Abstract In practice, horizontal drains are often arranged at certain depth in dredged clays to accelerate the consolidation process in layered clay-sand reclamation subjected to surcharge preloading, and the layout of horizontal drain is usually determined based on a trial-and-error procedure. Based on the transfer matrix approach, a semi-analytical solution is derived using Laplace transform and its numerical inverse methods for use to optimize the design of horizontal drain in layered clay-sand reclamation. The effectiveness of the proposed technique is demonstrated by comparing against other analytical solutions. The sensitivity of the optimal position of horizontal drain to the anisotropic coefficient of consolidation, the thickness ratio, and the anisotropic permeability is discussed. Results show that the optimal position of horizontal drain is related to the drainage capacity in adjacent soil layers, and it always moves towards the boundary with a lower drainage capacity. In the end, an example of a four-layered soil is calculated to demonstrate the advantage of conducting the optimal design of horizontal drain. Remarkably, the rate of consolidation with the optimal implementation of horizontal drain is faster than the conventional design with horizontal drain at the mid-height.

中文翻译：

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复垦夹层粘土排水系统水平排水管定位设计

摘要 在实际中，水平排水管通常在疏浚粘土中设置一定深度，以加速分层粘土砂复垦中的超载预压固结过程，水平排水管的布置通常通过反复试验确定。基于传递矩阵方法，利用拉普拉斯变换及其数值逆方法推导出半解析解，用于优化分层粘土砂复垦水平排水沟的设计。通过与其他分析解决方案进行比较，证明了所提出技术的有效性。讨论了水平排水沟的最佳位置对固结各向异性系数、厚度比和各向异性渗透率的敏感性。结果表明，水平排水管的最佳位置与相邻土层的排水能力有关，并且总是向排水能力较低的边界移动。最后以四层土为例，论证了进行水平排水优化设计的优势。值得注意的是，水平排水沟优化实施的固结速度比中间高度水平排水沟的传统设计更快。