Abstract The use of prefabricated vertical drains (PVDs) to improve soft soil has received much attention in the recent past, however, there is still a lack of rigorous analytical solutions that can incorporate the time- and depth-dependent behaviour of drains into the consolidation of multi-layered soil. This study thus presents a novel approach where the spectral method is used to capture the degradation in discharge capacity of drains over time and depth, while the average consolidation of different soil layers with regard to vertical and radial drainage is computed. In this approach, the excess pore water pressure profile across different soil layers is described as a single expression using matrix operations. This proposed method is then verified with laboratory and field investigations where the degradation of PVDs is captured and compared with other solutions. The results show that this method can predict the soil behaviour with greater accuracy and flexibility whereas there is a significant deviation in the predicted consolidation when the degradation of drains is not considered properly. A parametric investigation is also carried out using the proposed solution to further highlight its ability to evaluate the effect that drain degradation can have on the consolidation of multi-layered soil.

中文翻译：

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基于谱法的结合排水退化的垂直和径向固结分析

摘要 近年来，使用预制垂直排水管 (PVD) 改善软土受到了广泛关注，然而，仍然缺乏严格的分析解决方案，可以将排水管的时间和深度相关行为纳入固结中。多层土壤。因此，本研究提出了一种新方法，其中使用频谱方法来捕捉排水渠排水能力随时间和深度的退化，同时计算不同土壤层在垂直和径向排水方面的平均固结度。在这种方法中，跨不同土层的超孔隙水压力剖面被描述为使用矩阵运算的单一表达式。然后通过实验室和现场调查验证了该建议的方法，其中捕获了 PVD ​​的降解并与其他解决方案进行了比较。结果表明，该方法可以更准确、更灵活地预测土体行为，而当没有正确考虑排水管退化时，预测的固结存在显着偏差。还使用所提出的解决方案进行了参数调查，以进一步强调其评估排水退化对多层土壤固结的影响的能力。