Parametric optimization for 3D concrete printingin backfill arch bridge construction

Abstract

3D Concrete Printing (3DCP) is an emerging construction technology that enables the fabrication of complex structural forms while improving construction efficiency. However, the structural design of backfilled 3DCP arch bridges remains insufficiently understood, particularly regarding the influence of geometric parameters and printed material properties. This research presents an integrated framework for the parametric design, multi-objective optimization, numerical analysis, and experimental validation of 3DCP arch bridges. A finite element model was developed in Karamba3D using experimentally determined material properties and validated through lab-scale testing. Parametric analysis and multi-objective optimization using the Octopus evolutionary solver were performed to investigate the effects of rise height, span length, thickness, and leg height on structural performance. The results identified the rise-to-span ratio as the governing design parameter, with optimum values ranging from 0.30 to 0.38. A full-scale arch bridge was subsequently fabricated and tested under realistic backfill conditions, achieving an ultimate load capacity of 200 kN with good agreement between experimental and numerical results. The proposed framework provides a validated methodology for the design and optimization of 3DCP arch bridges and supports the future application of additive manufacturing in sustainable bridge engineering.