摘要
为了研究马蹄形隧道在高速列车振动荷载作用下的动力响应特性,采用模型试验与数值模拟相结合的方法,以时域、频域分析为基础,采用频率响应函数和峰值振动加速度作为评价指标,分析了列车时速分别为300 km/h和350 km/h的单点振动荷载作用下的隧道结构动力响应规律。通过FLAC^3D计算软件建立三维数值模型,研究了高速列车移动荷载作用下隧道结构的动力响应特性。研究结果表明:在列车振动全频域扫频荷载作用下,隧道结构内部的动力响应不是沿隧道环向逐渐衰减,而是仰拱到拱脚处的响应出现一定的衰减,但拱腰到拱顶处却呈现出增大趋势;在40~200Hz频率范围内,圆形断面隧道结构的动力响应小于马蹄形断面隧道结构的动力响应,平均差值约为3.8 dB,表明隧道的断面形状对其结构的动力响应影响较大,在设计时应予以考虑;在列车移动荷载作用下,各监测点的加速度响应表现出明显的周期效应,列车经过时动力响应显著增大;移动荷载作用下隧道结构的峰值振动加速度较单点振动荷载作用下均有不同程度的增加,因此在研究列车振动荷载诱发的动力响应特性时应考虑列车的移动效应。
In this paper, both physical tests and numerical simulation were conducted to study the dynamic response characteristics of the tunnels with horseshoe cross-section under high-speed train loads. Based on time domain and frequency domain analysis, the frequency response function(FRF) and peak particle acceleration(PPA) are used as evaluation indicators. Under the train vibration loads, the dynamic response of tunnels is analyzed at the speeds of 300 km/h and 350 km/h in the physical tests, respectively. The numerical model is developed by FLAC^3D to study the dynamic response of the tunnel under moving loads of high-speed train. Results show that the dynamic response of the tunnel is not attenuated in the circumferential direction as the distance from the vibration source increases. The tunnel response shows a clear attenuation from the inverted arch to the arch. However, there is an increasing trend from the arch to the vault. The test results also show that dynamic response of the horseshoe cross-section tunnel is greater than dynamic response of the circular tunnel, and the average difference is about 3.8 dB in frequency range of 40-200 Hz. It indicates that the tunnel cross-section greatly affects the dynamic response of the tunnel, which should be considered in design. Furthermore, the PPA of the tunnel is the largest at the inverted arch under single-point excitation load. The peak acceleration is the smallest at the tunnel dome. The PPA of the tunnel at monitoring points shows obvious periodic effect under moving train loads of high-speed train. The PPA reaches the highest value when the train travels at the monitoring section. The PPA of the tunnel under moving train loads shows a clear amplification compared with tunnel response under the single-point excitation load. Therefore, it is important to consider the effect of moving trains when studying the tunnel dynamic behaviour under train induced vibration loads.
作者
杨文波
邹涛
涂玖林
谷笑旭
刘雨辰
晏启祥
何川
YANG Wen-bo;ZOU Tao;TU Jiu-lin;GU Xiao-xu;LIU Yu-chen;YAN Qi-xiang;HE Chuan(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第9期3635-3644,共10页
Rock and Soil Mechanics
基金
国家重点研发计划资助（No.2016YFC0802201）
国家自然科学基金资助项目（No.51678499）~~
