This document provides an overview of steel structures including: 1. It defines steel structures as structures designed to fulfill their intended purpose during their lifetime by being adequately safe, serviceable, economical, and environmentally friendly. 2. It discusses the historical development of steel structures from early human shelters made of natural materials to modern steel structures regulated by specifications that have grown more complex over 100 years. 3. It outlines some key topics that will be covered related to steel structures including types of structural steel, types of steel structures, construction methods, current technologies, and the history of steel structures.

1. Steel Structures
Group 15
Ali Bakjaji
Abdallah Moustafa
Rasha Alshakran
CE 102 Introduction to civil engineering
Tanay Karademir
30-May-16

2. 2
Contents
Contents ............................................................................................................................................................ 3
Introduction to Steel Structures:......................................................................................................................... 4
Definition of Steel Structures:............................................................................................................................ 5
Historical development:..................................................................................................................................... 6
Types of structural steel:....................................................................................................................................7
Types of steel structures: ...................................................................................................................................8
Constructions of steel structure:....................................................................................................................... 10
Conclusion: ..................................................................................................................................................... 11
Bibliography.................................................................................................................................................... 12
Table 1 Types of steel and there relevant IS standards ....................................................................................... 7
Table 2chemical compositions (in percentage) of some typical structural steel................................................... 7
Table 3Sequence of Activities during Erection................................................................................................. 11
Figure 1: A truss bridge across Ohio River........................................................................................................ 9
Figure 2: typical rigid frame construction .......................................................................................................... 9
Figure 3: shear wall construction .................................................................................................................... 10

3. 3
Introduction to Steel Structures:
In early societies, human beings lived in caves and almost certainly rested in the shade of trees.
Gradually, they learnt to use naturally occurring materials such as stone, timber, mud, and
biomass (leaves, grass, and natural fibers) to construct houses. Then followed brick making, rope
making, glass, and metal work. From these early beginnings. The modern materials
manufacturing industries developed.
The principal modern building materials are masonry, concrete (mass, reinforced, and
prepressed), glass, plastic, timber, and structural steel (in rolled and fabricated sections). All the
mentioned materials have particular advantages in given situation and hence the construction of
a particular building type may involve the use of various materials, e.g., a residential building
may be constructed using load-bearing masonry, concrete frame or steel frame. The designer has
to think about various possible alternatives and suggest a suitable material which will satisfy
economic, aesthetic, and functional requirements.
The main advantages of structural steel as a building material are its strength, speed of erection,
prefabrication, and demountability. They are used in load-bearing frames in buildings, and as
members in trusses, bridges, and space frames. Steel, however, requires fire and corrosion
protection. In steel buildings, claddings and dividing walls are made up of masonry or other
materials, and often concrete foundation is provided. Steel is also used in conjunction with
concrete in composite constructions and in combined frame and shear wall constructions. In many
cases, the fabrication of steel members is done in the workshop and the members are transported
to the site and assembled. Tolerances specified for steel fabrication and erection are small
compared to reinforced concrete structures. Moreover, welding, tightening of high-strength
friction grip bolts, etc., require proper training. Due to these factors, steel structures are often
handled by trained workers and assembled with proper care, resulting in structures with better
quality. Steel offers much better compressive and tensile strength than concrete and enables

4. 4
lighter constructions. Also, unlike masonry or reinforced concrete, steel can be easily recycled.
(Subrmanian, 2010).
In this paper definition, types, construction methods, current technology, and the history of steel
structures and structural steel’s history will be included.
Definition of Steel Structures:
Structural design, though reasonably scientific, is also a creative process, the aim of a structural
designer is to design a structure in such a way that it fulfils its intended purpose during its intended
lifetime and be adequately safe (in terms of strength, stability, and structural integrity), and have
adequate serviceability (in terms of stiffness, durability, etc.). In addition, the structure should be
economically viable (in terms of cost of construction and maintenance), aesthetically pleasing,
and environment friendly.
Safety is of paramount important in any structure, and requires that the possibility of collapse of
the structure (partial or total) is acceptably low not only under normal expected loads (service
loads), but also under less frequent loads (such as due to earthquakes or extreme winds) and
accidental loads (blasts, impacts, etc.). Collapse due to various possibilities such as exposure to
a load exceeding the load bearing capacity, overturning, sliding, buckling, fatigue fracture, etc.
should be prevented.
Another aspect to safety is structure integrity and stability—the structure as whole should be
stable under all conditions. (Even if a portion of it is affected or collapsed, the remaining parts
should be able to redistribute the loads.) in other words, progressive failure should be minimized.
Serviceability is related to the utility of the structure—the structure should preform satisfactory
under service loads, without discomfort to the user due to excessive deflection, cracking,
vibration, etc. other considerations of serviceability are durability. Impermeability, acoustic and
thermal insulation, etc. it may be noted that a design that adequately satisfies the safety
requirement need not satisfy the serviceability requirement. Increase the design margins of safety
may enhance safety and serviceability, but increase the cost of the structure. For overall economy

5. 5
one should look into not only the initial cost but also the life-cycle cost and the long-term
environmental effects. For example, using a very-high-strength steel to reduce weight often will
not reduce cost because the increased unit price of high-strength steel will make the lighter design
more costly. In bridges and buildings the type of corrosion and fire protection selected by the
designer will greatly influence the economy of the structure.
While selecting the material and system for the structure the designer has to consider the long-
term environmental effects. Such effects consideration include maintenance, repair and retrofit,
recyclability, environmental effects of the demolished structure, adoptability of the fast track
construction, demountability, and dismantling of the structure at a future date.
Historical development:
The structural steel industry is over 100 years old. During that time, steel structures and the
technical specifications governing their design have become more and more complex. The
American Institute of Steel Construction (AISC), founded in 1921, developed the first standard
Specification for the Design, Fabrication and Erection of Structural Steel for Buildings in 1923.
This original document was 8 pages long. The AISC specifications have evolved through
numerous versions, and the latest (ninth) edition was published in 1989. Known as Allowable
Stress Design Specifications (ASDS), this document is 103 pages long. In 1986 AISC introduced
the first of a new generation of specifications based on reliability theory, and this document is
named Load and Resistance Factor Design Specification (LRFDS). The third edition (December
1999) of the LRFDS is 169 pages long. Thus, in earlier days, specifications and standards used
to be relatively thin documents that contained the basic essentials of a subject and were easy to
assimilate and use. Growth in knowledge due to research and testing, and introduction of new
steels, high strength bolts, and welding, has enabled far more complex structures to be built, and
availability of computers has enabled far more rigorous analyses to be made, leading to more
detailed and lengthy specifications. As correctly pointed out by Professor Hatfield, (AISC, 1992)
"Technical knowledge grows, rather than being superseded. Every generation of engineers, and
of engineering graduates, is expected to know more than its predecessor. Meeting these

6. 6
expectations requires adding topics and courses rather than replacing the old with the new.” In a
paper that won him the 1992 AISC T.R. Higgins Leadership Award, Professor McGuire observed:
"It is the nature of steel structures that all of their strength limit states--except fatigue, fracture,
and tension member failure-- are in fact stability limits. An engineer should have an
understanding of the various manifestations of this complex phenomenon as well as the scope
and limitations of the classical and contemporary schemes used for dealing with them." In effect,
the strength limit states are inelastic stability limits. (AISC, 1992).
Types of structural steel:
Chemical composition of steel:
Several varieties of steel are produced in India. The Bureau of India Standards (BIS) classifies
structural steel into different categories based on the ultimate yield strength of basic material and
their use. They are listed along with the appropriate codes of practice issued by BIS in Table 1.1.
Table 1 Types of steel and there relevant IS standards
Types of steel Relevant IS standards
Structural steel 2062,1977,3520,5517,8500
Steel for tubes and pipes 1239,1941,806,1161,10748,4932
Steel for sheets and strips 27,1079,12367,513,12313,14246
Steel for bolts, nuts, and washers 1363,1364,1367,3640,3757,6623,6639,730,4000,
5624,6649,8412,10238,12427
Welding 814,1395,816,819,1024,1261,1323
Steel for filer rods/wires, electrodes 1278,1387,7280,6419,6560,2879,4972,7280
Steel casting 1030,2708,2644,276
The chemical compositions of some typical steel specified by the BIS are listed in Table 1.2. For
details of chemical composition of other steels refer IS 1977 [structural ordinary (low tensile)
quality]. IS 8500 (medium and high strength quality). (N. Subrmanian, 2010)

7. 7
Table 2chemical compositions (in percentage) of some typical structural steel
Type of
steel
Design
ation
IS
code
C
(max.)
Mn
(max.)
S
(max.)
P
(max.)
Si
(max.)
Carbon
equivalent
Standa
rd
Fe 410
Aa
2062 0.23 1.5 0.050 0.050 -- SKb
0.42
Structu
ral steel
Fe 410
B
Fe 410
C
2062
2062
0.22
0.20
1.5
1.5
0.045
0.040
0.045
0.040
0.40
0.4
SK
K
0.41
0.39
Micro- Fe 440 8500 0.20 1.3 0.050 0.050 0.45 0.40
Alloyed Fe 540 8500 0.20 1.6 0.045 0.045 0.45 0.44
Mediu
m-
/high-
strengt
h steel
Fe 590 8500 0.22 1.8 0.045 0.045 0.45 0.48
Types of steel structures:
There is no unique way to classify structural elements and systems. If the geometry of the
structure system or element is used as the basis for classification. Structural elements are either
discrete or continuous. Discrete elements are those that can be geometrically approximated as
one-dimensional entities. Examples of discrete elements include trusses, frames, cables, and
arches. Continuum structures are those in which the material distribution can be geometrically
expressed in two-dimensional or three-dimensional space. Examples include plates and shells.
Truss: the simplest member is a short, prismatic, slender, and straight member. A truss is founded
by connecting these members to one another with pin connections (fig. 1). In two-dimensions,
the resulting structure usually consists of a pattern of triangles. When the structure is loaded, the

8. 8
members are subjected to only axial forces. The members are either in axial tension or
compression. There are no shear forces or bending moments in a truss member.
Figure 1: A truss bridge across Ohio River
Frames: framed structures are formed by members connected to one another with rigid or semi-
rigid connections. The horizontal member are usually referred to as beams (some of the other
frames used for beams are rigid, joist, purlin, lintel), while the usually vertical members are
columns. Frames can be very efficient in resisting gravity and lateral loads. Under the action of
these loads, the beams are subjected primarily to bending moments, whereas the columns carry
axial forces. As with truss members, the length of individual beams and columns is limited. The
members are slender and prismatic however, the members can be straight or curved (fig. 2).
Figure 2: typical rigid frame construction

9. 9
Shear walls: This type of lateral load resisting system engages a vertical element of the building,
usually concrete or masonry, to transfer the horizontal forces to the ground by a primary shear
behavior. Shear walls are usually longer than they are high and are inherently stiff elements.
Careful attention to detailing the joint between the shear wall and floor or roof diaphragm
elements may be required. Code-specific spacing of masonry shear walls may also impact the
interior layout of the building. (Rajan, 2001)
Figure 3: shear wall construction
Constructions of steel structure:
Erection of steel structures is the process by which the fabricated structural members are
assembled together to form the skeletal structure. The erection is normally carried out by the
erection contractor. Generally the steps that are involved in the erection of steel structures are
shown in Table 3. The erection process requires considerable planning in terms of material
delivery, material handling, member assembly and member connection. Proper planning of
material delivery would minimize storage requirement and additional handling from the site
storage, particularly heavy items. Erection of structural steel work could be made safe and
accurate if temporary support, falsework, staging etc. are erected. Before erection the fabricated
materials should be verified at site with respect to mark numbers, key plan and shipping list. The
structural components received for erection should be stacked in such a way that erection

10. 10
sequence is not affected due to improper storing. Care also should be taken so that steel structural
components should not come in contact with earth or accumulated water. Stacking of the
structures should be done in such a way that, erection marks and mark numbers on the
components are visible easily and handling do not become difficult. From the earlier discussion
it should emphasised that safe transportation of fabricated items to the site, their proper storage
and subsequent handling are the pivotal processes for the success of fabrication of structural steel
work.
Table 3Sequence of Activities during Erection
S.NO. SEQUENCE OF OPERATION
1. Receiving material from the shop and temporarily stacking them, if necessary.
2. Lifting and placing the member and temporarily holding in place.
3. Temporarily bracing the system to ensure stability during erection
4. Aligning and permanently connecting the members by bolting or welding.
5. Connecting cladding to the steel structural skeleton.
6. Application of a final coat of painting.
A variety of methods can be employed for the erection of a structure. Normally, the selection of
the method is influenced by the type of the structure, site conditions, equipment, quality of skilled
labour, etc. available to the erector.
However, regardless of the method adopted the main aim during erection is the safety and
preservation of the stability of the structure at all times. Most structures which collapse do so
during erection and these failures are very often due to a lack of understanding on someone's part
of what another has assumed about the erection procedure. Hence, it is emphasized that as far as
strength and stability of the components during erection are concerned, they must satisfy the
provision of IS: 800(1984). For the guidance on general fabrication and erection of structural steel
work, Chapter 11 of IS: 800 (1984) must be followed. As far as safety is concerned guidance
could be obtained from Indian safety code for structural steelwork IS: 7205(1974). Before the
commencement of the erection, all the erection equipment tools, shackles, ropes etc. should be

11. 11
tested for their load carrying capacity. Such tests if needed may be repeated at intermediate stages
also. (G.w, 1994)
Conclusion:
The steel-framed building derives most of its competitive advantage from the virtues of
prefabricated components, which can be assembled speedily at site. Unlike concreting, which is
usually a wet process conducted at site, steel is produced and subsequently fabricated within a
controlled environment. This ensures high quality, manufacture offsite with improved precision
and enhanced speed of construction at site. The efficiency of fabrication and erection in structural
steelwork dictates the success of any project involving steel-intensive construction. Current
practices of fabrication and erection of steel structures in India are generally antiquated and
inefficient. Perhaps, this inadequate infrastructure for fabrication is unable to support a large
growth of steel construction. In India, the fabrication and erection of structural steelwork has been
out of the purview of the structural designer. Nevertheless, in the future emerging situation, the
entire steel chain, i.e. the producer, client, designer, fabricator and contractor should be able to
interact with each other and improve their efficiency and productivity for the success of the
project involving structural steelwork. Hence it becomes imperative that structural designers also
must acquaint themselves with all the aspects of the structural steel work including the
“fabrication and erection,” and that is the subject matter of the present chapter to briefly introduce
good fabrication and erection practices.
Bibliography
AISC, 1992. Computes and Steel Design, Engineering Journal, 29(04), pp. pp. 160-169..
AISC, W. f. E., 1992. Preliminary Survey of Undergraduate Instruction in Steel Design.
G.w, O., 1994. Steel Designers manual. 5th ed. london: ELBS blackwall scientific publishers.
N. Subrmanian, 2010. Steel Structures. s.l.:oxford university press.
Rajan, S. D., 2001. Introduction to structural analysis and designe. s.l.:s.n.