Three-Dimensional Simulations of Plate Anchor Pullout in Granular Materials

Abstract

Plate anchors are embedded into the ocean floor to provide holding capacity for offshore structures. Anchor holding capacity is a function of both the anchor and soil properties. Although plate anchors have been widely studied experimentally and numerically, there is still no universally agreed-upon design approach, indicating that the problem physics remain elusive. In this work, discrete-element method (DEM) simulations were used to investigate the behavior of plate anchors during pullout in an effort to elucidate some of the microscale physical processes that influence overall system behavior. Macroscale assembly response was compared to published experimental results and empirical solutions. The influence of embedment ratio, anchor roughness, soil density, and anchor size on holding capacity was investigated, and system-scale results reasonably agreed with previously published work. Thus, observations of the simulated contact force network and particle velocity during uplift were used to provide insight into anchor failure mechanisms. Finally, the model was used to briefly explore the response of a cyclically loaded plate anchor embedded in a granular assembly.

Simulation of compound anchor intrusion in dry sand by a hybrid FEM+SPH method

“…Each particle is subjected to gravitational acceleration as well as elastic contact forces and dissipative normal and frictional forces from adjacent interacting particles. Many authors used the DEM to analyze cone penetration (e.g., (Calvetti and Nova, 2005;Butlanska et al, 2014;Gens et al, 2018;Khosravi et al, 2019)) and anchor pull-out (e.g., (Evans and Zhang, 2019;Liang et al, 2021)) but the DEM is computationally intensive. In many engineering scenarios, representing each soil grain by a particulate element is not feasible, and that is why a scaling factor is often used to allow simulation of large volumes of soil with a smaller number of large particulate elements (Gens et al, 2018;Evans and Zhang, 2019).…”

Three‐dimensional upper‐bound limit analysis of ultimate pullout capacity of anchor plates using variation method

“…Korkmaz et al 24 used PLAXIS, a numerical analysis software, with the Mohr-Coulomb and hardening-soil constitutive model to obtain the ultimate pullout capacity of a circular anchor in loose and dense sands, and the results for shallow buried depths were in good agreement with existing theoretical results, but at deep-buried depths, the theoretical results were higher. Choudhary et al 25,26 investigated the uplift characteristics of horizontal and vertical anchor plates in sand through a three-dimensional finite difference method and model tests, and analyzed the effects of the embedment ratio, internal friction angle of the soil, anchor size, and roughness. Evans et al 27 applied the discrete element method to analyze the uplift behavior of a horizontal anchor plate and the response of the anchor plate under cyclic loading, and the effects of the embedment ratio, roughness, size, and soil properties on the uplift capacity were analyzed.…”

Influência da largura da base na resistência ao arrancamento de ancoragem em formato L assentada em solo areno-argiloso

“…Nos últimos anos foram desenvolvidas várias pesquisas para estimar a capacidade de ancoragens no solo (Zhang & Evans, 2019;Hu et al, 2021;Liang et al, 2021) mas, apesar disso, muitos modelos utilizados ainda possuem uma grande parcela de empirismo, principalmente nos casos do efeito combinado de esforços verticais e horizontais.…”