摘要
双面加筋路堤是一种较为新型的路堤形式,由于其优良的抗震性能而被越来越广泛地运用于道路建设工程中,而很多双面加筋路堤因工程建设需要分级设计为台阶型。然而国内外对该结构的抗震规律及性能的研究较少,且各类规范并未针对性提出明确的抗震设计方法。在前人的研究基础上,应用非线性动力有限元法分析了双级台阶式双面加筋路堤在地震作用下的响应特性。对填土应用小应变硬化土模型进行了模拟,在模型中考虑了模块面板间以及面板与土体之间的动力作用。为了深入理解加筋土结构的地震动力响应规律,选取了世界各地一类场地上的18条地震动作为地震输入,这些地震动的频谱特性和强度均有较大区别,但是地震的峰值加速度均调幅为0.4g(g为重力加速度)。结果表明:合理的台阶设置能有效减小结构震后变形,提高整体抗震稳定性;台阶式双面加筋路堤的地震位移模式主要受输入地震动频谱特性和结构自振频率性质的共同影响,台阶宽度的变化改变了结构质量及刚度的分布,一定程度影响了结构的振动形态。本研究建立起结构整体筋材最大拉力与输入地震动Arias强度(I_(A)^(input))、地震持续时间T_(d)、台阶宽度C、地震卓越频率f_(i)以及结构固有频率f_(r)的拟合关系式,从一个侧面定位了这些影响因素对双面加筋路堤抗震性能的影响。经过研究,在实际工程中应控制面板附近土体的压实度,使其满足工程要求,合理设置台阶和台阶宽度,可以减少路基在地震作用下顶部的不均匀沉降和面板的侧向位移;在路堤结构底部筋材拉力较大部分,可通过设置抗拉强度更大的筋带来增强整体结构的稳定性。研究结果可以为实际工程设计提供参考。
As a newly developed embankment type,back-to-back mechanically stabilized earth(MSE)walls have been increasingly used for the construction of roads and embankments in recent years due to their great earthquake-resistant performance,and a large number of these walls are built in tiered configurations to meet the needs of construction.However,the available literature on the seismic response of tiered back-to-back MSE walls is very limited,and existing design guidelines do not provide a clear earthquake-resistant design approach for these walls.Based on previous analysis,a finite-element procedure was used to simulate the seismic response of two-tiered back-to-back MSE walls under earthquake loading.In this study,the backfill soil was simulated using the hardening soil model with small-strain stiffness(HSS model),and the block-block,and soil-block interactions under earthquake loading were considered.To gain insight into the seismic behavior of reinforced soil structures,18 ground motion records at class I sites around the world were scaled to a peak acceleration of 0.4 g and employed as the excitation motions,which had very different frequency characteristics and earthquake intensities.The results showed that an appropriate tier offset decreased the residual deformations and effectively increased the seismic stability of the walls;the deformation mode for two-tiered back-to-back MSE walls subject to seismic loading was mainly influenced by the frequency characteristics of the input ground motion as well as the fundamental frequency of these walls,and the change in the distribution of structure mass and stiffness due to the change in tier offset modified the structural vibration mode to a certain extent.It was also found that there existed good correlations between the maximum reinforcement load and the Arias intensity(I_(A)^(input)),the duration T_(d),the tier off-set C,the predominant frequency f_(i)of the input ground motion,and the natural resonant frequency check spelling of the wall,which identified the influence of these factors on the earthquake-resistant performance of back-to-back MSE walls from one side.The research results can provide reference for practical engineering design.
作者
樊成
熊克健
刘杰
刘华北
Fan Cheng;Xiong Kejian;Liu Jie;Liu Huabei(School of Civil and Hydraulic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Science and Technology R&D Center,Xinjiang Transportation Planning,Survey and Design Institute Co.,LTD.,Urumqi 830006,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2023年第3期300-310,共11页
Bulletin of Geological Science and Technology
基金
国家自然科学基金项目(51669031)
新疆交通设计院科研基金项目(KY2019092504)
中央高校基本科研业务费(HUST:2020JYCXJJ047)。
关键词
台阶式双面加筋路堤
抗震性能
有限元分析
台阶宽度
筋材拉力
地震响应
tiered back-to-back mechanically stabilized earth(MSE)walls
earthquake-resistant performance
finite element analysis
tier offset
reinforcement load
seismic response
