Pravara Rural Education Society College of Architecture
Pravara Rural Education Society College of Architecture
Pravara Rural Education Society College of Architecture
REPORT ON
SEMESTER VII
INTRODUCTION
LONG SPAN STRUCTURE’S Structures with span larger than 15-20 meters are regarded to as Long Span
Structures. For Such structures span is unable to be achieved with ordinary R.C.C. construction.
Generally long spans result in flexible, column-free internal spaces, reduces substructure costs and time
to erect the structure.
Form - Active Systems of flexible, non-rigid matter, in which the redirection of forces is effected by
particular form design and characteristic form stabilization
Section - Active
Systems of rigid, solid, linear elements, in which redirection of forces is effected by mobilization of
sectional forces
Vector - Active
Systems of short, solid, straight lineal members, in which the redirection of forces is effected by vector
partition, i.e. by multidirectional splitting of single force simply to tension or compressive elements
Surface - Active Systems of flexible or rigid planes able to resist tension, compression or shear, in which
the redirection of forces is effected by mobilization of sectional forces
HOWRAH BRIDGE
• Howrah Bridge is a cantilever bridge with a suspended span over the Hooghly River in West
Bengal, India.
• Location : Howrah, Kolkata
• Architect : James Meadows Rendel
• Total length : 705 m
• Opened : February 3, 1943
• Construction started : 1935
• It weathers the storms of the Bay of Bengal region, carrying a daily traffic of approximately
100,000 vehicles and possibly more than 150,000 pedestrians
The following are some of the advantages of steel bridges that have contributed to their :
•They could carry heavier loads over longer spans with minimum dead weight, leading to smaller
foundations.
•Steel has the advantage where speed of construction is vital, as many elements can be prefabricated
and erected at site.
•In urban environment with traffic congestion and limited working space, steel bridges can be
constructed with minimum disruption to the community.
•Greater efficiency than concrete structures is invariably achieved in resisting seismic forces and blast
loading.
•Due to shallow construction depth, steel bridges offer slender appearance, which make them
aesthetically attractive. The reduced depth also contributes to the reduced cost of embankments.
•Semi through Type Bridge -The deck lies in between the top and the bottom of the main load carrying
members. The bracing of the top flange or top chord under compression is not done and part of the load
carrying system project above the floor level. The lateral restraint in the system is obtained usually by
the U-frame action of the verticals and cross beam acting together.
CLASSIFICATION BASED ON THE MAIN STRUCTURAL SYSTEM
Many different types of structural systems are used in bridges depending upon the span,carriageway
width and types of traffic. Classification, according to make up of main loadcarrying system, is as follows:
(i)Girder bridges -Flexure or bending between vertical supports is the main structural action in this type.
Girder bridges may be either solid web girders or truss girders or box girders. Plate girder bridges are
adopted for simply supported spans less than 50 m and box girders for continuous spans up to 250 m.
Truss bridges are suitable for the span range of 30 m to 375 m. Cantilever bridges have been built with
success with main spans of 300m to 550m.
(v)Suspension bridges -The bridge deck is suspended from cables stretched over the gap to be bridged,
anchored to the ground at two ends and passing over tall towers erected at or near the two edges of the
gap. Currently, the suspension bridge is best solution for long span bridges.
Arched bridge
CONSTRUCTION
•Between towers bridge deck hangs from panel points in the lower
chord of the main trusses with a series of hungers
FOUNDATION
The main tower is founded with single monoliths which are 55.31 x
24.8m in plan with 21 chambers
ARTICULATION JOINTS