Analytical Study Of Load Rating On RCC Box Girder Superstructure Under The Effect Of IRC Loadings

Abstract

It is observed that over the course of time structural components weakens and their ability to carry the self weight along with the superimposed load decreases. Consequently, it becomes very much important and vital to periodically assess the strength, stability and the performance of the bridge and other structure in order to ascertain their remaining residual strength and to ensure safety. There are different experimental methods available which uses the concept of Non-Destructive testing in order to ascertain the performance and the condition of any structure at any point of time. There are numerous experimental method which are used to perform the Load Rating Analysis but there is no provision to perform the same rating analysis analytically as per the Indian code on bridge related software. This paper generally deals with providing an analytical solution which can be used in order to estimate the residual strength of the bridge structure and perform the Load Rating Analysis analytically on Midas Civil Software. The study basically involves the modelling and Analysis of 2 Reinforced Concrete Box Girder Superstructure, each of span length 40m situated in Lucknow analyzed as per the Indian Standard Codes. Both of the bridge model represents the condition of the bridge structure at a specific time period. The time gap between the analysis of the two models is assumed to be 70 years. The bridge model is modelled and analyzed with the help of Midas Civil Software and the Load carrying capacity of the structure is evaluated based on the different statistical parameters such as Vertical Displacement, Shear Force and Bending Moment. At last a comparative study is conducted between the two models. The analysis revealed that the Bridges Lose their load bearing capacity and strength after a time period of 70 years. A considerable increase in the value of vertical displacement and bending moment was observed beyond the safe and permissible limit of the structure. The analytical approach demonstrated in this study can be applied to various bridge structure such as RCC and PSC Tee Beam Bridge, I Girder bridge, cable stayed bridge etc.