OPTIMIZATION OF PRESTRESSED CONCRETE GIRDER

Bhawar P.D, Wakchaure M.R, Nagare P.N

Abstract: Bridge construction today has achieved a worldwide level of importance. Bridges are the key elements in any road network Use of prestressed concrete I girder bridge is gaining popularity in bridge engineering fraternity because of its better stability, serviceability, economy, aesthetic appearance and structural efficiency. This paper concerned idea about prestressed concrete.In the method of prestressing two types are consider that pre tensioning and post tensioning .At the time of prestressing different losses are consider. These are the losses due to elastic shortening, friction losses, relaxation losses, losses due to creep and shrinkage. In this way total amount of losses in pretensioning and post tensioning calculate and detailed information has given in this report. The objective is to minimize the total cost in the design process of the bridge system considering the cost of materials like steel, concrete, tendons etc. For a particular problem the design variables considered for the cost minimization of the bridge system, are depth of girder, various cross sectional dimensions of the girder, number of tendons, A programme is developed for analysis and designing an low cost prestressed girder in MATLAB R2010a software. The optimtool is used to find out minimum cost of structure Illustrative case of prestressed girder presented and discuss by using active set method from optimtool. Optimization problem is characterized by considering design variables and bound constraints are according to AASHTOO Standards ,IRC 21- 2000 bridge specifications .The proposed cost optimization approach is compared with an existing project which leads to a considerable cost saving while resulting in feasible design.

Keywords: Post tension I girder, Conventional design, Optimal design, MATLAB Software etc…

DOI: https://doi.org/10.15623/ijret.2015.0403105