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CE 414 Introduction to Bridges Engineering
Asst Prof Mansoor Khalid
COURSE OUTLINE CE 414: BRIDGE ENGINEERING Fall Semester 2013 PREREQUISITES: CE 206 – Structural Analysis I, CE 307 Structural Analyses II, CE 309 Structural Analyses III, CE 446 – Reinforced Concrete Design CE 411 – Steel Structures TEXTBOOK: R.S.Rakshit, Design and construction of highway Bridges: 2004. (For IRC and WPHCB provisions) Taly, N. Design of Modern Highway Bridges, McGraw Hill, 1998 (For AASHTO provisions)
COURSE PURPOSE: To introduce concepts in the analysis and design of reinforced concrete and steel bridges commonly encountered in the highway infrastructure. Basic concepts on the analysis and design of bridges using current West Pakistan Highway Code of Bridges (WPHCB), Indian Road Congress (IRC) Code and American Association of Highway Transportation Officials (AASHTO) specifications COURSE OUTCOMES AND OBJECTIVES: Upon completion of this course the student will be able to do the following: Ability to apply knowledge of mathematics, science, and engineering in the analysis and design common reinforced concrete and steel bridges. Ability to analyze bridges subjected to a variety of loading conditions. Ability to design bridges meeting existing IRC/WPHCB Specifications. Ability to design bridges meeting existing AASHTO Specifications
TOPICS COVERED: 1. Introduction (Week 1 -2) Brief History of Bridges – Week 1 Types and classification of Bridges – Week 1 Materials Used for Bridge Construction – Week 2 2. Concepts on Bridge Aesthetics (Week 3) 3. Introduction to Bridge Design /Specifications (Week-4) AASHTO 1996 specifications AASHTO LRFD specifications IRC specifications WPHCB specifications
Types of Loads on Bridges (Week -5) a. Gravity Loads i. Permanent Loads ii. Transient Loads Lane loads Vehicle loads Pedestrian loads b. Lateral Loads i. Fluid Loads ii. Earthquake Loads iii. Ice Loads c. Deformation -induced Loads i. Temperature ii. Creep and Shrinkage d. Collision Loads
Review of Influence Lines and Moment Distribution Method (Week 6) Influence lines Statically Determinate Beams Müller-Breslau Principle Statically Indeterminate Beams Moment Distribution Method
Distribution of Loads in: (Week 7-9) Superstructure to include Bridge decks and Bridge girders Substructure to include abutments, Bearings, piers and foundations
Analysis and Design of Bridges (Week 10-13) Solid Concrete slab Bridge (Week-10) Slab and Girder (T- Beam) Bridge (Week-11) Steel – Concrete Composite Bridge (Week-12) Precast-Prestressed Concrete Bridge (Week-13)
Modeling, Analysis and Design of Highway Bridges Using CSIBridge and STAADPRO Software (Week 14-16 Week)
DESIGN PROJECT:
The design project will consist of
the design of a bridge. The project
will be executed by teams of 3 to 4
students each. Each team will
select a particular type of bridge and
will analyze and design the main
structural components and verify the
results by using software along with
submission of Design calculations
and software INPUT/OUTPUT files. A
presentation of the final designs will
be required at the end of the
semester
1. Quiz 5% 2. Mid-Term Exam/OHTs 30% 3. Assignments 5% 4. Design Project 10% 5. Final exam (during finals week) 50%
TOTAL 100%
Grading Policy:
Grades will assign in the following manner:
What is a BRIDGE?
•Bridge is a structure which covers a gap
•Generally bridges carry a road or railway across a natural or artificial
obstacle such as, a river, canal or another railway or another road
•Bridge is a structure corresponding to the heaviest responsibility in carrying a
free flow of transport and is the most significant component of a transportation
system in case of communication over spacings/gaps for whatever reason
such as aquatic obstacles, valleys and gorges etc.
Bridge is the KEY ELEMENT
in a Transportation System
History
• Primitive Peoples: – Logs – Slabs of Rocks – Intertwined Vines or Ropes
• Roman Empire—First Great Bridge Builders – Timber Truss Bridges – Masonry Arch Bridges
• Europeans – Followed HRE Until Iron and Steel Use
• Nineteenth Century— – Modern Long Bridges – Moveable Bridges
Rock Bridges
Wadi Rum Rock Bridge
Rope Bridges
Log Bridges
LOG BRIDGE
Members of a Denver and Salt Lake Railroad Company (D&SL) survey crew pose on a log bridge over the Colorado River in Gore Canyon (Grand County), Colorado.
View of a settlement in (probably) Utah; shows a log bridge, a stream, and houses. People sit on a porch; a United States flag waves from a pole.
U.S. Army soldiers from the Ohio Engineers, building a small log bridge over a ditch, at Fort Sheridan, Illinois
LOG BRIDGE View of hot springs site enclosed by stone and wooden frame buildings, Hot Sulphur Springs, CO
Covered Bridges
COVERED BRIDGE
• Bridges. Old covered bridge, Jackson River, Va.
Structure of covered bridge. Wallingford, Vermont
Covered Bridge, Glen Canyon, Santa Cruz
County, CA
CONSTRUCTION
• Must carry own weight and weight of traffic – Must withstand force of high winds
– Must consider effects of contraction and/or
– Expansion due to temperature changes
– Most common materials • Wood—temporary
• Steel—for long, strong spans
• Reinforced concrete—attractive designs but difficult to work with on large bridges
• Prestressed concrete—stronger than reinforced, cheaper than steel
TYPES OF BRIDGES
•Fixed
•Moveable
•Other
Beam or Girder Bridges
FIXED
• Beam or Girder
– Two parallel beams w/ flooring supported by piers
– Span can be supported by trestle
– Used for hwy over/underpasses or small stream crossings
– Example—Covered Bridge
Cars on a suspension bridge over a river, possibly in Colorado.
enz_bridge.jpg
Millennium Bridge, London
ostruz.jpg www.prevodi-vertalingen.com/.../ ostruz.html
Truss Bridges
FIXED
• Truss
– Beam bridge strengthed by trusses (structural spts joined to form triangles with tie rods)
– Lighter than ordinary beam sections of equal length
– Useful for longer bridges
Timber Truss Bridge
Continuous Truss Bridges
View west of an iron truss bridge crossing the Colorado River on the Denver and Rio Grande Railroad Montrose line at Grand Junction, Colorado; people and horses are on a sand bar.
View of the bridge crossing the White River at Meeker, CO on the Mesa and Flag Creek road.
White Water Creek Bridge, Spanning White Water Creek, Bernard vicinity, Dubuque County, IA
Truss Bridge
View of a trestle bridge that crosses Arastra Gulch near Silverton (San Juan County), Colorado.
Jefferson Barracks Bridge
Location: Mississippi River, Jefferson Barracks, Missouri
Simple Truss Bridges
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FAI 24 Bridge Over the Ohio River Paducah, Kentucky
www.modjeski.com/projects/ servproj/paducah.htm
gcdranet.homelinux.com/davehonan/ bridges/il.html Cairo
Ohio River ferry and railroad bridge, Metropolis, IL
Arch Bridges
FIXED
• Arch
– One or more arches
– Masonry, reinforced concrete or steel
– Roadway on toop of arches or suspended by cables
– Spans can be longer than beam or truss
Aquaduct
Old stone bridge at Bull Run Battlefield. Manassas, Virginia.
Stone bridge in Rock Creek Park.
Stone bridge, Elizabeth Park, Hartford, Ct..
Old Stone Bridge, Boonton, N.J..
Stone Bridge at Bowling Green, Gallatin vicinity, Sumner County, TN
Segovia, Spain
Franklin Park, Ellicott Bridge, Emerald Necklace, Boston, MA
Pont du Gard
Arch bridge, Bellows Falls, Vt..
Bayonne Bridge, Spanning Kill Van Kull between Bayonne & Staten Is, Bayonne, Hudson County, NJ
Kill van Kull Bridge
[Hell Gate Bridge (New York Connecting RailroadBridge), New York].
[Hell Gate Bridge (New York Connecting RailroadBridge), New York].
Steel Arch Bridge, Niagara.
700 A.D. Asia
100 B.C. Romans
Natural Bridges
Clapper Bridge
Tree trunk Stone
The Arch Natural Cement
Roman Arch Bridge
History of Bridge Development
Great Stone Bridge in China
Low Bridge Shallow Arch
1300 A.D. Renaissance
Strength of Materials
Mathematical Theories
Development of Metal
First Cast-Iron Bridge
Coalbrookdale, England
1800 A.D.
History of Bridge Development
Britannia Tubular Bridge
1850 A.D.
Wrought Iron
Truss Bridges
Mechanics of Design
Suspension Bridges
Use of Steel for the suspending cables
1900 A.D.
1920 A.D.
Prestressed Concrete
Steel
2000 A.D.
Compression Tension
Basic Concepts
Span - the distance between two bridge supports, whether they are columns, towers or the wall of a canyon.
Compression - a force which acts to compress or shorten the thing it is acting on.
Tension - a force which acts to expand or lengthen the thing it is acting on.
Force - any action that tends to maintain or alter the position of a structure
Basic Concepts
Beam - a rigid, usually horizontal, structural element
Pier - a vertical supporting structure, such as a pillar
Cantilever - a projecting structure supported only at one end, like a shelf bracket or a diving board
Beam
Pier
Load - weight distribution throughout a structure
Basic Concepts
Truss - a rigid frame composed of short, straight pieces joined to form a series of triangles or other stable shapes
Stable - (adj.) ability to resist collapse and deformation; stability (n.) characteristic of a structure that is able to carry a realistic load without collapsing or deforming significantly
Deform - to change shape
To dissipate forces is to spread them out over a greater area, so that no one spot has to bear the brunt of the concentrated force.
To transfer forces is to move the forces from an area of weakness to an area of strength, an area designed to handle the forces.
Basic Concepts
Buckling is what happens when the force of compression overcomes an object's ability to handle compression. A mode of failure characterized generally by an unstable lateral deflection due to compressive action on the structural element involved.
Snapping is what happens when tension overcomes an object's ability to handle tension.
• Bridge Definition
• Bridge type
• Aesthetics in bridge design
• Factors considered in deciding bridge types
• Bridge components
It Controls the Capacity of the System
If the width of a bridge is insufficient to carry the number of
lanes required to handle the traffic volume, the bridge will be a
constriction to the flow of traffic. If the strength of a bridge is
deficient and unable to carry heavy trucks, load limits will be
posted and truck traffic will be rerouted.
The bridge controls both the volume and weight of the traffic
carried by the transportation system.
Highest Cost per Mile of the System
Bridges are expensive. The typical cost per mile of a bridge is many
times that of the approach roads to the bridge.`
Since, bridge is the key element in a transportation system, balance
must be achieved between handling future traffic volume and loads
and the cost of heavier and wider bridge structure.
If the Bridge Fails, the System Fails
The importance of a Bridge can be visualized by considering the comparison
between the two main components of a highway system i.e. a road and bridge itself.
EXAMPLE: Suppose in a road there occurs deterioration and ultimately a crack,
thus making a sort of inconvenience but it wont result in stopping of the flow of
traffic as traffic can pass or otherwise a bypass can be provided. The traffic no
doubt will pass with a slower speed but in case of a bridge its flow is completely
stopped incase of the failure of the bridge, that is the reason its often called “If the
bridge fails the structure fails” as the function of the structure could no longer be
served at all.
Classification of Bridges
Steel Concrete Wood Hybrid Stone/Brick
Pedestrian Highway Railroad
Short Medium Long
Slab Girder Truss Arch Suspension Cable-Stayed
Material
Usage
Span
Structural
Form
Structural Arrangement
Discussion on Classification According To
STRUCTURAL FORM
Distinctive Features of Girder Bridge
Distinctive Features of Arch Bridge
Distinctive Features of Truss Bridge
Distinctive Features of Suspension Bridge
Distinctive Features of Cable-Stayed
Bridges
Distinctive Features of Girder Bridges
•Widely constructed
•Usually used for Short and Medium spans
•Carry load in Shear and Flexural bending
•Efficient distribution of material is not possible
•Stability concerns limits the stresses and associated economy
•Economical and long lasting solution for vast majority of bridges
•Decks and girder usually act together to support the entire load in highway bridges
Distinctive Features of Arch Bridge
•Arch action reduces bending moments ( that is Tensile
Stresses )
•Economical as compared to equivalent straight simply supported Girder or Truss bridge
•Suitable site is a Valley with arch foundations on a DRY ROCK SLOPES
•Conventional curved arch rib has high Fabrication and Erection costs
•Erection easiest for Cantilever Arch and most difficult for Tied Arch
•Arch is predominantly a Compression member. Buckling must be worked to the detail so as to avoid reductions in allowable stresses.
•Classic arch form tends to favor Concrete as a
construction material
•Conventional arch has two moment resistant components : The deck and the Arch Rib.
•Near the crown of the arch and the region where Spandrel Columns are short, undesirable B.M. can occur. By using Pin ended columns it can be avoided
•Space beneath the arch is less and hence danger for
collision with the Rib, specially on a highway
•Curved shaped is always very pleasing and arch is the
most successful and beautiful structure
Distinctive Features of Arch Bridge
Distinctive Features of Truss Bridge
•The primary member forces are axial loads
•The open web system permits the use of a greater overall depth than for an equivalent solid web girder, hence reduced deflections and rigid structure
•Both these factors lead to Economy in material and a reduced dead weight
•These advantages are achieved at the expense of increased fabrication and maintenance costs
•Other bridge types have rendered the truss bridge types less likely to be used due to its high maintenance and fabrication costs.
•The truss is instead being used widely as the stiffening structure for the suspension bridges due to its acceptable aerodynamic behavior since the wind gusts can pass through the truss as is not with the case in girder, arch bridges.
Distinctive Features of Truss Bridge
•It’s a light weight structure it can be assembled member by member using
lifting equipment of small capacity.
•Rarely aesthetically pleasing complexity of member intersections if viewed
from oblique direction
•In large span structures poor aesthetic appearance of the truss bridge is
compensated with the large scale of the structure. For moderate spans its
best to provide a simple and regular structure
Distinctive Features of Suspension Bridge
•Major element is a flexible cable, shaped and supported in such a way that it
transfers the loads to the towers and anchorage
•This cable is commonly constructed from High Strength wires, either spun in situ or formed from component, spirally formed wire ropes. In either case allowable stresses are high of the order of 600 MPA
•The deck is hung from the cable by Hangers constructed of high strength ropes in tension
•As in the long spans the Self-weight of the structures becomes significant, so the use of high strength steel in tension, primarily in cables and secondarily in hangers leads to an economical structure.
•The economy of the cable must be balanced against the cost of the associated anchorage and towers. The anchorage cost may be high where foundation material is poor
Distinctive Features of Suspension Bridge
•The main cable is stiffened either by a pair of stiffening trusses or by a system of girders at deck level.
•This stiffening system serves to (a) control aerodynamic movements and (b) limit local angle changes in the deck. It may be unnecessary in cases where the dead load is great.
•The complete structure can be erected without intermediate staging from the ground
•The main structure is elegant and neatly expresses its function.
•It is the only alternative for spans over 600m, and it is generally regarded as competitive for spans down to 300m. However, shorter spans have also been built, including some very attractive pedestrian bridges
•The height of the main towers can be a disadvantage in some areas; for example, within the approach road for an AIRPORT
Distinctive Features of Cable-stayed Bridge
•The use of high strength cables in tension leads to economy in material, weight, and cost..
•As compared with the stiffened suspension bridge, the cables are straight rather than curved. As a result, the stiffness is greater
•The cables are anchored to the deck and cause compressive forces in the deck. For economical design, the deck must participate in carrying these forces
•All individual cables are shorter than full length of the superstructure. They are normally constructed of individual wire ropes, supplied complete with end fittings, prestretched and not spun.
•There is a great freedom of choice in selecting the structural arrangement
•Less efficient under Dead Load but more efficient in support Live Load. It is economical over 100-350m, some designer would extend the upper bound as high as 800m
Distinctive Features of Cable-stayed Bridge
•Aerodynamic stability has not been found to be a problem in structures erected to date
•When the cables are arranged in the single plane, at the longitudinal center line of the deck, the appearance of the structure is simplified and avoids cable intersections when the bridge is viewed obliquely
Discussion on Classification According To
SPAN
Small Span Bridges (up to 15m)
Medium Span Bridges (up to 50m)
Large Span Bridges (50-150m)
Extra Large ( Long ) Span Bridges (over
150m)
Small Span Bridges (up to 15m)
Culvert Bridge
Slab Bridges
T-Beam Bridge
Wood Beam Bridge
Pre-cast Concrete Box Beam Bridge
Pre-cast Concrete I-Beam Bridge
Rolled Steel Beam Bridge
Medium Span Bridges (up to
50m)
Pre-cast Concrete Box Beam & Pre-cast Concrete I-
Beam
Composite Rolled Steel Beam Bridge
Composite Steel Plate Girder Bridge
Cast-in-place RCC Box Girder Bridge
Cast-in-place Post-Tensioned Concrete Box Girder
Composite Steel Box Girder
Large Span Bridges (50 to 150m)
Composite Steel Plate Girder Bridge
Cast-in-place Post-Tensioned concrete Box
Girder
Post-Tensioned Concrete Segmental
Construction
Concrete Arch and Steel Arch
Extra Large (Long) Span Bridges
(Over 150m)
Cable Stayed Bridge
Suspension Bridge
Discussion on Classification According To
Structural Arrangement
•Main Structure Below the Deck Line
•Main Structure Above the Deck Line
•Main Structure coincides with the Deck Line
The classification of the bridge types can also be according to the location
of the main structure elements relative to the surface on which the user
travels, as follows:
Main Structure Below the Deck Line
Arch Bridge
Masonry Arch
Concrete Arch
Inclined Leg Frame Arch
Rigid Frame Arch
Truss-Arch Bridge Steel Truss-Arch
Steel Deck Truss
Main Structure Above the Deck Line
Suspension
Bridges
Cable Stayed Bridges
Through-Truss Bridge
Main Structure Coincides with the Deck Line
Girder Bridge
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)
CLASSIFICATION GIVEN BY R.S.RAKSHIT
YOUR TASK
PREPARE A COMPARISON SHEET
FACTORS CONSIDERED IN DECIDING
BRIDGE TYPE
•Geometric Conditions of the Site
•Subsurface Conditions of the Site
•Functional Requirements
•Aesthetics
•Economics and Ease of Maintenance
•Construction and Erection Consideration
•Legal Considerations
In general all the factors are related to economy, safety and aesthetics.
Geometric Conditions of the Site
•The type of bridge selected will always depend on the horizontal and vertical
alignment of the highway route and on the clearances above and below the
roadway
•For Example: if the roadway is on a curve, continuous box girders and slabs are a
good choice because they have a pleasing appearance, can readily be built on a
curve, and have a relatively high torsion resistance
•Relatively high bridges with larger spans over navigable waterways will require a
different bridge type than one with medium spans crossing a flood plain
•The site geometry will also dictate how traffic can be handled during construction,
which is an important safety issue and must be considered early in the planning
stage
Subsurface conditions of the soil
•The foundation soils at a site will determine whether abutments and piers can be
founded on spread footings, driven piles, or drilled shafts
•If the subsurface investigation indicates that creep settlement is going to be a
problem, the bridge type selected must be one that can accommodate differential
settlement over time
•Drainage conditions on the surface and below ground must be understood because
they influence the magnitude of earth pressures, movement of embankments, and
stability of cuts or fills
•For Example: An inclined leg frame bridge requires strong foundation material that
can resist both horizontal and vertical thrust. If it is not present, then another bridge
type is more appropriate.
•The potential for seismic activity at a site should also be a part of the
subsurface investigation. If seismicity is high, the substructure details
will change, affecting the superstructure loads as well
•All of these conditions influence the choice of substructure components
which in turn influence the choice of superstructure
Subsurface conditions of the soil
Functional Requirements •Bridge must function to carry present and future volumes of traffic.
•Decisions must be made on the number of lanes of traffic, inclusion of sidewalks
and/or bike paths, whether width of the bridge deck should include medians,
drainage of the surface waters, snow removal, and future wearing surface.
•For Example: In the case of stream and flood plain crossings, the bridge must
continue to function during periods of high water and not impose a severe
constriction or obstruction to the flow of water or debris.
•Satisfaction of these functional requirements will recommend some bridge types
over others.
•For Example: if future widening and replacement of bridge decks is a concern,
multiple girder bridge types are preferred over concrete segmental box girders.
Economic and ease of maintenance
•The initial cost and maintenance cost over the life of the bridge govern when
comparing the economics of different bridge types.
•A general rule is that the bridge with the minimum number of spans, fewest deck
joints, and widest spacing of girders will be the most economical.
•For Example: (1) By reducing the number of spans in a bridge layout by one span,
the construction cost of one pier is eliminated. (2) Deck joints are a high
maintenance cost item, so minimizing their number will reduce the life cycle cost of
the bridge. (3) When using the empirical design of bridge decks in the AASHTO
(1994) LRFD Specifications, the same reinforcement is used for deck spans up to
4.1m. Therefore, there is little cost increase in the deck for wider spacing for girders
and fewer girders means less cost although at the “expense” of deeper sections.
Economic and ease of maintenance
•Generally, concrete structures require less maintenance than steel structure. The
cost and hazard of maintenance painting of steel structures should be considered
in type selection studies.
•One effective way to reduce the overall project cost is to allow contractors to
propose an alternative design or designs.
Construction and Erection Considerations
•The length of the time required to construct a bridge is important and will vary
with the bridge type.
•Generally, larger the prefabricated or pre-cast members shorter the
construction time. However, the larger the members, the more difficult they
are to transport and lift into place.
•The availability of skilled labor and specified materials will also influence the
choice of a particular bridge type.
•For Example: if there are no pre-cast plants for pre-stressed girders within
easy transport but there is a steel fabrication plant nearby that could make the
steel structure more economical.
•The only way to determine which bridge type is more economical is to bid
alternative designs.
Legal Considerations
•Regulations are beyond the control of an engineer, but they are real and must
be considered.
Examples of certain regulations are as follows:
•Permits Over Navigable Waterways
•National Environmental policy Act
•Department of Transportation Act
•National historic preservation Act
•Clean Air Act
•Noise Control Act
Legal Considerations
•Fish and Wildlife Coordination Act
•The Endangered Species Act
•Water Bank Act
•Wild and Scenic Rivers Act
•In addition to the environmental laws and acts defining national policies,
local and regional politics are also of concern
Discussion on Bridge Components
•Common bridge components
•Components of a Girder bridge (Beam Bridge)
•Components of a Suspension Bridge
General Bridge Components
Bridge Bearings: These are supports on a bridge pier, which carry
the weight of the bridge and control the movements at the bridge
supports, including the temperature expansion and contraction. They
may be metal rockers, rollers or slides or merely rubber or laminated
rubber ( Rubber with steel plates glued into it).
Bridge Dampers & Isolators: Bridge dampers are devices that absorb
energy generated by earthquake waves and lateral load
Bridge Pier: A wide column or short wall of masonry or plain or
reinforced concrete for carrying loads as a support for a bridge, but in
any case it is founded on firm ground below the river mud
General Bridge Components
Bridge Cap: The highest part of a bridge pier on which the bridge
bearings or rollers are seated. It may be of stone, brick or plain or
reinforced concrete.
Bridge Deck: The load bearing floor of a bridge which carries and
spreads the loads to the main beams. It is either of reinforced concrete.,
pre-stressed concrete, welded steel etc.
Abutment: A support of an arch or bridge etc which may carry a
horizontal force as well as weight.
Expansion Joints : These are provided to accommodate the translations
due to possible shrinkage and expansions due to temperature changes.
Components of a Girder bridge (Beam Bridge)
Components of a Suspension Bridge
• Anchor Block: Just looking at the figure we can compare it as a dead
man having no function of its own other than its weight.
• Suspension girder: It is a girder built into a suspension bridge to
distribute the loads uniformly among the suspenders and thus to reduce
the local deflections under concentrated loads.
• Suspenders: a vertical hanger in a suspension bridge by which the road
is carried on the cables
• Tower: Towers transfers compression forces to the foundation through
piers.
• Saddles: A steel block over the towers of a suspension bridge which
acts as a bearing surface for the cable passing over it.
• Cables: Members that take tensile forces and transmit it through
saddles to towers and rest of the forces to anchorage block.
BRIDGE SPECIFICATIONS • Meaning of bridge specifications.
• Need of bridge specifications.
History
Development
Lack of specification and usage of proper codes and safety factors -------reason of failure of a structure (bridge)
Use and check of safety factors case study of wasserwork bridge for the check of present working capacity.
Assignment: Main reason of failure for some bridge/bridges
BRIDGE SPECIFICATION • Basically the word specification stands in general for a
collection of work description upon which there is a mutual agreement of the most experienced group of people based upon their practical and theoretical knowledge
• Bridge specification:
Applying the above mentioned definition, context to bridge makes it self explanatory.
Bridge Cap and
Damper
ARCH BRIDGE
ARCH BRIDGE
ARCH BRIDGE
ARCH BRIDGE
GIRDER BRIDGE
GIRDER BRIDGE
GIRDER BRIDGE
GIRDER BRIDGE
Is it possible to design
an “Instant Bridge?”
Almost! There are many
ways to put a bridge
together quickly with
precast concrete
products.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
The speed and
variety of precast
prestressed
products and
methods give
designers many
options. Consider
these advantages of
an
all-precast bridge…
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Fast construction benefits owner
agencies by reducing the duration of
the work zone. Fast construction
reduces traffic handling costs and
accident exposure risks. There’s less
inconvenience to the traveling public,
fewer delays, and fewer motorist
complaints. According to a report by
the Texas Transportation Institute,
costs incurred by drivers passing
through a work zone (along with
engineering costs) can be $10,000 to
$20,000 per day. A recent Federal
report indicates user costs of $50,000
per day for work zones in urban
areas.
Benefits to Owner Agencies:
Reduction in the duration of
work zones
Reduced traffic handling costs
Reduced accident exposure risks
Less inconvenience to the
traveling public
Fewer motorist complaints
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Contractors benefit from
reduced exposure to traffic
hazards. More work can be
accomplished in less time,
with fewer weather delays.
Costs are lower for forms,
skilled field labor, scaffolding
and shoring, and cranes.
Benefits to Contractors:
Reduced exposure to hazards
More work -- less time
Fewer weather delays
Lower costs
Less skilled labor
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
After foundations have been
completed, scheduling can
be controlled by a single
contractor working with a
familiar material.
Scheduling Control
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Precast concrete structural
elements should always be
plant produced under
carefully controlled
conditions…by plants that
are Certified by PCI.
Plant-produced Elements
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
… so all structural elements
benefit from the excellent
quality and corrosion
resistance of prestressed
concrete.
Quality and Corrosion Resistance
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Fully-cured precast concrete
structural elements can be
stockpiled in advance of
need…
Stockpiled in Advance
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
…and can be scheduled for
“just-in-time” delivery and
erection…
Immediate Delivery and Erection
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
There’s no curing time
required at the jobsite, as
with cast-in-place concrete.
Bridge piers can be erected
in a day, and beams can
follow immediately.
No Curing Time
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
The following photos
illustrate the many products
and construction methods
that enable very rapid
project completion. In
addition to the often-used
superstructure elements of
girders and deck slabs,
substructure components
such as these piers can also
be precast.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Precast concrete piles are
quite popular in much of the
country. They come in
different sizes and shapes,
ranging from 10-inch square
piles to 66-inch diameter
hollow cylinder piles.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Pile caps also can be precast
concrete, reducing exposure,
forming and curing in
the field.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Piers can be made of precast
concrete pieces quickly
assembled in
the field.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Abutments can also be made
of precast.
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
The Sucker Creek Bridge in
Hague, New York, consists of
precast concrete box beams
supported on precast
concrete abutments
assembled into a jointless,
rigid frame.
Sucker Creek Bridge in Hague
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
In San Juan, Puerto Rico, the
totally precast concrete
Baldorioty de Castro Avenue
bridges were built in record-
setting time, attractively, and
economically.
Puerto Rico
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK MAIN
Each of four bridges, ranging
in length from 700 to 900
feet, was erected in about
24 hours. This was well
within the owner’s
construction allowance of 72
hours per bridge, a condition
established to minimize
disruption to one of the
city’s highly traveled
corridors.
Puerto Rico -
A totally
precast bridge
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
In addition to speed, the
bridges also met the city’s
budgetary needs. The four
box-beam bridges were
constructed for $2 million
less than the next lowest bid
for another material.
Puerto Rico
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Totally precast bridge systems
may be the only viable solution
in harsh field conditions.
The Confederation Bridge
connecting Canada’s Prince
Edward Island to mainland New
Brunswick is such
an example.
The bridge spanned the eight-
mile-wide Northumberland
strait, which experiences severe
winters and is covered with ice
floes for five months of the
year.
Confederation Bridge
New Brunswick, Canada
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Even in such harsh
conditions, precast concrete
was able to meet the
owner’s requirements of a
100-year service life,
a 3½-year construction
period, and attractiveness.
Confederation Bridge
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
It just makes economic sense
to evaluate conversion of
cast-in-place to precast
concrete. This was done for
the Edison Bridge in Florida.
Precast piers and beams
were spliced to produce tall
pier bents.
Edison Bridge
Florida
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
The state of Texas has
constructed several bridges
with segmental precast
concrete piers. The
attractive piers and pier caps
are hollow members. Some
are made of high-
performance concrete. Such
segments may be match-
cast, similar to segmental
box girder bridges, or
separated by a thin mortar
bed, much like giant
masonry units.
Texas - Precast Piers
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
In Houston, the Louetta
Road Overpass utilized
precast concrete match-cast
piers, as well as precast,
prestressed U-beams and
stay-in-place deck panels.
Louetta Road Bridge
Texas
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Another famous bridge is the
Sunshine Skyway Bridge over
Tampa Bay in Florida. The
piles, piers and pier caps
were constructed of precast
concrete elements
connected together with
post-tensioning threadbars.
Sunshine Skyway Bridge
Florida
TOTALLY PRECAST BRIDGES -- CASE STUDIES
FORWARD BACK
Truss Bridges Truss Basics – Overview
A metal truss bridge is a bridge whose main structure
comes from a triangular framework of structural steel or
iron.
Iron and Steel Truss Basics – Forms of Metal
Due to their variety of designs, there is a system that is
used to classify metal truss bridges by design.
Truss Basics
If the trusses run beside the deck, with no cross bracing above the deck, it is called a pony truss bridge.
If cross-bracing is present above the deck of the bridge, then the bridge is referred to as a “through truss.”
Pony Truss
Through Truss
Truss Basics – Pony / Through
Truss Basics
Trusses may run under the deck: these are called simply Deck truss bridges.
Truss Basics – Deck
Deck Truss
The different parts of a truss bridge are all named. Some of the parts:
Top / Upper Chord Vertical (Member)
Diagonal (Member)
Bottom / Lower Chord
Portal Bracing
Sway Bracing
Lateral Bracing
Floor beam Connections
End Post
Each space between vertical members and end posts is one panel. This bridge has six panels.
Truss Bridge Parts Truss Bridge Parts
Hip Vertical (Only the verticals that meet the top of the end post)
The chords and members of a truss bridge experience
strain in the form of tension (stretching apart) and
compression (squeezing together). Engineers often
picked different types of materials and designs for the
different parts of a bridge based on these forces. An
example is shown above.
Truss Bridge Forces Truss Bridge Forces
Tension
Compression
Truss Bridge Connections Truss
Connections
The pieces of the framework of a truss bridge are held
together by connections. Most connections on historic
bridges are either riveted or pinned.
Pinned Connections Truss Connections - Pinned
Pinned connections can be identified by the bolt-like
object called a pin going through the loops of the
members. They tend to show up on bridges from the first
half of the truss bridge era.
Pin
Riveted Connections Truss Connections - Riveted
Riveted connections are identified by a “gusset plate”
which diagonals and vertical members are riveted to,
and no pin is present. These connections tend to show
up in the second half of the truss bridge era.
Truss Configurations
Pratt
Overview: One of the two most common configurations, it tends
to occupy the earlier half of the truss bridge era, but was used
throughout. Originally developed by Thomas and Caleb Pratt in
1844.
Appearance: Diagonal members angle toward the center and
bottom of bridge.
Truss Configurations
Pratt – Additional Notes
The Pratt may have additional diagonal members,
sometimes of a smaller size, that do not follow the
standard pattern to form an “X” shape on panels toward
the center.
Truss Configurations
Whipple
Overview: The Whipple truss is also known as the double-
intersection Pratt truss. It was patented by Squire Whipple in 1847
as a stronger version of the Pratt truss.
Appearance: Similar to the Pratt truss, but the diagonals pass
through one vertical member before reaching the bottom chord.
They tend to show up on longer spans built in the first half of the
truss era, and with pinned connections.
Truss Configurations
Baltimore
Overview: The Baltimore railroad designed a truss configuration
that eventually found use on both railroads and highways. It is a
Pratt truss with additional members added for additional strength.
Appearance: Characterized by a Pratt configuration with extra
smaller members branching off of the diagonals.
Truss Configurations
Parker Overview: Charles
H. Parker modified
the Pratt design to
create what became
known as the Parker
truss configuration.
This design allowed
one to use less
materials to get the
a similar load
capacity. The
downside was the
more complex
design.
Appearance: Characterized by an arch-shaped (polygonal) top
chord, with diagonals that follow the Pratt configuration.
Truss Configurations
Pennsylvania
Overview: Sometimes called the Petit truss. Designed by the
Pennsylvania railroad, this configuration combines the
engineering ideas behind the Baltimore with those of the Parker or
Camelback.
Appearance: Features an arch-shaped (polygonal) top chord with
a diagonal arrangement like the Baltimore.
Truss Configurations
Warren
Appearance: Alternating diagonal members form a repeating “V”
shape. A true Warren does not have vertical members.
Overview: The other most common truss configuration, this
design tended to be used in the second half of the truss bridge
era, and with riveted connections. Originally developed in 1848 by
James Warren and Willoughby Monzoni.
Truss Configurations
Warren: With Verticals
Most Warren truss bridges do in fact feature vertical members.
They may be referenced simply as “warren with verticals” truss
bridges. Vertical members may occur at each connection, or every
other connection.
Truss Configurations
Double-Intersection Warren
Overview: Often called simply the Double Warren, this is an
uncommon truss configuration. Bridges with this configuration
often have riveted connections. Appearance: Looks like two Warren trusses offset and
superimposed on each other, forming a repeating “X” shape.
Truss Configurations
Lenticular
Overview: One of the rarest bridge designs in the country.
Patented by the Berlin Iron Bridge Company of East Berlin, CT
Appearance: Both the top chord and bottom chord have an
arched appearance, forming a distinctive oval or eye-like shape.
Truss bridge
Truss Bridge
Truss Bridge
Truss Bridge
Truss Bridge
Truss Bridge
Curved Cable Stayed Bridge
This is an innovative curved cable stayed bridge. It is designed to provide maximum support around turns where a whole new bridge would need to be built.
Waldo Hancock Bridge
This the is new Waldo Hancock Bridge. It replaced the old one in the background due to corrosion. This is one of the only suspension bridges in the country that has an observation tower in the top. I have been up in the tower and would strongly suggest seeing it for yourself.
Suspension Bridge Design
What you need to know
A suspension bridge is a type of bridge where the deck is hung below suspension cables on vertical suspenders. Suspension bridges are efficient at holding up a large amount of wait over a long span. A suspension bridge usually has two towers that hold up the horizontal cables. From these main horizontal cables hang vertical cables that are attached to the deck of the bridge. A suspension bridge must with stand forces of tension on its cables and large amounts of compression on its towers.
Famous Suspension Bridges
The Golden Gate Bridge in San Francisco
The Akashi-Kaikyo bridge in Japan The longest bridge in the world at 6529 feet long.
Verrazano-Narrows Bridge
The Verrazano-Narrows Bridge is the longest suspension bridge in the U.S. It is 4,260 feet long. It is a double decked bridge in New York City.
Suspension Bridge
Suspension Bridge
Suspension Bridge
Movable Bridges
• They span waterways
• Closed bridge to carry traffic
•Open to allow marine traffic to travel
under
• Usually powered by electric motors
•In the past they were powered by
steam engines
• There are three main types:
1.Bascule
2.Vertical lift
3. Swing
Bascule Bridge or Drawbridge
•Used for short distances
•Have two movable spans
the rise upward, opening
in the middle
•When open the weight is
supported by the
stationary section of the
bridge
Vertical-lift Bridge
• Used for longer distances • Straight bridge, held between two towers • Lifted by steel ropes, attached to counterweights -as the counterweights go down the bridge goes
up and vise-versa. • Operate in an elevator like fashion
Swing Bridges
• Mounted on a central pier
• The central pier allows the bridge to rotate to the side
• Uncommonly used because the central pier is located in the area where boats like to travel
http://www.brokk.com/images/jpg/sando.jpg
Sydney, Australia
www.bardaglea.org.uk/.../ bridge-types-arch.html
Arches can also be set above the deck as on the Sydney harbour bridge in Australia. This allows much more space beneath for ships to pass under.
Blue Water Bridge
Blue Water Bridges are a major international crossing over the St. Clair river at the southern end of Lake Huron
Eads Bridge, St. Louis
Port Mann Bridge, Coquitlam-Surrey BC This graceful steel arch, once the third-longest of its kind in the world, carries the Trans-Canada highway across the Fraser River. In 2002 its capacity was increased with the addition of an eastbound high occupancy vehicle (HOV) lane, bringing the total to five
www.balsabridge.com/ bridge-van.htm
Cantilever Bridges
FIXED
• Cantilever
• Double-ended brackets supporting a center span
• Shore end of each cantilever firmly anchored
• Center supported by pier
Quebec Bridge
Quebec Bridge
Quebec Bridge
Quebec Bridge
Quebec
Bridge
Quebec Bridge
Quebec Bridge
On June 15, 1907 an inspecting engineer noted that two girders of the anchor was misaligned by a quarter of an inch. Cooper called this a "not serious" problem. In the inspection report in August, 1907, it was noted that the girders had moved out alignment a bit more and "appeared bent". Although this condition was a bit more concerning, the work continued.
Scotland's Firth of Forth
A period museum photo shows cranes atop the massive structure. The bridge was constructed from 1882-1890, 2.5 KM (1.5 miles) across Scotland's Firth
of Forth. Note reflection of photographer from glass frame. http://www.pre-engineering.com/resources/forth/forthbridge.htm
Lewis and Clark Bridge (Longview-Rainier Bridge) across the Columbia River.
[Queensboro Bridge, Roosevelt Island, New York, N.Y.].
Astoria bridge
Suspension Bridges
FIXED
• Suspension
– Roadway hangs from vertical cables supported by overhead cables strung between two or more towers
– Longest spans
– Costly
– Difficult to design
– Highly susceptible to winds and swaying
– Cables can be up to three feet in diameter
Tanana River suspension bridge.
http://tapseis.anl.gov/guide/photo/Tanana_Bridge.html
Tsing Ma Bridge, Hong Kong
Akashi-Kaikyo Bridge, Japan
Brooklyn Bridge
The 3rd Carquinez Strait Bridge will replace the original bridge that was built in 1927.
Ambassador Bridge
Ambassador Bridge
Golden Gate Bridge
Golden Gate Structures
When it opened in 1964, the Verrazano Narrows Bridge was the
world's longest suspension span. Today, its length is surpassed
only by the Humber Bridge in England.
Verrazano
Tacoma Narrows Bridge collapsing, Tacoma, Washington, 1940 On the morning of November 7, 1940, the Tacoma Narrows Bridge twisted violently in 42-mile-per-hour winds and collapsed into the cold waters of the Puget Sound. The disaster -- which luckily took no human lives -- shook the engineering community and forever changed the way bridges were built around the world. Roadway of Tacoma Narrows Bridge twisting violently in a windstorm, Tacoma, Washington, 1940
Cable-Stayed Bridges
FIXED
• Cable-Stayed
• Suspended by cables that run directly down to roadway from central towers
• Less costly than suspension
• Quickly constructable
• Spans must be limited in length
Sunshine Skyway Bridge, St. Petersburg and Bradenton, Florida
Sunshine Skyway Bridge, St. Petersburg and Bradenton, Florida
Clark Bridge in Alton, IL
Clark Bridge in Alton, IL
Clark Bridge in Alton, IL
Dames Port Florida
Dames Port Florida
Dames Port Florida
Swing Bridges
MOVEABLE
• Swing
• Central span turned 90 degrees on pivot pier placed in middle of waterway
• Double swing possible
Catalog Advertisement
Moveable Bridge
BRIDGE ACROSS SHATT-AL-ARAB, IRAQ
Detail of south truss showing truss configuration and connections HAER, MASS,2-WIND,1-3
Detail of south truss showing truss configuration and connections HAER, MASS,2-WIND,1-3
Coleman Bridge, Spanning Phelps Brook, on Windsor Bush Road, at th, Windsor, Berkshire County, MA
Bascule Bridges
MOVEABLE
• Bascule
– One or two sections not supported by piers
– Balanced on one end by counterweights
– Section jackknifes up to allow passage of ships
– Most common type of highway drawbridge
View of an elevated train crossing the Van Buren Street Railroad Bridge which spanned the Chicago River from the Loop to the Near West Side community area in Chicago, Illinois.
View of a bascule bridge over the Chicago River in Chicago, Illinois.
Haarlem old lifting bridge.
Lifting bridges are moveable bridges which enable boats to pass. They vary from simple wooden designs such as many seen in the Netherlands to large steel structures which carry heavy roads such as the bascule bridge in Docklands.
Erie Street Bridge, a bascule bridge, with the two leaves in raised position
Sault Ste. Marie International Bridge
Erie Avenue Bridge Newberry Bridge
Vertical Lift Bridges
MOVEABLE
• Vertical Lift
– Central span extends between two towers
– Balanced by counterweights
– Variation of this type is bridge over Shatt-al-arab River in Iraq—Roadway sinks into water to allow ships to pass over it
Vertical lift Baltimore (Pratt) through-truss railroad bridge
Cape Cod Canal Railroad Bridge Buzzards Bay, Massachusetts
Leamington Lift Bridge, Scotland
Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Isl, Staten Island, Richmond County, NY
Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Isl, Staten Island, Richmond County, NY
GUIABA RIVER AT PORTO ALEGRE, BRAZIL
The vertical lift bridge that carries US-41 across the Portage Canal.
Aerial bridge, Duluth, Minn..
Aerial bridge, Duluth, Minn..
Aerial bridge, Duluth, Minn..
Bailey Bridges
OTHER
• Bailey
– Small truss bridge made in sections
– Assembled on shore
– Pushed out from shore to cover span
– Transportable to new sites
Bailey
Tank destroyer advances along a mountain road, Italy
Pontoon Bridges
OTHER
• Pontoon
– Floats on water
– Can be disassembled and moved to new site
– Supported by pontoons or barges
The U.S. Army's Sava River bridge is taken apart at nightfall and put together in the
morning
View of James River Pontoon Bridge, from south side, above Jones' Landing.
Pontoon bridges, North Anna, constructed by the 50th N.Y.V. Engineers, below railroad bridge, where a portion of the 2nd Corps, under Gen. Hancock crossed 23rd May, 1864
Broadway Landing, Va. Pontoon bridge across the Appomattox
Evergreen Floating Bridge
Evergreen Bridge.
The official name of the bridge is the Governor Albert D. Rosellini Bridge at
Evergreen Point, after a popular former governor who was in office when the
bridge opened.
Combined Bridges
[Stony Brook glen, Shawmut Bridge, Dansville, N.Y.].
Knie_bridge
Lake_Pontchartrain_Causeway-vi.jpg
Lake_Pontchartrain_Causeway-vi.jpg
Old Alton Bridge
Name that Bridge
Give the type for each.