Efficiency of in-filled (geofoam) trenches in mitigating train-induced vibrations: A case study of Tehran-Tabriz railway

Ground-borne vibrations resulting from the railway and road traffic have an adverse impact on the environment and nearby infrastructures. The focus of this study is on a specific part of the Tehran-Tabriz Railway located in the vicinity of Fath Highway, Tehran. In the investigated area, there are many residential buildings very close to the railway, and consequently, the train-induced vibrations make the people disturbed. After determining the soil layering and their properties using site investigation, the effect of geofoam trenches in mitigating train-induced vibrations was numerically investigated. The results showed that both the trench depth and width were important, especially at higher train speeds. Furthermore, the trenches installed further from the track performed better than the ones installed closer. In addition, the vibration levels before and after trench installation for different cross-sectional areas and slenderness ratios of the trench were numerically determined. The analyses are associated with the freight train speeds ranging from 40 km/hr to 160 km/hr. Also, the effect of several infill materials was investigated, and it was shown that softer infill materials perform better than harder ones. Finally, a procedure to adjust the results for different train types was proposed. Several graphs for design of geofoam trenches were proposed in this study.

Automated summary

This study focused on the vibration issues caused by trains along the Tehran-Tabriz Railway, investigating the properties of soil layers and geofoam trenches through site investigation and numerical analysis. It was found that trench depth and width are crucial in mitigating vibrations, especially at higher train speeds, with trenches located further from the track performing better. Additionally, softer infill materials were shown to be more effective than harder ones in reducing vibrations.