律以及地震损伤发展特征。运用数值计算方法,分析地质构造特征对地裂缝场地动力响应的影响规律。研究结果表明:地震作用下,上盘土体的地震响应比下盘更大,裂缝出现时间更早,破坏更严重;随着地震强度的增大,土体损伤加剧,刚度大幅退化,两盘土体的动力特性趋于一致,动力响应的“上下盘效应”也不再显著;加速度放大系数由土体底部到顶部逐渐增大,表现出明显的放大效应,但不同土层、不同地震波的放大程度不尽相同;地裂缝场地构造特征会影响地震波在土体介质中的传播方式,改变场地的振动特性。
To investigate the dynamic response of the site with ground fissures,the shaking table model test of the soil was designed and carried out,based on the site with ground fissures of fin Xi’an.Distribution law of the acceleration response,variations of the dynamic characteristics and seismic damage propagation of the model soil were obtained.Furthermore,by applying the numerical calculation method,the influence of geological structure on the dynamic response of the site with ground fissures was investigated.The results indicated that,the dynamic response of the hanging-wall is larger than that of the footwall under the earthquakes.The cracks of model soil of the hanging-wall appear earlier than that of the footwall,and the soil on the hanging-wall suffers more damage.With the increase of input seismic intensity,the damage degree of the model soil also increases,the stiffness may degenerate greatly,and the dynamic characteristics of the hanging-wall and footwall tend to be consistent so that the“hanging-wall and footwall effects”of dynamic response are no longer obvious.The amplification coefficients may increase with the burial depth,exhibiting remarkable amplification effects,but the amplification degree of different soil layers and different seismic waves are different.The structural characteristics of the site with ground fissures have an influence on the propagation mode of seismic wave in the soil medium,which may change the vibration characteristics of the site.
作者
张朝
熊仲明
原晓露
孟毅欣
韩志强
Zhang Chao;Xiong Zhongming;Yuan Xiaolu;Meng Yixin;Han Zhiqiang(School of Civil Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China;Academician Expert Workstation of Mine Safety and Underground Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China;Xi’an University of Architecture&Technology,Xi’an 710055,China;School of Materials and Metallurgy,Inner Mongolia University of Science&Technology,Baotou 014010,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2022年第7期90-97,107,共9页
China Civil Engineering Journal
基金
国家自然科学基金(51278399)
住建部自然基金(2019-k-044)
陕西省自然科学基础研究计划重点项目(2018JZ5008)。
关键词
地裂缝场地
振动台模型试验
数值模拟
动力响应
地震损伤
ground fissures site
shaking table model test
numerical simulation
dynamic response
seismic damage
