Graduation Project Unit

frizzflowerΠολεοδομικά Έργα

29 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

75 εμφανίσεις

United Arab Emirates University

Collage of Engineering

Graduation Project Unit


Bakheet Ahmad Al
-
Mansoori 200101695


Khalfan Ahmad Al
-
Mansoori 200101697


Saeed Nasser Al
-
Ahbabi 200101684


Saif Rashid Al
-
Mansoori 200101629

First Semester

2006
-

2007

Contents


Introduction


Background theory


Structural systems


Design calculation


Cost calculation


Results and discussion


Conclusion and recommendations






Introduction



Al

Jazira

Mohammed

Bin

Zayed

Stadium

is

a

multi
-
use

stadium

in

Al

Jazira

Club

located

in

Abu

Dhabi
.




The

stadium’s

original

capacity

was

15
,
000

seats

but

it

is

currently

going

through

an

expansion

stage

which

will

increase

the

stadiums

capacity

to

an

all

seated

40
,
000

ultra
-
modern

air

conditioned

sporting

arena
.




The

expansion

program

includes

two

residential

towers

to

be

built

beside

the

stadium

and

three

phases

the

first

two

phases

are

carried

out

using

reinforced

concrete

and

pre
-
cast

concrete

structures

whereas

the

third

phase

is

designed

using

structural

steel

systems
.


Introduction


This

project

focuses

analysis

and

design

of

alternative

structural

systems

to

the

future

phase

three

of

Al

Jazira

stadium
.




The

actual

structural

system

to

be

used

in

construction

of

phase

three

consists

of

an

overhang

steel

roof

truss

supported

by

a

framed

column,

which

is

in

turn

supported

at

the

top

of

phase

two
.

GP
1
overview


We design two alternative
structural systems are proposed in
the current project.




First system
, is a simple truss
system which consists of overhang
steel roof trusses supported by
trussed columns.



Second system
is a modification of
the former one by extending the
height of the trussed column above
the roof level to allow for
installation of cables that are
attached from the other end to the
mid
-
points of the roof trusses.

Graduation Project (II)


calculating

the

structural

loads

acting

on

system

(
2
),

modeling

and

analysis

of

both

system

(
1
)

and

system

(
2
)

using

SAP
2000

software
.



Designing

and

detailing

the

analyzed

systems

according

to

the

LRFD

version

of

the

AISC

code
.




Developed

Excel

spreadsheets

to

facilitate

the

design

of

the

high

numbers

of

structural

elements

and

connections

included

in

the

proposed

systems
.

Structural

details

were

presented

using

AutoCAD
.



Background Theory



Steel



Types of loads



Load combination



SAP
2000

Steel

1.

The aim

of using steel is to reduce the dead weight.

2.

Composed of
Iron
, Small amount of
Carbon
(<
2
%) and other chemical
components (such as
Manganese, Copper, Nickel, Silicon, and Aluminum
)

3.

The aim

of the chemical components is to improve
strength
,
toughness
,
hardness
,
ductility
, and
corrosion resistance
.

4.

Increasing the
Carbon content

leads to an increase in
strength

and
hardness
, but decreases ductility and toughness.

5.

Strength and Ductility

are the most
important characteristics

of structural
steel.

6.

Ductility

is the ability of the member to undergo large deformations without
fracture.

7.

The
economical production

method began around the
middle of the
19
th
century
, by heating iron in contact with charcoal.

8.
A more
advanced process

was introduced by
Sir Henry Bessemer

of England
in
1855
(the
Bessemer process
).

Steel


Advantages of construction steel:


-

High strength
-
to
-
weight ratio.

-

Ductility (large deformation before failure).

-

Flexibility in structural forms.

-

Long lifetime if properly maintained.

-

Recyclable material, environmental friendly.


Disadvantage of construction steel:


-

Buckling susceptibility.

-

Fireproofing cost, to prevent transmission of heat and the associated large

reduction in strength.

-

High maintenance cost, e.g. paint coating.

-

Higher construction and maintenance cost in some parts of the world.


Steel Specification




The type of steel that was used in this project is (High strength Low
-
alloy) A
572



Grade
60
, Fy =
60
ksi , Fu =
75
ksi.



It gives a high resistance with acceptable cross section dimensions, especially
for large span structures.



Circular cross sections were used in this project.

Types of load



Dead load



Live load



Wind load



Live roof load

Load combination


1.4
D










1.2
D +
1.6
L +
0.5
(L
r

or S or R)









1.2
D +
1.6
(L
r

or S or R) + (
0.5
L or
0.8
W)






1.2
D +
1.3
W +
0.5
L +
0.5
(L
r

or S or R)






1.2
D
±

1.0
E +
0.5
L +
0.2
S








0.9
D
±

(
1.3
W or
1.0
E)


Where:


D = Dead load

L = Live load

W = Wind load

E = Earthquake load

L
r

= Roof Live Load

SAP
2000



SAP
2000
is a
finite element
-
based

software that represents the most sophisticated
and user
-
friendly release of the SAP series of computer programs.



Powerful
graphical user interface

unmatched in terms of ease
-
of
-
use and
productivity.



This program features powerful and completely
integrated modules

for design of
both
steel and reinforced

concrete structures.



The program provides an
interactive environment

in which the user can study the
stress conditions, make appropriate changes, such as member size revisions, and
update the design without re
-
analyzing the structure.

Structural systems


Structural system(
1
):


it is consist of trusses only, and divided into three
parts, column, shed and rakar as present in below figure:



Structural system(
2
):



it is consists of trusses and cable also have a
same divination of system(
1
), However, it should
be noted that the column height was increased
to allow for the installation of the cable element
connected to the middle of the overhang as
shown in following figure.

Modeling, analysis and design procedure for
both system



The geometry of the proposed systems was generated in
Auto Cad.



the coordinates corresponding to each nodal point were
identified.


Such information along with joints are members
numbers, tables of cross section dimensions, applied
loads and load combinations are entered into the
SAP
2000
program.


The cable properties should be take it from cables
factory otherwise, is not available in SAP
2000
program.

Design calculations

Tension members design


Design Requirements for tensions members:
-


Pu
Pn


Strength can be determined based on
3
potential failure modes
in our project:
-



-

Yielding of the Gross Section.



-

Fracture of the Net Section.



-

Stiffness for Tension Members.


Where:




Ø

is the resistance reduction factor:
-



=
0.90
for yielding failure.



=
0.75
for fracture failure.




P
n


is the nominal strength of the tension member.




P
u

is the factored tensile force.


Tension members design


Strength can be determined based on
3
potential failure
modes in our project:
-







-

Yielding of the Gross Section.




-

Fracture of the Net Section.




-

Stiffness for Tension Members.


Yielding of the Gross Section:
-


Tension members design




t
P
n

=
0.9
F
y

A
g


Where:




F
y


is the yield stress of steel used,



A
g

is the gross area of the tension member cross
-
section



(A
g

=
π

* (D
out



D
in
)
2
/
4
).



Where:




F
u


is the ultimate tensile stress of steel.




A
e

is the effective net area at the critical section.


Tension members design


Fracture of the Net Section

:
-


ØP
n
=
0.75
F
u
A
e

A
e

= A
n

U


Where:



A
n


is the net area at the critical section



=
A
g



[
(D
out



D
in
) * t
Gusset Plate
],





U is a reduction factor due to the shear lag effect when not all


the x
-

sectional area is directly connected to the joint



(U =
1
for our project).

Excel Spreadsheet For Design of Tension
members


Compression members design


Pu
Pn


Design Requirements:
-


Where:




Ø

is the resistance reduction factor:



=
0.85
.




P
n


is the nominal strength of the tension member.




P
u

is the factored tensile force.


Where:




F
cr


critical buckling stress.




A
g

gross area of the member .




g
cr
n
A
F
P
85
.
0


Compression members design


First of all we have to calculate the slenderness coefficient:
-


E
F
r
KL
y
c


/

Where:




λ
c

= slenderness coefficient



Fy

= yield stress (ksi)




E

= modulus of elasticity (ksi)



K

= effective buckling length factor



L

= laterally unbraced length of member (in)



r

= governing radius of gyration about the axis of buckling (in)

Compression members design


Compare to the value of
1.5
, If is greater than
1.5
then the critical elastic
buckling stress is given by
:
-


y
c
cr
F
F
.
877
.
0
2










And if is less than
1.5
then the critical inelastic buckling stress is given
by:
-

y
cr
F
F
c
.
)
658
.
0
(
2


Compression members design


Local buckling

can be avoided only if the
width
-
to
-
thickness ratio

(b/t) of
each element in the cross section of the column does not exceed a
specific value called
λ
c
.

The following figure summarizes the two cases of elastic and inelastic
overall buckling:

Figure : Elastic and inelastic buckling of columns


Excel Spreadsheet For Design of Tension
members


Zero members



Members doesn’t carry any load.



check the stiffness.



L/r
<

200


Where:

-

L : the length of the member.

-

R : the radius of the member.

Zero members

Welded connections design


Use SMAW process, and E
80
electrodes.


F
exx

=
80
Ksi


t
(G.PL)

=
0.5
in


F
y

=
60
Ksi


F
u

=
75
Ksi

Welded connections design



Strength of Longitudinal weld:



Weld fracture:

ΦR
n
/in =
0.75
(
0.6
F
exx
)(
0.707
S
w
)




Shear rapture of the member:


ΦR
n
/in =
0.75
* (
0.6
F
u
) *t
member




Shear rapture of gusset plate:

Φ
R
n
/in =
0.75
(
0.6
F
u
)* t
(G.PL)

Welded connections design

Bolted connection design


In the construction site either welding or bolting could be used;
however, bolting is more recommended for quality control, ease and
safety reasons.

Bolted connection design:

There is two typical types of high strength
bolts are commonly used, A
325
and A
490
.

Fv

(ksi)

Bolt type

48

A
325
N

60

A
325
X

60

A
490
N

75

A
490
X

Bolted connection design


High strength bolts can be used to form two
main types of connections,
Shear failuer in Bolts

and Bearing Failure at Bolt Holes

depending on
the load transfer mechanism of each connection
type.


In
Shear failuer in Bolts

:


R
n

≥ P
u



R
n


=
0.75
F
v
A
gv

N
b

N
s


Bearing Failure at Bolt Holes

:



At the external bolts:
-




Since Le =
2
in >
1.5
d




t = smaller of:


1
-

t =
0.5
in (gusset plate)






2
-

t = (
2
*
3
/
8
) in (splice plate)


ØP
n
/bolts =
0.75
(
2.4
)(d)(t)Fu



At the internal bolts:
-



Since S =
3
d


so,







ØP
n
/bolts =
0.75
(
2.4
)(d)(t)Fu






The factored bearing resistance of the connection:



ØPn

= [(number of external bolts * ØPn/bolts
for the external
) + (number of



internal bolts * ØPn/bolts
for the internal
)]


Beam design


The design of beam which stand on
trusses joint of system and carried the
concrete slab.


The all beams are a same in the design for
both systems.

22.08
ft

w


The beam is rotated by
31
dgree around the
globule axis.


It is effected by previews types of load.


The beam should be design to resist the
moment and shear.


The moment which govern the design should be
the maximum moment of moment due by
different types of load combination.


The beam should be design to resist the
moment and shear.


The moment which govern the design
should be the maximum moment of
moment due by different types of load
combination.


Find:

Max. M
x


Max. M
y



Beam section selecting:


Assume: L
b
=L=
22.08
ft



steel type used is Fy=
50
ksi


C
b
=
1.14


From LRFD manual
-
beam sections charts

We find the beam section according Max.M
u
and beam length.


Then find
corresponding design
moment


















p
nx
n
n
b
M
M
Cb
of
smallest
x
M
x
M
*

Design moment in y
direction





Moment check:
















Fy
Sy
Fy
Zy
of
smallest
y
M
n
*
*
5
.
1
*
9
.
0
*
*
9
.
0
1
.
0
.
.




y
M
My
Max
x
M
Mx
Max
n
n

Shear check:

max
max
2
*
5
.
0
3
.
1
2
.
1
V
Vn
L
W
V
combo
load
W
W
W
LX
WX
DX





Base connection




The design for connection between
the trusses system and concrete slab:

Base Plate Dimensions:
-



a =
2
Ø
b


b = L
e


L
min

= D
out

+
2
a +
2
b


Where:
-


D
out
: outer diameter of member.




Ø
b
: diameter of bolt.

Base connection

y
c
c
y
F
f
b
a
t
b
a
b
a
L
f
t
L
F
Mu
Mn
'
'
2
27
.
2
)
(
2
)
(
)
(
*
*
02
.
1
)
2
/
(
*
*
*
9
.
0







-

Check bearing stress on the concrete slab below the base plate:
-

'
2
02
.
1
c
Z
f
L
R

-

For determine the base plate thickness:
-

Where:
-


t

= base plate thickness


R
z

= compression force.


F
y

= area of bolt.




= diameter of bolt
.

'
c
f
Base connection

Anchor bolts:
-



-

The bolt is subjected to tension and shear:



-

For shear:
-


V
V
V
V
b
V
F
f
F
F
nA
V
f





*
75
.
0
Where:
-


V

= shear force.


A
b

= area of bolt.



n

= number of bolt.

Base connection

Anchor bolts:
-



-

The bolt is subjected to tension and shear:



-

For tension:
-


t
t
t
t
V
V
t
V
t
V
b
u
t
F
f
F
F
f
f
F
f
F
f
nA
T
f















)
90
(
75
.
0
90
90
9
.
1
117
)
9
.
1
117
(
75
.
0
9
.
1
117
90
9
.
1
117
Where:
-


T
u

= tension force.


A
b

= area of bolt.


n

= number of bolt.


systems cost


Systems weight calculation:



1
-
calculated the volume for each
member.


V=(D
out


D
in
)
*
L
member



2
-
calculated the weight for each
member. W= V*Specific weight of steel


Cost Calculated:



the cost of steel =
6500
Dhs/ton


the total cost = total weight(ton)*cost / ton


system(
1
) cost =
6.30371
ton*
6500
Dhs/ton
=
40.974
Dhs


system(
2
) cost =
6.41431
ton*
6500
Dhs =
41.693
Dhs.

Results and Discussion



System
1
is better than system
2
because its economically.




The trusses must be welded in the factory.




The transportation process must be under the observation of the Consultant to
avoid any damages to the parts.


conclusion & Recommendation


Analysis and preliminary design proposed systems by
used SAP
2000


Tension and compression members manually design.


Welded and bolted connection design.


Zero members design.


Beam design.


Base connection design.


Cost calculation for both system.


At the end of GP
2
we recommend our collage to give the
student different courses of structural soft war .