Assessment of Design Codes and Design of Bridge Using British Standard (BS5400) and American (AASHTO-LRFD) Code

Abstract

Abstract : This study presents a comprehensive comparative analysis of two major bridge design codes: the American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO-LRFD) and the British Standard (BS5400). It aims to critically examine the methodologies, technical specifications, and overall effectiveness of these codes in ensuring the structural integrity, durability, and efficiency of bridge designs. By comparing these standards, the research seeks to highlight their respective strengths and limitations, thereby offering valuable insights for potential advancements in bridge engineering practices. After setting the stage with a thorough introduction and a review of relevant literature, the research delves into an in-depth examination of the design procedures advocated by the AASHTO-LRFD and BS5400 codes. It scrutinizes the foundational principles underpinning each code and their practical application in the design of bridge structures. Chapter 4 stands out by presenting an empirical analysis conducted through advanced engineering software CSiBridge 24. This segment of the study unveils notable differences between the codes in terms of structural component forces and moments. Specifically, the axial load results show that for an abutment column, AASHTO-LRFD prescribes 2747.877 kN, while BS5400 suggests a more conservative value of 3499 kN. Similarly, for a pier column, AASHTO-LRFD's calculation of 4048.873 kN contrasts with BS5400's 4843 kN. Additionally, the moment calculations for girders reveal that the interior girder moment according to AASHTO-LRFD is 2898 kN.m, with the exterior at 2464 kN.m, where in BS5400 specifies 2759 kN.m for the interior and a significantly higher 3939.64 kN.m for the exterior girder. These findings underscore a conservative trend in the BS5400 code, manifesting in higher force and moment values that suggest a design approach geared towards enhanced robustness and stiffness in bridge structures. The results also indicate potential areas for optimization in each code. The concluding chapter synthesizes these insights, drawing comprehensive conclusions and formulating recommendations for further research and development in bridge design standards. This study contributes to the ongoing discourse on bridge engineering, aiming to influence future code improvements and foster the advancement of bridge design methodologies.