单、双排桩支护路堑边坡动力响应特性的振动台试验研究  

Shaking table experimental study on the dynamic response characteristics of single and double-row pile-supported road graben slopes

作　　者：朱丹 蒋关鲁[1,2] 陈虹羽[1,2] 赵鑫辉[3] 黄德贵 刘乙甫 ZHU Dan;JIANG Guan-lu;CHEN Hong-yu;ZHAO Xin-hui;HUANG De-gui;LIU Yi-fu(School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Key Laboratory of High-Speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Zhejiang Institute of Communications Co.,Ltd.,Hangzhou,Zhejiang 310012,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031 [3]浙江数智交院科技股份有限公司,浙江杭州310012

出　　处：《岩土力学》2024年第6期1763-1777,共15页Rock and Soil Mechanics

基　　金：国家重点研发计划“政府间国际科技创新合作”重点专项(No.2022YFE0104600);国家自然科学基金(No.52378463)。

摘　　要：结合西部艰险山区铁路实际工程背景,开展了El-Centro波作用下单、双排桩支护路堑边坡大型振动台模型试验,基于位移、加速度等参数深入研究了两种模型边坡动力响应特性的差异,并结合快速傅里叶变化(fast Fourier transform,简称FFT)谱探讨了两种边坡出现差异的原因。结果表明:抗滑桩的支护效果和差异均随输入波幅值的增大而逐渐体现;当输入波幅值为0.1g~0.3g时,单、双排桩边坡均处于稳定状态,总体动力响应特性差异较小;当输入波幅值为0.4g时,两边坡动力响应开始出现较大差异,单排桩边坡宏观破坏更明显,坡表位移增大较多,土体损伤累积,非线性特征显现;当输入波幅值为0.5g~0.6g时,两种模型边坡的地震波峰值加速度(peak ground acceleration,简称PGA)放大系数高程效应明显,且均在路堑面和桩后坡面处出现塑性区,抗滑桩的存在有效地抑制了PGA放大系数沿坡面向上的增大趋势和坡表双塑性区的贯通,而单排桩边坡PGA放大效应更明显,塑性区范围更广,深度更大,局部失稳更严重,抗震支护作用相对较弱;引入FFT谱比可知,单、双排桩边坡在5~10 Hz频段振幅放大效应的不同是造成单、双排桩边坡动力响应差异的主要原因;在地震作用下,单排桩边坡破坏历经边坡自稳定→坡表土体塑性变形→边坡局部塌陷溃散3个阶段,双排桩边坡破坏历经前两阶段。Considering the engineering background of the dangerous western mountain railroad,large-scale shaking table model experiments were conducted on embankment slopes supported by single and double-row piles,subjected to El-Centro wave excitations.Based on parameters such as displacement and acceleration,an in-depth investigation was conducted to study the differences in dynamic response characteristics between the two slope models.Moreover,the reasons for the differences between the two slopes were explored using fast Fourier transform(FFT)spectra.The results revealed that both the support effect and the differences in anti-slip piles gradually increased with the increase in the input wave amplitude.At input wave amplitudes of 0.1g−0.3g,both single and double-row pile slopes remained stable,with minimal differences in their overall dynamic response characteristics.However,at an input wave amplitude of 0.4g,significant differences in the dynamic responses of both slopes emerged.Macroscopic damage was more apparent in the single-row pile slope,with high slope surface displacement,accumulated soil damage,and noticeable nonlinear characteristics.At an input wave amplitude of 0.5g−0.6g,both slope models exhibited a pronounced“elevation effect”in the peak ground acceleration(PGA)amplification factor.Additionally,plastic zones were observed on the road cut face and behind the piles in both models.The presence of retaining piles effectively suppressed the upward trend of PGA amplification coefficients along the slope and prevented the connection of plastic zones on the slope surface.Notably,the PGA amplification effect of the single-row pile slope was pronounced,with a wide and deep plastic zone,severe local instability,and relatively weak seismic support effect.The introduction of the FFT spectral ratio revealed that the difference in amplitude amplification effects of single and double-row pile slopes in the 5−10 Hz band was the main reason for the difference in their dynamic responses.Under seismic loading,the f

关 键 词：路基工程 路堑边坡 单、双排抗滑桩 振动台试验 动力响应 

分 类 号：U213.1[交通运输工程—道路与铁道工程]