Abstract Recent advances in tire recycling technologies coupled with increasing global environmental awareness have resulted in several new products derived from scrap tires, including tire-derived aggregate (TDA). TDA is an inexpensive engineered lightweight backfill material with excellent geotechnical properties, produced by shredding scrap tires into sizes ranging from 12 mm to 305 mm. This paper examines the performance of rigid footings resting on a surface of conventional backfill materials overlying a TDA layer. The study includes three full-scale field tests with TDA layers of different thicknesses. Based on the field tests, rigorous 3D finite element analyses (FEA) were developed to study the failure mechanism of shallow foundations over TDA. In addition, the effect on the footing performance of changing critical parameters including the TDA layer thickness, the strength of the top granular backfill, the foundation depth, the footing width, the footing shape, and subsurface soil conditions was studied. It was found that in comparison to using only conventional granular backfill, using an underlying TDA layer for shallow foundations results in a significant improvement in transferring the stresses and reducing the stress influence zone underneath the footings. For instance, before the punching shear failure in the top layer occurred, TDA was able to reduce the transferred stresses by almost one half of that by the natural backfill. Furthermore, the results of the parametric study illustrated the dependency of the bearing capacity of the spread footing on the relative thicknesses of the TDA and the top granular layers, in addition to the foundation width.

中文翻译：

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轻质 TDA 回填的浅层基础：现场测试和 3D 数值建模

摘要 轮胎回收技术的最新进展以及全球环保意识的提高导致了几种从废轮胎中提取的新产品，包括轮胎衍生骨料 (TDA)。TDA 是一种廉价的工程轻质回填材料，具有出色的岩土特性，通过将废轮胎粉碎成 12 毫米到 305 毫米的尺寸而生产。本文研究了位于 TDA 层上的传统回填材料表面上的刚性基脚的性能。该研究包括使用不同厚度的 TDA 层进行的三个全尺寸现场测试。基于现场测试，开发了严格的 3D 有限元分析 (FEA)，以研究 TDA 上浅基础的破坏机制。此外，研究了改变关键参数对基础性能的影响，包括 TDA 层厚度、顶部颗粒回填的强度、基础深度、基础宽度、基础形状和地下土壤条件。结果表明，与仅使用传统的颗粒回填相比，在浅地基中使用底层 TDA 层可显着改善应力传递并减少地基下方的应力影响区。例如，在顶层发生冲切剪切破坏之前，TDA 能够将传递的应力降低几乎是自然回填的一半。此外，