The identification of soil heaves inside a caisson during installation is important for the caisson’s design length, since the inner soil heave during the caisson installation affects the final effective caisson penetration depth, hence caisson capacity. This paper reports an extensive parametric study of stiffened caissons penetrating in double-layer of soft-over-stiff clay using large deformation finite element (LDFE) analyses. The LDFE analysis was first validated against the existing results from centrifuge tests and numerical analyses. Then the parametric study was carried out to explore the inner soil movements during stiffened caisson installations with various influencing factors, such as caisson diameter, caisson stiffener width, top-layer soil strength, double-layer soil strength ratio, and roughness of soil-caisson interface. It is found that the caisson diameter, stiffener width, and top-layer soil strength have significant influences on the inner soil behaviors. Besides, the movements of both soil surface and soil layer interface were also investigated. Based on the LDFE results, design formulas are proposed to estimate the inner soil heaves for soft-over-stiff clay. A design formula to estimate the movement of the soil layer interface for soft-over-stiff clays is also reported.

在安装过程中识别沉箱内部的土隆对沉箱的设计长度很重要，因为在沉箱安装期间内部土隆会影响最终的有效沉箱穿透深度，从而影响沉箱容量。本文报告了使用大变形有限元 (LDFE) 分析对穿透双层软过硬粘土的加筋沉箱进行的广泛参数研究。LDFE 分析首先根据离心机测试和数值分析的现有结果进行验证。然后通过参数研究探讨了加筋沉箱安装过程中内部土体运动的影响因素，如沉箱直径、沉箱加劲肋宽度、顶层土强度、双层土强度比和土沉箱粗糙度。界面。结果表明，沉箱直径、加劲肋宽度和顶层土强度对内部土的行为有显着影响。此外，还研究了土壤表面和土层界面的运动。根据 LDFE 结果，提出了设计公式来估计软过硬粘土的内部土壤隆起。还报告了一个设计公式，用于估计软硬粘土的土层界面的运动。