Experimental and numerical evaluation of the effectiveness of a stiff wave barrier in the soil
Experimental and numerical evaluation of the effectiveness of a stiff wave barrier in the soil
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DOI：
10.1016/j.soildyn.2015.04.007
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发表时间：
2015-10-01
影响因子：
4
通讯作者：
Lombaert, G.
中科院分区：
文献类型：
--
作者：
Coulier, P.;Cuellar, V.;Lombaert, G.
本文讨论了土体中刚性波障作为铁路诱发振动缓解措施有效性的设计、安装、实验和数值评价。在El Realengo（西班牙）的一个地点进行了一项全尺寸的现场实验，在那里沿铁路轨道安装了一个由重叠喷射灌浆柱组成的屏障。与土壤相比，这个屏障是坚硬的，深度为7.5米，宽度为1米，长度为55米。在安装屏障之前进行了地球物理测试，以确定土壤的动态特性。在安装屏障之前和之后都进行了大量的测量，包括火车通道期间的自由场振动，轨道和自由场之间的传递函数以及轨道接受度。为了验证列车、轨道和土壤条件随时间变化的影响，在与试验段相邻的参考段也进行了测量。现场测量表明，屏障是非常有效的：在火车通道期间，从8赫兹以上已经获得了5分贝的振动水平降低，而在屏障后面的30赫兹附近观察到约12分贝的峰值降低。在远离喷射注浆墙的地方，性能进一步下降，但仍然显著。并将实验结果与基于有限元-边界元耦合方法的数值模拟结果进行了比较。在实验和预测之间找到了合理的一致，在很大程度上证实了最初预测的减少。因此，这一现场测试可以作为“概念验证”，证明只要设计得当，刚性防波堤能够显著降低振动水平。(C) 2015 Elsevier Ltd.版权所有。
This paper discusses the design, the installation, and the experimental and numerical evaluation of the effectiveness of a stiff wave barrier in the soil as a mitigation measure for railway induced vibrations. A full scale in situ experiment has been conducted at a site in El Realengo (Spain), where a barrier consisting of overlapping jet grout columns has been installed along a railway track. This barrier is stiff compared to the soil and has a depth of 7.5 m, a width of 1 m, and a length of 55 m. Geophysical tests have been performed prior to the installation of the barrier for the determination of the dynamic soil characteristics. Extensive measurements have been carried out before and after installation of the barrier, including free field vibrations during train passages, transfer functions between the track and the free field, and the track receptance. Measurements have also been performed at a reference section adjacent to the test section in order to verify the effect of changing train, track and soil conditions over time. The in situ measurements show that the barrier is very effective: during train passages, a reduction of vibration levels by 5 dB is already obtained from 8 Hz upwards, while a peak reduction of about 12 dB is observed near 30 Hz immediately behind the barrier. The performance decreases further away from the jet grouting wall, but remains significant. The experimental results are also compared to numerical simulations based on a coupled finite element-boundary element methodology. A reasonable agreement between experiments and predictions is found, largely confirming the initially predicted reduction. This in situ test hence serves as a 'proof of concept', demonstrating that stiff wave barriers are capable of significantly reducing vibration levels, provided that they are properly designed. (C) 2015 Elsevier Ltd. All rights reserved.