PSI - Issue 70

Ashutosh Kumar et al. / Procedia Structural Integrity 70 (2025) 175–182

176

1. Introduction Anchors are foundational structures designed primarily to resist uplift (tensile) stresses. The history of anchors spans thousands of years, as they have been essential tools for maritime navigation, mooring vessels, and securing structures. Different types of anchors are used extensively in offshore and onshore construction, depending on the magnitude and type of loading, structure and subsoil conditions. A comprehensive description of different types of anchors and their field applications is reported by Das and Shukla (2013). Plate anchors are among the most common types used in civil engineering construction, offering an economical alternative to gravity and other embedded anchors for resisting uplift forces in both a marine and a terrestrial environment. These anchors typically supports transmission towers, submerged pipelines, moorings and cables anchored to the sea bed. Numerous studies have investigated the behavior of horizontal plate anchors embedded in a single layered cohesionless soil (Balla, 1961; Rowe and Davis, 1982; Tagaya and Tanaka, 1983; Ilamparuthi and Muthukrisnaiah, 1999; Ilamparuthi et al., 2002; Merifield et al., 2006; Merifield and Sloan, 2006; Ilamparuthi and Shreni, 2009; Bildik and Laman, 2011; Rokonuzzaman and Sakai, 2012; Choudhary and Dash, 2013; Choudhary et al., 2019; Kumar et al., 2023). However, to address the complexities of natural soil conditions, accurately predict uplift capacity, and optimize anchor design for safety and cost-efficiency, it is of utmost important to understand the behaviour of plate anchor in layered soil. Limited literature is available on the behaviour of plate anchor in layered soil (Stewart, 1985; Bouazza and Finlay, 1990; Kumar, 2003; Sakai and Tanaka, 2007; Sahoo and Ganesh, 2018; Lee and Park, 2021). However, these studies focus on circular, rectangular, and strip anchor. As per the literature available, no studies have investigated on square anchor plates embedded in two-layered soil. Therefore, understanding the uplift behavior of horizontal square anchor plate in layered soil with varying properties is essential. Hence, this study aims to evaluate the uplift performance of square plate anchors placed in two-layered sand with different soil characteristics using a series of numerical models with H/B of 1, 2, and 3, with the aid of 3-D finite element modeling. Nomenclature A Area of the plate anchor B Width of the plate anchor plate H Embedment depth of an anchor plate H/B Embedment ratio F q Uplift capacity factor Q p Peak upliftstress h 1 Thickness of layer1 h 2 Thickness of layer2 ϒ 1 Unit weight of soil for layer 1 ϒ 2 Unit weight of soil for layer 2 ϕ 1 Internal friction angle of soil for layer 1 ϕ 2 Internal friction angle of soil for layer 2 ψ Dilation angle RD Relative density ϒ d max Maximum dry unit weight ϒ d min Minimum dry unit weight 3D 3 Dimensional FEM Finite Element Model NTS Not to scale 2. Numerical Investigation Numerical analysis is a powerful mathematical approach that effectively addresses intricate engineering challenges. The FEM, a widely recognized technique, is commonly used in civil engineering for both research and practical problem-solving. PLAXIS-3D, a computer program that performs finite element analysis to examine the stability and deformation of geotechnical engineering structures (PLAXIS 2019). To study the behavior of a horizontal square anchor plate, a finite element model was developed using FEM software. To eliminate the boundary effects, a large