Introduction

In railway tracks, transition zones are located between the civil structures and the embankments. In this sense, differential settlements take place due to the difference of stiffness between the two, resulting in direct damage to the track. Currently, railway managers have tried, without success, to solve this problem using granular wedges.

Purpose

For this reason, to achieve a continuous and gradual track vertical stiffness in transition zones, a new type of transition wedge has been designed using prefabricated concrete slabs. In addition, it was studied if the new wedge was valid to be installed in urban environments, as it is thought that the transmission of railway vibrations through concrete could be very high.

Method

With this purpose, firstly the design and validation of the new transition wedge has been carried out. To do this, the different alternatives were installed in a test field and the one with the best performance was selected. Once selected, an FEM was used to validate its performance compared to a granular wedge. Secondly, using the FEM of the validated solution, a comparison of the vibrational response of both alternatives was carried out to determine whether the new wedge is suitable for installation in urban environments.

Results and conclusions

The results showed that the new wedge using concrete slabs was an optimal solution to be installed in railway transition zones. However, these wedges did not show an adequate performance in urban environments, so the use of granular wedges was concluded to be more appropriate.

中文翻译：

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铁路过渡带预制楔在不同情况下的结构和振动性能

介绍

在铁路轨道中，过渡区位于土木结构和路堤之间。从这个意义上说，由于两者之间的刚度不同，会产生不同的沉降，从而直接损坏轨道。当前，铁路管理者已经尝试使用颗粒楔来解决该问题，但是没有成功。

目的

由于这个原因，为了在过渡区域中获得连续且逐渐变化的轨道垂直刚度，已经使用预制混凝土板设计了新型过渡楔。此外，还研究了新楔块是否可以有效地安装在城市环境中，因为人们认为铁路振动通过混凝土的传递可能非常高。

方法

为此，首先进行了新过渡楔的设计和验证。为此，在测试现场安装了不同的替代方案，并选择了性能最佳的替代方案。选择后，与颗粒楔形相比，使用有限元法来验证其性能。其次，使用经过验证的解决方案的有限元方法，对这两种方案的振动响应进行了比较，以确定新的楔块是否适合在城市环境中安装。

结果与结论

结果表明，使用混凝土板的新型楔形是在铁路过渡带安装的最佳解决方案。然而，这些楔形物在城市环境中没有表现出足够的性能，因此得出结论认为使用颗粒状楔形物更为合适。