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CONSTRUCTION

TECHNOLOGY &

maintenance

CEM 417

Stages for construction

WEEK 3

1. Building

2. Retaining walls, Drainage

3. Road, Highway, Bridges

4. Airports, Offshore/Marine structure

ROADS,

HIGHWAYS &

BRIDGES

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WEEK 3

At the end of week 3 lectures, student will be

able to :

- Identify the different types of roads,

highways and bridges and their respective

functions. (CO1; CO3)

HIGHWAY

Development Process

and Functional

Classification

flash.lakeheadu.ca/.../Highway%20Design%20-

%20Class%20notes%202%20-

%20Functional%20classification.ppt

OVERVIEW OF THE

HIGHWAY DEVELOPMENT PROCESS

http://www.fhwa.dot.gov/environment/flex/ch01.htm

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HIGHWAY DEVELOPMENT PROCESS

Highway design is only one element of the overall development process

Five stages of highway development process: planning, project development, final design, right-of-way, and construction

Different activities with overlap in terms of coordination

Flexibility available for highway design during the detailed design phase is limited by decisions on early stages

http://www.fhwa.dot.gov/environment/flex/ch01.htm

PLANNING

Initial definition of the need for any highway or bridge improvement project takes place in this phase

Problems identified fall into these categories:

Existing physical structure needs major repair/replacement

Existing or projected future travel demands exceed available capacity, and access to transportation and mobility need to be increased (capacity).

The route is experiencing an inordinate number of safety and accident problems that can only be resolved through physical, geometric changes (safety).

Developmental pressures along the route make a reexamination of the number, location, and physical design of access points necessary (access).

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PLANNING (CONTD.)

Once problem is identified, it is important that all parties agree that the problem exists and that it should be fixed

Consider potential impacts of project: How will the proposed transportation improvement

affect the general physical character of the area surrounding the project?

Does the area to be affected have unique historic or scenic characteristics?

What are the safety, capacity, and cost concerns of the community?

Answers on this phase

FACTORS IN PLANNING

http://www.fhwa.dot.gov/environment/flex/ch01.htm

PROJECT DEVELOPMENT

Environmental analysis intensifies

Includes a description of the location and major design features of the recommended project

Try to avoid, minimize and mitigate environmental impacts

Basic steps: Refinement of purpose and need

Development of a range of alternatives (including the "no-build" and traffic management system)

Evaluation of alternatives and their impact on the natural and built environments

Development of appropriate mitigation

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PROJECT DEVELOPMENT (CONTD.)

Assess area

Consider context and physical location

Data collection effort

Identify constraints

Consider factors and select preferred

alternative

http://www.fhwa.dot.gov/environment/flex/ch01.htm

FINAL DESIGN

After a preferred alternative is selected and the project description agreed on upon as stated in the environmental document, the final design occurs

The product of this phase is a complete set of plans, specifications, and estimates (PS&Es) of required quantities of materials ready for the solicitation of construction bids and subsequent construction

Depending on the scale and complexity, this phase may take from a few months to several years

FINAL DESIGN (CONTD.)

Need to employ imagination, ingenuity and

flexibility

Be aware of commitment of previous phases

Ability of making minor changes to original

concept

Design considerations

Developing a concept

Considering scale

Detailing the design

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RIGHT-OF-WAY, CONSTRUCTION

AND MAINTENANCE

During the right-of-way acquisition and

construction phases, minor adjustments in

the design may be necessary

Construction may be simple or complex and

may require a few months to several years

Maintenance is very important to keep the

character of the road

Functional

Classification

FUNCTIONAL CLASSIFICATION

Is the process by which streets and

highways are grouped into classes, or

systems, according to the character of

traffic service that they are intended to

provide

Streets and highways classification

Orderly grouping roads based on service

Assist in geometric design features

In accordance with operational needs

Establishes hierarchy of roads

Efficient and safe if road serve their purpose

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FUNCTIONAL CLASSIFICATION

(CONTD.)

Assessment of operating conditions

Comparison between actual and intended

purpose

Chance to sort data based on type of road

Collision data not yet available

Three functional classifications:

arterials

Collector

local roads

ROADWAY FUNCTIONAL

CLASSES

Determined by

characteristics:

function

access density

traffic demands

trip length

expected speed

http://www.fhwa.dot.gov/environment/flex/ch01.htm

ROADWAY FUNCTIONAL CLASSES

(CONTD.)

Arterial: highest level of service, high

mobility, low access, long trips, fast speeds

Collector: less highly developed level of

service, lower speed for shorter trips,

collects traffic from local roads and

connecting them with arterials

Local: all roads not defined as arterials or

collectors, provides access to land with

littler or not through traffic, low speed

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SERVICE FUNCTIONSOURCE: TAC GEOMETRIC DESIGN GUIDE FOR CANADIAN

ROADS

FUNCTIONAL CLASSIFICATION

IN THE DESIGN PROCESS

The first step in the design process is to define the

function that the facility is to serve.

The level of service required to fulfill this function

provides the basis for design speed and geometric

criteria within the range of values available to the

designer

Functional classification decisions are made before the

design phase, but there is flexibility in the major

controlling factor of design speed

DESIGN CLASSIFICATION SYSTEM

Source: TAC Geometric Design Guide for Canadian Roads

Classification system (differences in) Traffic and land service

Design features

Operational needs (adjacent land use)

For all areas in Canada

Rural (R) Urban (U)Lane

Local (L) Local (L)

Collector (C) Collector (C)

Arterial (A) Arterial (A)

Expressway (E)

Freeway (F) Freeway (F)

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DESIGN CLASSIFICATION (CONTD.)

Ten primary divisions

Design subdivisions Divided (D) or undivided (U)

Design speed (value)

Example (See Table 1.3.2.1, next slide) RAD (90)

UCU (80)

Comments

Number of classes: 63

Design speed increases from local to freeways

All locals street are undivided

All freeways are divided

RURAL DESIGN CLASSIFICATIONSOURCE: TAC GEOMETRIC DESIGN GUIDE FOR CANADIAN

ROADS

FACTORS CONSIDERED IN

CLASSIFICATION

Adjacent Land Use:

Urban vs. rural classification

Service Function:

Access to land. Ex: local

Service to traffic. Ex: freeways

both

Traffic Volume:

Freeways: high volume

Collectors and locals: low volume

Flow Characteristics: Freeways: uninterrupted facility

Locals; interrupted facility

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FACTORS CONSIDERED IN

CLASSIFICATION (CONTD.)

Running Speed: Generally increase from locals to collectors to

arterials to freeways

Vehicle Type: Proportion of passenger cars, buses, large trucks

Connections: Normal for roads to connect to the same

classification or one higher or one lower

See Table 1.3.3.1

For Characteristics of Rural Roads See Table 1.3.4.1

For Characteristics of Urban Roads See Table 1.3.4.2

ROAD CONNECTIONS

COMMENTS

Comments: Rural and urban roads are the same in terms of service

function, and land service

Volumes are higher on urban roads than on rural roads

Design speeds on urban roads are lower than in rural roads

Vehicles types are different, especially for local streets

Government agency responsible for each type of road: Municipal government -urban: local, collectors

Provincial government –rural - freeways

Similar roads have similar designs, construction, maintenance and operation Similar roads: similar costs

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BRIDGES

Development Process

and Functional

Classification

HTTP://WWW.BUZZLE.COM/ARTICLES/TYPES-OF-

BRIDGES.HTML

Top 20 Most Popular Bridges in the World

Other than the above given names, here are some

more names of the most famous bridges of the

world. Chengyang Bridge, China

Akashi-Kaikyo Bridge, Japan

Alcántara Bridge, Spain

Millau Bridge, France

Chapel Bridge, Switzerland

Galata Bridge, Turkey

Tsing Ma Bridge, Hong Kong

Banpo Bridge, South Korea

Magdeburg Water Bridge,

Germany

Howrah Bridge, India

Kintai Bridge, Japan

Chain Bridge, Hungary

Ponte Vecchio, Italy

Pont des Arts, France

Bosphorus Bridge, Turkey

Charles Bridge, Czech Republic

Rialto Bridge, Italy

Jacques Cartier Bridge, Canada

Stari Most, Bosnia and

Herzegovina

Great Belt Bridge, Denmark

Bridge is not a construction but it is a concept,

the concept of crossing over large spans of land or

huge masses of water. The idea behind a bridge is

to connect two far-off points eventually reducing

the distance between them. Apart from this

poetic aspect of ‘bridges’, there is a technical

aspect to them that classifies bridges on the basis

of the techniques of their construction

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Beam Bridge: A beam bridge was derived from the log

bridge. It is built from shallow steel beams, box girders

and concrete. Highway overpasses, flyovers or

walkways are often beam bridges. A horizontal beam

supported at its ends comprises the structure of a beam

bridge. The construction of a beam bridge is the

simplest of all the types of bridges.

Truss Bridge: A truss bridge is built by connecting

straight elements with the help of pin joints. Owing to

the abundance of wood in the United States, truss

bridges of the olden times used timbers for compression

and iron rods for bearing tension. Truss bridges came

to be commonly constructed from the 1870s to the

1930s. Deck truss railroad bridge that extends over the

Erie Canal is one of the many famous truss bridges.

Arch Bridge: Going by its name, it is arch-shaped

and has supports at both its ends. The weight of an

arch-shaped bridge is forced into the supports at either

end. The Mycenaean Arkadiko Bridge in Greece of

1300 BC is the oldest existing arch-shaped bridge.

Etruscans and the ancient Greeks were aware of

arches since long. But the Romans were foremost in

discovering the use of arches in the construction of

bridges. Arch bridges have now evolved into

compression arch suspended-deck bridge enabling the

use of light and strongly tensile materials in their

construction.

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Suspension Bridge: A bridge falling under this

category is suspended from cables. The suspension

cables are anchored at each end of the bridge. The load

that the bridge bears converts into the tension in the

cables. These cables stretch beyond the pillars up to

the dock-level supports further to the anchors in the

ground. The Golden Gate Bridge of USA, Tsing Ma

Bridge of China and the Humber Bridge of England

are some of the famous suspension bridges.

Cable-stayed Bridge: Structured similar to the

suspension bridges, the difference lies in the amount of

cable used. Less cable is required and consequently,

the towers holding the cables are shorter. Two

variants of cable-stayed bridges exist. In the harp

design, cables are attached to multiple points of the

tower thus making them parallel. In the fan variant of

design, all the cables connect to the tower or pass over

it. Cable Bridge boasts of being the first cable-stayed

bridge of USA. Centennial Bridge is another well-

known cable-stayed bridge.

Cantilever bridge: Cantilevers are the structures

that project along the X-axis in space. They are

supported only on one end. Bridges intended to carry

lesser traffic may use simple beams while those aimed

at handling larger traffic make use of trusses or box

girders. The 1800 feet Quebec Bridge of Canada and

the San Francisco-Oakland Bay Bridge that is 1400

feet long are some examples of the cantilever bridges.

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Truss Bridge Types

Truss is a structure composed of triangular units which

consists of straight beams connected at the joints called

nodes. The application of this principle and their

improvisation further led to the invention and design of

various types of truss bridges around the world. These

are some truss bridge types with examples:

Howe Truss BridgeThis is named after its inventor William Howe, and was designed for the use of

timber as diagonal compressions and iron as vertical tensions. Howe truss was later

improvised to use steel for its construction and became a forerunner of iron bridges.

These truss bridge types are popular as railroad bridges, and a well preserved

example is the Comstock Bridge over the Salmon river, Colchester.

Allan Truss BridgeThis was designed by Percy Allan, hence it was named as Allan Truss. Hampden

Bridge in Wagga Wagga, New South Wales, Australia, is one of the most famous

bridges and an example of Allan Truss Bridge. It is the first of this type and

constructed with wood and ironbark for strength. This is the simplest among the

other truss bridges, economical due to the use of less material and easier to repair.

Truss Arch BridgeThis type of truss bridge combines the design of truss and arch bridges, in which

the trusses are fitted within the arch. A famous example of this type is the Iron

Bridge across the river Severn, Shropshire, England.

Bollman Truss BridgeNamed after its inventor Wendell Bollman, this type of truss bridge is built only using metals,

mostly wrought iron and cast iron. Most of the railroad bridges around the world are built by

adopting this design due to the ease of assembly and its durability. Though common after its

invention, only one bridge of this type is available today. The oldest and most historic, the

Bollman Truss Rail Road Bridge in Savage, Maryland, is an example of revolutionary truss

bridge design in engineering history.

Pratt Truss BridgeIt is exactly the opposite of Howe truss bridge in structure. Here, the diagonals are in tension

and the vertical elements are under compression, both sloping towards the center in a V-shape.

Earlier Pratt truss bridges were made of timber and iron truss, but later it was made of iron

only. It has many variations, due to the modifications made on this design, to make it lighter,

but was originally designed by Thomas and Celeb Pratt. An example of these truss bridge types

is the Schell Bridge in Northfield, Massachusetts.

Bowstring Arch Truce BridgeThe father of tied arch bridge is considered to be Squire Whipple. This involves

complicated engineering among the various truss bridge types, where the tension of

the top chord is supported by the bottom chord, rather than being supported by the

ground foundation. Due to this quality, tied arch bridges are usually built in areas

of unstable soil. An example of this type is the Torikai Big Bridge over the Yado

river, Osaka, Japan.

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Cantilever BridgeCantilever bridges are named after its use of cantilevers and involve one of

the most complex designs among different truss bridges. For supporting

heavy load, cantilever bridges either use steel trusses or concrete box

girders. For long bridges, steel truss cantilevers are used, which gives it

strength and can be easily constructed. The Quebec Bridge in Quebec,

Canada, is not only listed as one of the famous bridges of the world, but is

also the longest cantilever bridge around.

Bailey BridgeThis type of truss bridge was originally designed by Donald Bailey for use

by military engineering units. These are portable bridges and are small

enough for easy transportation, handling, installation and reuse. They are

modular bridges, and unlike previous portable bridges used by the

military, these do not require complicated equipments while assembling,

and are very cost-effective.

Comstock Bridge

Over Salmon River north of Route 16

Colchester-East Hampton

Covered timber truss

Length: 2 spans, 110' overall, 80‘ Maximum

span length

Built in 1873

The Howe Truss Bridge (designed by William Howe ) was patented in 1840. The advantages of the Howe Truss Bridge to the railroad companies of the era were that it was easy to prefabricate offsite and to ship by rail.

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Truss Arch

Bridge

Bollman

Truss

Bridge

Pratt Truss Bridge

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Bowstring

Arch Truss

Bridge

Cantilever Bridge

Bailey Bridge