Numerical construction tests to assess the feasibility of placement grids for Cubipod Homogeneous Low-Crested Structures

Abstract

Placement grid design is a key phase when constructing armor layers in mound breakwaters. Homogeneous Low-Crested Structures (HLCS) are low-crested structures designed as artificial reefs for marine colonization, coral reef regeneration and beach protection. The placement grid affects the construction feasibility, hydraulic stability and wave transmission of HLCS. This study presents a numerical methodology to simulate a realistic placement procedure for armor units during the construction of HLCS. This numerical simulator is based on the open-source physics engine Bullet Physics Engine (BPE), which applies Newton's laws of motion to rigid bodies. From an initial theorical placement grid for Cubipod HLCS, a series of numerical realistic unit placement tests are carried out to emulate the placement process at prototype scale; placement velocity and spatial deviation of crawler cranes are given parameters associated with each specific project. Considering the placement velocity and spatial deviation during construction, the quality of each specific placement grid is associated with the measured placement errors and the corresponding initial construction deviation to HLCS. This numerical methodology is valuable to understand the influence and the uncertaintly of the construction procedure of armor layers in mound breakwaters.