Hydraulic assisted bridges

working of hydraulic assisted bridges. various types of movable bridges. hydraulic unit for movable bridges. rolling bridge

1. Hydraulic Assisted Bridge Ishan Kossambe 13MCD0038

2. Introduction I ncorporates an integrated hydraulic system into the bridge in order to carry more weight Suitable for arch based bridges

3. How it works F orces in a lateral/horizontal direction at the supports T hree hinged arch L oading will cause the arch to spread

4. Supports L oad causes the three hinged arch to spread out P iston is held in place via a pined connection O -rings of the piston

5. Mid-Span of Bridge The high pressure hydraulic fluid causes another piston to become raised Counteracting the load   Calibration and calculation is required by changing the diameter of the piston and shafts

6. Advantages Little maintenance Quantity of material required to construct the bridge is reduced Increase its aesthetic and social impact Reversal of h ydraulic fluid s till r esults in e quilibrium

7. Disadvantages V ertical hydraulic column being required to be located in the center of the arch Vertical column type hydraulic bridges may never be used in arch bridges required to span gaps which are very high in the context of the altitude of the locale . Failure by very high force

8.  Overcoming the Disadvantages E liminating the single vertical hydraulic column Replacing hydraulic components placed at an angle A dding several, thicker O-rings and gaskets 

9. Potential Applications Pedestrian Footbridges Water Transportation Vehicular Transportation Light Vehicles Freight Vehicles Railway Transportation

10. Moving Bridges Drawbridge Bascule bridge Curling bridge Vertical-lift bridge Retractable bridge Tilt bridge

11. H ydraulic S ystems f or M ovable B ridges Objectives A bility to handle varying loads S mooth acceleration and deceleration P ositive locking in any position

12. Hydraulic Cylinders Two per span Tie rod and welded I ntermediate trunnion and spherical bearing clevis both ends T he national fluid power association (NFPA) established a standard for tie rod type hydraulic cylinders Tie rods should be inspected for corrosion damage

13. C ounterbalance V alves V arying loads, wind makes it unbalanced and causes run away A counterbalance valve keeps this condition in check Holding the bridge firmly in any position Acts as a check valve

14. Proportional Valves Smooth acceleration and deceleration G radually increasing or decreasing the amount of flow to the cylinders T he use of servo valves for th i s task is not recommended 0 - 9 volts dc/800 milliamps

15. Hydraulic Pump V ariable volume-bent axis-piston type pump S trong suction capability and greater dirt tolerance, make them a good choice for movable bridge P umps which require a boost or supercharge only add complexity to the design Horsepower limiter

16. Hydraulic Fluids ISO Grade Viscosity Normal Operating Temperature AW32 Light 1O -150°F AW46 Medium 3O -160°F AW68 Heavy 4O -170°F

17. Care to be Taken While Designing P umps and motors should be accessible for work V ibration mounts and hoses to isolate pump VIBRATION T he use of ANSI standard bolt pattern sub plate mounted valves Drilled manifolds to minimize piping and fittings Filters which are easy to change with good clogging indicators S traight thread "o” ring ports and fittings Large access covers for reservoirs

18. The Rolling Bridge C ompleted in 2004 as part of the  Grand Union Canal  office & retail development project at Paddington Basin, London . Despite the connotation of its name, it is more accurately described as  "curling " . D esigned by SKM Anthony Hunt with Packman Lucas, and built by Littlehampton Welding Ltd . The Hydraulic design and development was done by Primary Fluid Power Ltd in the North West . In 2005, the bridge won the British Structural Steel Design Award.

19. References http://en.wikipedia.org / http:// www.designingbuildings.co.uk/wiki/Hydraulic_Assisted_Bridges www.youtube.com H ydraulic systems for movable bridges by Michael A. Henley