structural engg_lec_19_introduction to bridge engineering
Post on 18-Dec-2015
43 Views
Preview:
DESCRIPTION
TRANSCRIPT
-
Course # CE-5154
03 Credit Hours
Lecture # 02+03
19 & 27-Mar-2011
Introduction to Bridge Engineering
Department of Civil Engineering,
University of Engineering & Technology, Peshawar, Pakistan
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 2Dr. Syed Mohammad Ali
Sequence of Presentation
What is Bridge?
Roles & Responsibilities of a Bridge Engineer
Types of Bridges & Bridge Components
Bridge Failure
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 3Dr. Syed Mohammad Ali
What is Bridge?
A1.2
Bridge is a structure that has the heaviest responsibility in carrying a free flow of traffic
Width of the bridge (number of lanes) dictates the traffic volume of a road segment
The Load Carrying Capacity of a bridge
would dictate the weight of truck allowed
to cross the bridge (load limits can be
posted )
Thus bridge controls both capacities: The volume and
Weight of the traffic of the transportation system.
Golden Gate Bridge California
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 4Dr. Syed Mohammad Ali
What is Bridge?
The most costly component of Transportation network
Currently ~6,000 bridges on Natl. Highways ~Rs. 400-700 bn asset (NHA bridges only)
NHA budget FY 2009-10 was ~Rs.39.9 bn
(6.2% of PSDP Rs.646 bn) [Min. of Fin. 2009]
4411,000
500
3,500
7031,262
631
4,419
0
1,000
2,000
3,000
4,000
5,000
New Khiarabad Brdg. (2003)
Indus Brdg M1 (2007)
Kabul River Brdg M1 (2007)
Northern Bypass (2007)
Co
st in
Mill
ion
sP
KR
Value in Respective Year
NPV 2011
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 5Dr. Syed Mohammad Ali
Roles and Responsibilities of a Bridge Engineer
Safe and Economical Design
The bridge engineer is often involved with several or
all aspects of bridge planning, design, & management
This situation is not typical in the building
Architect usually heads a team (architects, civil,
structural, mechanical, & electrical engineers)
In the bridge engineering, the bridge engineer works
closely with other civil engineers (roadway alignment
and design)
After the alignment is determined, the engineer
often controls the bridge type, aesthetics, and
technical details
The bridge engineer has significant control over The design,
construction, and
maintenance processes
Sher Shah Bridge Collapse 2007Karachi
Hen-Shen Expwy Japan , Kobe EQ6.9 Mw, 1996
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 6Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Broad Classification of Bridges
Bridge Classification
Material
Steel Concrete Wood Hybrid Stone/Brick
Usage
Pedestrian Highway, Railroad, Aircraft
Structural Form
Slab Girder Truss Arch Suspension
Cable-Stayed
Type Traffic
Highway, Pedestrian, trains, transit, others
Span
Short , Medium & Long
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 7Dr. Syed Mohammad Ali
Classification According to Traffic
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 8Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Classification as per Structural Form
Girder Bridge
Arch Bridge
Truss Bridge
Suspension Bridge
Cable-Stayed Bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 9Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Girder Bridge Most commonly constructed
Usually used for Short and Medium spans (up to 50 m)
Structural Action is to carry load in Shear and Flexural
Economical and long lasting solution for vast majority of bridges
Decks and girder usually act together to support the entire load in highway bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 10Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Girder Bridge
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 11Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Typical Deck Super-structures Table A4.6.2.2.1-1
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 12Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Typical Deck Super-structures Table A4.6.2.2.1-1
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 13Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Typical Deck Super-structures Table A4.6.2.2.1-1
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 14Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Typical Deck Super-structures Table A4.6.2.2.1-1
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 15Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Typical Deck Super-structures Table A4.6.2.2.1-1
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 16Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Span lengths for various types of Super-structures
Ayub Bridge Havalian, KKH
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 17Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Arch Bridges
Arch action reduces flexural stresses (that is Tensile Stresses )
Arch is predominantly a compression member. Buckling needs attention.
Can be economical as compared to equivalent straight simply supported girder or truss bridge
Suitable site would be Valley which has strong foundations on a rocks
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 18Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Arch Bridges
Generally conventional curved arch rib has high fabrication & erection costs
Erection easiest for Cantilever Arch and most difficult for Tied Arch
Bridge in Neelum Valley, AJKIs it an Arch?
Tied Arch
Wooden Arch Bridge, Rocky Mountains, Colorado, USA
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 19Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Arch Bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 20Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Truss Bridges
The primary member forces are axial tension or compression
The open web system allows deep girders than for an equivalent solid web girder
This may lead to economy in material and reduced dead weight
The cost of fabrication and maintenance is high
The truss is attractive choice in suspension bridges due to its superior aerodynamic behavior
Truss results in light structure that can be assembled member by member using small lifting capacity equipment
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 21Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Truss Bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 22Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Suspension Bridges
Major element is a flexible cable, that transfers the loads to the towers and anchorage
This cable is from High Strength wires
The deck is hung from the cable by Hangers also of high strength ropes (in tension)
Suitable for very long spans
Expensive to build and maintain
Totakan (near Swat)Thakot Bridge over River Indus Golden Gate Bridge California
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 23Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Cable-Stayed Bridges
In comparison to suspension bridge, the cables are straight rather than curved. Therefore the stiffness is greater
The cables are anchored to the deck
All individual cables are shorter than full length of the superstructure.
Economical over 100-350m, some bridges are as long as 800m
No such bridge built in Pakistan as yet but one is in construction phase in AJK, work on one started in Muzaffarabad, AJK
Naluchi, Muzaffarabad, AJk
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 24Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Classification with respect to Span
Small Span Bridges up to 50 feet (15m)
Medium Span Bridges up to 250 feet (75m)
Large Span Bridges 150-500 feet (50-150m)
Extra Large ( Long ) Span Bridges over 500 feet (150m)
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 25Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Small Span Bridges up to 50 feet (15m)
Culverts
Slab Bridges 40 ft (12m)
T-Beam Bridge 30-60 ft (10-20m)
Wood Beam Bridge
_________________
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 26Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Medium Span Bridges up to 250 feet (75m)
Pre-cast Concrete Box Beam Bridge 30-150 ft (10-50m)
Rolled Steel Beam Bridge up to 100 ft (30 m)
Pre-cast Concrete I-Beam Bridge 30-150 ft (10-50m)
Cast-in-place RC Box Girder Bridge (20-40 m)
Composite Steel Box Girder
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 27Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Large Span Bridges 150-500 feet (50-150m)
Composite Steel Plate Girder Bridge
Cast-in-place Post-Tensioned concrete Box Girder
Post-Tensioned Concrete Segmental Construction
Concrete Arch and Steel Arch
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 28Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Extra Large ( Long ) Span Bridges over 500 feet (150m)
Cable Stayed Bridge
Suspension Bridge
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 29Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Structural Arrangement
Bridge types can also be classified according to the location of the main structure elements relative to the surface on which the user travels:
Main Structure Below the Deck Line
Main Structure Above the Deck Line
Main Structure coincides with the Deck Line
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 30Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Structure Below the Deck Line
Arch Bridges
Truss-Arch Bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 31Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Structure Above the Deck Line
Suspension Bridges
Cable Stayed Bridges
Through-Truss Bridges
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 32Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Structure coincides with the Deck Line
Slab (solid and voided)
T-Beam (cast-in-place)
I-beam (pre-cast or pre-stressed)
Wide-flange beam (composite & non- composite)
Concrete Box (cast-in-place, segmental & pre-stressed)
Steel Plate Girder (straight & haunched)
Steel box (Orthotropic deck)*
*An orthotropic bridge or orthotropic deck is one whose deck typically comprises a structural steel deck plate stiffened either longitudinally or transversely, or in both directions. This allows the deck both to directly bear vehicular loads and to contribute to the bridge structure's overall load-bearing behavior. The orthotropic deck may be integral with or supported on a grid of deck framing members such as floor beams and girders.
The same is also true of the concrete slab in a composite girder bridge, but the steel orthotropic deck is considerably lighter, and therefore allows longer span bridges to be more efficiently designed.
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 33Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Components
Girders
Guard Rails
Pier / column
Transom / Pier Cap
Diaphragms
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 34Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Components
Guard Rails
Pier / column
Abutment
Abutment
Piles
Pile Cap
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 35Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Components
Pile Cap
Piles
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 36Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Components
Bearing Pad
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 37Dr. Syed Mohammad Ali
Types of Bridges & Bridge Components
Main Components
Multi-column Pier
Isolator / Base Isolator
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 38Dr. Syed Mohammad Ali
Bridge Failures
Bridges do Fail!
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 39Dr. Syed Mohammad Ali
Bridge Failures
Bridges do Fail!
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 40Dr. Syed Mohammad Ali
Bridge Failures
Bridges do Fail!
-
CE-5154 Intro. to Bridge Engg.Lecture # 02 Email: ali@civionics.pk20-Mar-2011 41Dr. Syed Mohammad Ali
Q & A
Thanks!
top related