Abstract

This study aims to examine the effects of surrounding soil layers and furthermore lens properties on induced vibrations by underground railway twin tunnels and comparing with the single tunnel. First, the predicted models for the vibration of the underground tunnel(s) are verified against in situ measurements. The tunnel(s) are assumed to be located in two-layer soil, and the influence of upper soil layer thickness, elastic modulus, and soil layers’ inclination angle (for three values of 5, 10, and 15 degrees) on surface vibrations are investigated. Furthermore, the influence of the presence of soft and stiff soil lens with various thicknesses in several levels respect to the tunnel(s) and the effect of the inclination angle of the soil lens (for two values of 5 and 15 degrees) on the surface vibrations is examined. The results indicate that the layered region around the single and twin tunnels increases the vibrations level up to 10 dB respect to the uniform soil layer. Also, the effect of soil lens with larger thickness is remarkable. The maximum inclination angle of 15 degrees for soil layers and soil lens respectively cause in 9 and 5 dB increase in the surface vibrations level.

摘要

本研究旨在通过地下铁路双隧道检查周围土层以及透镜特性对诱发振动的影响，并与单隧道进行比较。首先，根据现场测量验证地下隧道振动的预测模型。假设隧道位于两层土中，上层土层厚度、弹性模量和土层倾角（5、10和15度三个值）对地表振动的影响被调查。此外，不同厚度的软硬土透镜的存在对隧道的影响以及土透镜的倾斜角（5度和15度这两个值）对地表的影响检查振动。结果表明，单隧道和双隧道周围的分层区域相对于均匀土层将振动水平提高了 10 dB。此外，较大厚度的土壤透镜效果显着。土壤层和土壤透镜的最大倾角为 15 度，分别导致表面振动水平增加 9 分贝和 5 分贝。