A COMPARISON OF BRIDGE ASSESSMENT USING MANUAL METHOD OF PLASTIC ANALYSIS AND COMPUTER APPROACH

ABSTRACT

This project demonstrated how the theory of plastic analysis was used in the assessment of highway bridge with the aim of comparing the manual method of calculating for plastic to that of a computer approach, analysing the moving load of vehicle and the moment caused at each point of the bridge and how they are deformed. The application of manual techniques, which necessitates the use of collapse mechanisms also referred to as Kinematic method of plastic analysis. In the software approach, the load was placed at different distance on the structure and also the reaction of the structure to that applied load thereby assessing the plastic moment caused by the collapse load derived from the manual method. The software used for this model is the STAAD PRO software. This was used in analysing the critical beam of the bridge carryinG the most loads according to the Euro code EN 1991-2:2003. The STAAD PRO software was intentionally selected cause of the familiarity of the software to the civil engineering field and the versatility of the software. The results derived showed the deformation of the beam when several loads are applied at different positions on the beam. Also, the difference between both approaches were minimal as it shows the similarity of both results when conditions of the structure are uniform. From the selected section of the steel girder, the collapse load of 783.34KN was gotten from the plastic moment of 6658.34KNm which was slightly different from the results from the software having a value of 6.6×103KNm.