Abstract In this paper, the effect of different thicknesses of Deconstructed Tires Under Sleeper Pads (DT-USP) and different Unconfined Compressive Strength (UCS) values of mother rocks of ballast aggregates were studied in the degradation of railway ballast. For this purpose, in the first step, both static and dynamic bedding modulus of DT-USP's were extracted in the laboratory according to DIN standard requirements. In continuation, the physical and mechanical properties of the three different ballast types taken from Shahriar, Anjilavand, and Kouhin quarries in Iran were obtained via a series of standard lab tests. The UCS of core specimens taken from the mother rocks of the mentioned queries were ranked as low (159 MPa), medium (216 MPA), and high (285 MPa) respectively. Finally, 36 ballast box test experiments with and without the presence of DT-USPs in three thicknesses of 7, 11, and 13 mm were carried out and their results were compared up to 200,000 loading cycles to investigate the cyclic behavior of ballast samples. Experiment results were elicited in the form of settlement, Hardin breakage index (Br), ballast stiffness, and ballast Damping Ratio (DR). The results demonstrate for ballast of Shahriar quarry by increasing of the DT-USP's thickness from 7 to 13 mm, settlement, Br, and stiffness have decreased by 38.4%, 6.9%, and 80.5% respectively and DR has increased by 199.2% while these reported percentages, i.e. settlement, Br, and Stiffness have decreased and DR has increased after strengthening the ballast mother rock in the cases of Anjilavand and Kouhin quarries. On the other side, based on the achieved results for all three categories of ballast strengths, the DT-USP with 11 mm thickness has shown the most suitable performance.

中文翻译：

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循环荷载下枕垫下解构轮胎对铁路道碴退化的影响

摘要 本文研究了不同厚度的枕垫下解构轮胎（DT-USP）和不同的道碴骨料母岩无侧限抗压强度（UCS）值对铁路道碴降解的影响。为此，第一步，根据 DIN 标准要求在实验室中提取 DT-USP 的静态和动态层理模量。接着，通过一系列标准实验室测试获得了取自伊朗 Shahriar、Anjilavand 和 Kouhin 采石场的三种不同类型镇流器的物理和机械性能。取自上述查询的母岩的岩心标本的 UCS 分别被列为低 (159 MPa)、中 (216 MPA) 和高 (285 MPa)。最后，在 7、11 和 13 毫米三种厚度下进行了 36 次有和没有 DT-USP 的镇流器箱测试实验，并将它们的结果进行了最多 200,000 次加载循环的比较，以研究镇流器样品的循环行为。实验结果以沉降、哈丁破损指数 (Br)、道碴刚度和道碴阻尼比 (DR) 的形式得出。结果表明，通过将 DT-USP 的厚度从 7 毫米增加到 13 毫米，Shahriar 采石场的压载物，沉降、Br 和刚度分别降低了 38.4%、6.9% 和 80.5%，DR 增加了 199.2%，而这些在 Anjilavand 和 Kouhin 采石场加固压载母岩后，报告的百分比，即沉降、Br 和刚度降低而 DR 增加。另一方面，