TA 201-MmE PROJECT REPORT. Cantilever Bridge

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1 TA 201-MmE PROJECT REPORT Cantilever Bridge INSTRUCTOR: -Dr. J. Ramkumar TUTOR: - Prof. Kallol Mondal SECTION: - M1 / M2 GROUP NO. 9 Amit Kumar Y9073 Kumar Kislay Y9294 Mattam Pratap Naidu Y9327 Mohit Singh Y9343 Rohit Kumar Sinha Y9493

2 CONTENTS Acknowledgements General Description 1. Motivation 2. Innovations Procedure Processes Involved Cost Estimation Difficulties Faced Scope for Improvement

3 ACKNOWLEDGEMENTS We sincerely express our gratitude to our tutor Prof. Kallol Mondal, our MME laboratory in charge Mr. G.P.Bajpai sir, and all the other guides of the TA 201 MME lab for their valuable support and advice in making this project possible. Without their moral and technical support we would not have been able to complete this effortful task. Overall we thank our instructor-in-charge Dr. J. Ramkumar for providing us with the opportunity to make something creative along with gaining hands-on-laboratory experience. THANK YOU

4 GENERAL DESCRIPTION A Cantilever Bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end. Large cantilever bridges are designed to handle road or rail traffic using trusses built from structural steel. The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet. MOTIVATION The motivation for making this project was drawn from Newark Bay Bridge. The Newark Bay Bridge (officially named the Vincent R. Casciano Memorial Bridge) is steel through arch bridge connecting the cities of Newark and Bayonne in New Jersey, USA. It was completed on April 4, 1956 INNOVATIONS We did some slight modifications in the original model to complete the project effectively using the available lab facilities and in constrained time. Tapering of pillars to reduce weight of casting. Providing large base area to the pillars for their stability. Inclusion of a thicker sheet metal below the deck for its proper welding with the pillars. Deck is a rectangular box made by a thin sheet metal folding instead of a thick metal slab to reduce the weight.

5 PROCEDURE First of all casting of pillars was done using a thermocole pattern, introducing designs on it for aesthetic taste. Simultaneously deck was made by forming thin sheet metal into a box which was then locked by brazing. Then we moved on to shearing and bending of mild steel rods for making arches and trusses for the bridge. After that the system of arches and side trusses was given shape by welding and brazing, two parallel arch system were made independently. At the same time the cast pillars were ground to improve dimensional accuracy. The deck was fixed to a thicker sheet metal with the help of brazing, and then the pillars welded on the thick sheet. Subsequently the two arch systems were welded to the deck. Two cars, made by sheet metal shearing, folding and resistance welding were put on the deck to add life to the project. Then the two arch systems were connected via top trusses which were fabricated by brazing. Finally, finishing touch was given to the pillars and the arch systems by grinding with hand grinder. Oiling was also done to prevent rusting.

6 PROCESSES INVOLVED Casting: Casting was used for making pillars of the bridge. Since pillars are meant to bear the load of the whole structure, we preferred casting process. Welding and Brazing Process: Primarily we used following joining processes 1. Brazing: For making the truss system as the truss rods were very small in size and thus difficult to weld. 2. Gas Metal Arc Welding (GMAW): For joining pillars and arch systems to the deck as strong joints were required at these places. 3. Resistance Welding: For joining wheels made of GI sheets to the cars. Sheet Metal Forming: We used sheet metal work for making the deck and two cars. Metal Cutting: To separate the runner from the cast with the help of all-cut machine.

7 COST ESTIMATION ITEM RATE QUANTITY AMOUNT Thermocole Rs. 15 per sq feet 0.50 sq feet Rs. 7.50/- Fevicole Rs. 5/tube 1 tube Rs. 5/- Pig Iron Rs. 50/kg 4.5 kg Rs. 225/- Electricity used Rs. 4.80/unit 2 units Rs. 9.60/- Mild steel sheet (upto 3mm) Mild steel rods Rs. 40 per sq feet 0.28 sq feet Rs /- Rs. 30/kg 1.15 kg Rs /- Mild steel sheet (upto 1mm) GI sheet (upto 1mm) Rs. 16 per sq feet 0.62 sq feet Rs. 10/- Rs. 20 per sq feet 0.1 sq feet Rs. 2/- Unskilled Labour Rs. 25 per hr 13 X 5 hr Rs. 1625/- Skilled Labour Rs. 50 per hr 3 hr 150/- Total Rs. 2080/- Overhead charges: 10% = Rs. 208/Gross total = Rs. 2288/-

8 DIFFICULTIES FACED Deck was made of thin sheet metal box. So, welding of pillars to it was not possible. Solution: We placed the box on a thick sheet metal which could be welded with the pillars. Unexpected bending of thick sheet metal during its welding with the pillars, upsetting their levelling. Solution: We connected the bases of the adjacent pillars with square rods to provide proper levelling. The whole arch system was to be kept in a plane while brazing. Solution: We held the arch system with tong throughout the process. Due to insertion of thick sheet metal in the deck the dimension of pillars did not match with the arch system. Solution: We welded the arch system with the deck instead of pillars.

9 SCOPE FOR IMPROVEMENT. For better performance we could have used tata GI sheet which is not prone to rust easily.

Design for welding: Design recommendations

Design for welding: Design recommendations Arc welding can be used to weld almost any kind of assembly, including even complex structures. Arc weldments use a wide variety of ferrous and non ferrous metals.