This document provides an introduction to steel structures. It defines steel structures as structures made from organized combinations of structural steel members designed to carry loads and provide rigidity. Some key points covered include: the composition of steel as an alloy of iron and carbon; the main elements in a steel structure like beams, cables, and sections; advantages of steel such as high strength and ductility; and common uses of steel in construction like buildings, bridges, and industrial sheds. The document also provides details on the construction of the iconic Howrah Bridge in India.

1. INTRODUCTION TO STEEL
SUBMITTED BY:
ANAMIKA PATIL

2. STEEL STRUCTURES:
 WHAT ARE STEEL STRUCTURES ?
 A STRUCTURE WHICH IS MADE FROM ORGANIZED COMBINATION OF
STRUCTURAL STEEL MEMBERS DESIGNED TO CARRY LOADS AND PROVIDE
ADEQUATE RIGIDITY. STEEL STRUCTURES INVOLVE A SUB-STRUCTURE OR
MEMBERS IN A BUILDING MADE FROM STRUCTURAL STEEL. SOME FAMOUS STEEL
STRUCTURES ARE- WALT DISNEY CONCERT HALL,US TYNE BRIDGE,UK HOWRAH
BRIDGE,INDIA.
 STEEL, ALLOY OF IRON AND CARBON IN WHICH THE CARBON CONTENT RANGES
UP TO 2 PERCENT (WITH A HIGHER CARBON CONTENT, THE MATERIAL IS
DEFINED AS CAST IRON).
 ELEMENTS IN A STEEL STRUCTURE :
 STRUCTURAL MEMBER IS PHYSICALLY DISTINGUISHABLE PART OF STRUCTURE
WITH INDEPENDENT STRUCTURAL FUNCTION, E.G. MEMBER ELEMENTS ,CABLE
,BEAMS ,SECTION ETC.

3.  ADVANTAGES OF USING STEEL IN
STRUCTURES
 HIGH STRENGTH.
 THE HIGH RATIO OF STRENGTH TO
WEIGHT (THE STRENGTH PER UNIT
WEIGHT) EXCELLENT DUCTILITY AND
SEISMIC RESISTANCE.
 WITHSTAND EXTENSIVE
DEFORMATION WITHOUT FAILURE
EVEN UNDER HIGH TENSILE STRESS.
 ELASTICITY, UNIFORMITY OF
MATERIAL.
 PREDICTABILITY OF PROPERTIES,
CLOSE TO DESIGN ASSUMPTION.
 EASE OF FABRICATION AND SPEED OF
ERECTION.
ADVANTAGES OF USING STEEL IN
STRUCTURES
 SUSCEPTIBILITY TO CORROSION
 MAINTENANCE COSTS / THIN-WALLED
STRUCTURE
 LOSS OF STRENGTH AT ELEVATED
TEMPERATURE
 FIREPROOFING COSTS
 SUSCEPTIBILITY TO BUCKLING
 FATIGUE AND BRITTLE FRACTURE
BUCLING PHENOMENON

4. USES OF STEEL IN CONSTRUCTION:
 TO BUILD HIGH RISE BUILDINGS:
 STRUCTURAL STEEL IS RESISTANT TO EXTERNAL FORCES SUCH AS WIND AND EARTHQUAKES. IT IS
A FLEXIBLE METAL, SO IN THE CASE OF A STORM OR AN EARTHQUAKE, THE STEEL COMPONENT
IN THE BUILDING WILL NOT BREAK BUT BEND.
 TO BUILD INDUSTRIAL SHEDS:
ANOTHER BENEFIT OF STRUCTURAL STEEL IS THAT IT IS COST EFFECTIVE. WITH THE AVAILABILITY OF
READY-MADE STEEL SECTIONS, STRUCTURAL FRAMEWORKS CAN BE ERECTED IN NO TIME.
MOREOVER, A LOT OF WORK CAN BE PRE- DONE IN THE INDUSTRIAL SITE, THEREBY SAVING TIME
AND MONEY.
 TO BUILD RESIDENTIAL BUILDINGS:
THE PLASTICITY AND FLEXIBILITY OF STRUCTURAL STEEL MAKE IT SUITABLE FOR THE CONSTRUCTION
OF RESIDENTIAL BUILDINGS. A TECHNIQUE CALLED LIGHT GAUGE STEEL CONSTRUCTION IS USED TO
BUILD RESIDENTIAL BUILDINGS.
 TO BUILD BRIDGES:
STEEL HAS A HIGH STRENGTH TO WEIGHT RATIO, WHICH MEANS, STEEL IS A TENSILE METAL. IT
IS DURABLE AND CAN WITHSTAND THE WEIGHT OF A FLEET OF CARS AND PEOPLE.

5. HOWRAH BRIDGE
 THE CONSTRUCTION OF HOWRAH BRIDGE WAS FIRST
PROPOSED IN 1862 •LATER IN 1800S A FLOATING BRIDGE
WAS BUILT BETWEEN HOWRAH AND KOLKATA •THE
BRAITHWAITE BURN AND JESSOP CONSTRUCTION
COMPANY LIMITED WAS AWARDED THE CONSTRUCTION
CONTRACT.
 Specification :
 • IT IS SUSPENTION TYPE BALANCE CANTILEVER BRIDGE •
CENTRAL 457.5M SPAN • SUSPENDED 172M SPAN • MAIN
TOWERS ARE 85M HIGH • ANCHOR ARMS ARE 99.1M
EACH • BRIDGE DECK HANGS FROM 39 PAIRS OF
HANGERS • THE DECK SYSTEM INCLUDES CROSS GIRDERS
SUSPENDED BETWEEN THE PAIRS OF HANGERS BY A
PINNED CONNECTION.
 Two main expansion joints, one at each interface between
the suspended span and the cantilever arms • Total 8
articulation joints, 3 at each of the cantilever arms and 2
each in the suspended portion. • Deck has longitudinal
ruling gradient of 1 in 40 from either end • Bridge is joined
by a vertical curve of radius 4,000 feet (1,200 m).

6.  The bridge does not have nuts and bolts.
 • It consumed 26,000 tons of steel.
 • The two anchorage caisson were each 16.4m by 8.2m with two wells 4.9m square.
 • Set at 31.41m at Kolkata side and Howrah Side at 26.5m below the ground level.
 • Skin friction on the outside of the monolith walls was estimated at 29 km/m^2
 • loads on the cutting edge in clay reached 100 tones/m.
 • Work on the foundation was completed on November 1938. CONSTRUCTION The bridge does
not have nuts and bolts It consumed 26,000 tons of steel The two anchorage caisson were each
16.4m by 8.2m with two wells 4.9m square Set at 31.41m at Kolkata side and Howrah Side at 26.5m
below the ground level Skin friction on the outside of the monolith walls was estimated at 29
km/m^2 loads on the cutting edge in clay reached 100 tones/m Work on the foundation was
completed on November 1938.
 •It consumed 26,000 tons of steel.
 •The two anchorage caisson were each 16.4 X 8.2m with two wells 4.9m square.
 •The caisson set at 31.41m at Kolkata side and Howrah Side at 26.5m below the ground level.
 •The whole weight of the caisson to be carried by the outside skin friction and the bearing under
the external wall.
 •Work on the foundation was completed on November 1938.