摘要
三明治形加筋土挡墙作为一种新型的加筋土结构具有黏土的廉价、取材较方便、砂土界面剪切强度较高等优点。基于室内大型直剪仪研究了地震荷载作用下砂土与格栅界面的动力特性,通过回归分析得到了加筋土挡墙中筋土界面剪切刚度在动荷载作用下呈现剪切软化的变化规律经验公式;然后编制fish语言将该公式导入FLAC^3D软件中,建立了考虑筋土界面剪切刚度变化规律的三维计算模型,分析了加筋土挡墙的各种设计参数(挡墙的高度、筋材的长度、筋材的弹性模量、筋材的间距、面板的类型)对三明治形加筋土挡墙动力特性的影响。结果表明:加筋土挡墙的高度越高,面板的侧向位移越大;当峰值加速度为0.2 g(g为重力加速度)时,潜在破裂面交于墙顶接近0.36 H(H为挡土墙高),峰值加速度为0.4 g时,潜在破裂面交于墙顶接近0.47 H;筋材弹性模量的增大和筋材间距的减小能够增加挡墙的抗变形能力,且随着筋材长度的增加,面板最大水平位移逐渐减小;在两种峰值加速度下,模块式面板加筋土挡墙容易发生局部面板鼓胀破坏,而整体式面板加筋土挡墙容易发生整体倾倒破坏。
As a new type of reinforced soil structure,the sandwich reinforcement retaining wall has advantages with cheaper clay,convenient material extraction,and higher shear strength at the sand interface.The cyclic shear characteristics of the soil-geogrid interface were studied on a large direct shear apparatus.Through regression analysis,the empirical formula of shear stiffness softening of the interface under dynamic loads was proposed.Then the fish language of the empirical formula was compiled into the FLAC^3D software.A three-dimensional calculation model considering shear stiffness softening at the soil-geogrid interface was established.The influence of various design parameters of the retaining wall(the height of the retaining wall;the length,the spacing,and the modulus of the goegrid;and the type of the facing block)on the dynamic characteristics were analyzed.The results show that the higher the height of the retaining wall,the greater the lateral displacement of the facing block.When the peak acceleration was 0.2 g(g is the acceleration of gravity),the possible failure surface was 0.36 H(H is the heighth of retaining wall).When the peak acceleration was 0.4 g,the possible failure surface was 0.47 H.With increasing modulus or decreasing the spacing of reinforcement,the deformation of retaining wall decreased.With the increase of the length of the reinforcement,the maximum lateral displacement of the panel reduced.In addition,under the peak acceleration of 0.2 g and 0.4 g,the reinforced retaining wall with modular block facing was prone to local panel bulging damage,while the reinforced retaining wall with integral facing block was prone to overall collapse.
作者
齐添
应梦杰
刘飞禹
汪歆
陈加亮
QI Tian;YING Meng-jie;LIU Fei-yu;WANG Xin;CHEN Jia-liang(Guangzhou Environmental Protection Investment Group Co.,Ltd.,Guangzhou 510330,China;Department of Civil Engineering,Shanghai University,Shanghai 200444,China;Ningbo Communications Planning Institute Co.,Ltd.,Ningbo 315000,China)
出处
《科学技术与工程》
北大核心
2020年第25期10399-10406,共8页
Science Technology and Engineering
基金
国家自然科学基金(51678352,51878402)
宁波市交通运输委员会科技项目(201505)。
关键词
加筋土挡墙
地震荷载
剪切刚度软化
峰值加速度
模块式面板
reinforced retaining wall
seismic load
stiffness softening
peak acceleration
modular block facing
