摘要
为研究台阶式加筋土挡墙面板水平位移特征及其最大水平位移与稳定性的量化关系,采用验证的有限差分数值方法确定挡墙面板水平位移和每层筋材最大拉力,并借助强度折减方法确定相应挡墙的稳定系数,进而参数化分析填土及地基土性质、筋材性质和分级模式对面板水平位移及挡墙稳定性的影响,结果表明:(1)针对两级加筋土挡墙,保持其他参数不变:增加填土内摩擦角φ或黏聚力c,挡墙自稳能力增强,最大水平位移和实际筋材最大拉力均明显减少;增加上级或下级挡墙筋材长度,面板最大水平位移呈减少趋势,挡墙稳定系数相应增加,当上级筋材长度为0.7H(H为总墙高)和下级筋材长度为0.6H时,挡墙变形和稳定系数趋于稳定;减少筋材层间距或增加筋材刚度,挡墙最大水平位移减小,而稳定系数相应增加。(2)针对各级挡墙均分总墙高的台阶式加筋土挡墙,增加台阶宽度,面板最大水平位移先减小后渐趋稳定,对于规范推荐的填土(φ=34°),确定相邻两级挡墙互不影响的临界台阶宽度为1.2倍分级墙高。(3)当台阶式加筋土挡墙总墙高和相对台阶宽度不变时,增加分级数导致最大水平位移和稳定系数均呈先减少后增加的趋势;两级加筋土挡墙上、下级墙高比不大于1时,墙高比变化对面板位移影响小;增加总墙高导致面板最大水平位移明显增加,稳定系数减少。(4)针对两级台阶式加筋土挡墙,建立了稳定系数、最大水平位移及台阶宽度的函数关系式,为实践中基于面板最大水平位移量化指标评估加筋土挡墙稳定性提供了有益参考。
To investigate the behavior of lateral facing deformation of a geosynthetic-reinforced soil(GRS)wall in a tiered configuration and to quantify the correlation between the maximum lateral facing deformation and the factor of stability(FS)of the corresponding wall,a validated finite difference numerical method was used to calculate the lateral facing deformation and the maximum tensile force mobilized in each layer reinforcement,which were inputted in the shear strength reduction(SSR)method to determine the factor of safety of the tiered GRS walls.Further,a parametric study was performed to analyze the effect of properties of backfill and foundation soil,reinforcement properties,and configuration mode of the tiered GRS walls on the lateral facing deformation and the factor of stability.The results show that:(1)for the two-tiered GRS walls with other parameters remaining constant,an increase in friction angle or cohesion of the backfill causes the enhancement of the wall stability,and thus decreases the maximum lateral facing deformation and the maximum tensile forces mobilized in the reinforcement layers.Increasing reinforcement length in upper or lower wall results in a reduction of lateral facing deformation and an increase of FS.When the reinforcement length in upper or lower wall reach the critical value,e.g.0.7H(H is the total wall height)or 0.6H,the maximum lateral facing deformation and F_(S)value tend to be stable.Besides,reducing the vertical spacing of reinforcement or increasing the reinforcement stiffness causes a decrease in lateral facing deformation and an increase in FS.(2)Increasing the offset distance for a multitiered GRS wall with equally individual wall height,the maximum lateral facing deformation tends to decrease and then to be stable.The critical offset distance,beyond which each tier wall functions independently,is determined to be the 1.2 times the individual wall height for the backfill with a recommended friction angle φ=34°by guidelines.(3)The maximum lateral facing deformation and t
作者
高珊
肖成志
丁鲁强
于洪兴
GAO Shan;XIAO Chengzhi;DING Luqiang;YU Hongxing(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Tianjin Highway Development and Service Center,Tianjin 300170,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第1期235-245,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41877255,52078182)
天津自然科学基金项目(20JCYBJC00630)。
关键词
土力学
台阶式加筋土挡墙
筋材
面板水平位移
稳定性
数值方法
soil mechanics
tiered GRS wall
reinforcement
lateral facing deformation
stability
numerical analysis method
