Abstract
Corrugated Steel Structure (CSS) represents an alternative structural system that offers distinct advantages in terms of construction speed and material efficiency. This study aims to analyze the structural performance of long-span Aramco CSP bridges, specifically with 40-meter and 50-meter spans, using the Finite Element Method (FEM). The analysis refers to applicable bridge standards, while parameters not yet regulated in the Indonesian National Standard (SNI) are determined based on scientific references, international standards, and prior research. The analytical results indicate that the 40-meter span Aramco CSP bridge featuring a 13 mm Corrugated Steel Plate (CSP) with SS400 material grade experiences a maximum deflection of 12.438 mm, which is well below the allowable deflection limit of 50 mm. Meanwhile, the 50-meter span bridge with a 15 mm CSP thickness and SS490 material grade exhibits a maximum deflection of 22.350 mm, also below the allowable limit of 62.5 mm. From a mechanical perspective, this demonstrates that the arch configuration allows loads to be transferred via axial compressive forces toward the supports, thereby reducing bending moments within the structural elements. Consequently, this mechanism minimizes deflection and yields a more efficient internal force distribution. Equivalent stress analysis (Von Mises) reveals that the 40-meter span bridge generates a maximum stress of 310.33 MPa, which exceeds the material's yield strength of 250 MPa. In contrast, the 50-meter span bridge produces a maximum stress of 283.76 MPa, which remains below the material's yield strength of 285 MPa. Therefore, the 40-meter span Aramco CSP bridge requires structural reinforcement by either increasing the plate thickness or upgrading the material grade to fulfill the structural design criteria. The loads acting on the arch structure are propagated via axial compressive forces along the geometry toward both supports, effectively reducing bending stresses and resulting in minor deflections.