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25 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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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

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


O
VERVIEW

OF

THE


H
IGHWAY

D
EVELOPMENT

P
ROCESS

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

H
IGHWAY

D
EVELOPMENT

P
ROCESS


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

P
LANNING


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).

P
LANNING

(
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

F
ACTORS

IN

P
LANNING

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

P
ROJECT

D
EVELOPMENT


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

P
ROJECT

D
EVELOPMENT

(
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

F
INAL

D
ESIGN


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

F
INAL

D
ESIGN

(
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

R
IGHT
-
OF
-
W
AY
, C
ONSTRUCTION


AND

M
AINTENANCE


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

F
UNCTIONAL

C
LASSIFICATION


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

F
UNCTIONAL

C
LASSIFICATION

(
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

R
OADWAY

F
UNCTIONAL

C
LASSES

(
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


S
ERVICE

F
UNCTION

S
OURCE
: TAC G
EOMETRIC

D
ESIGN

G
UIDE

FOR

C
ANADIAN

R
OADS

F
UNCTIONAL

C
LASSIFICATION


IN

THE

D
ESIGN

P
ROCESS


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

D
ESIGN

C
LASSIFICATION

S
YSTEM


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)

D
ESIGN

C
LASSIFICATION

(
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

R
URAL

D
ESIGN

C
LASSIFICATION

S
OURCE
: TAC G
EOMETRIC

D
ESIGN

G
UIDE

FOR

C
ANADIAN

R
OADS


F
ACTORS

CONSIDERED

IN

C
LASSIFICATION


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

F
ACTORS

CONSIDERED

IN

C
LASSIFICATION

(
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

R
OAD

C
ONNECTIONS

C
OMMENTS


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

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


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.


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.



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 Bridge

This 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 Bridge

This 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 Bridge

This 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 Bridge

Named 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 Bridge

It 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 Bridge

The 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.



Cantilever Bridge

Cantilever 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 Bridge

This 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.


Truss Arch
Bridge

Bollman
Truss
Bridge

Pratt Truss Bridge

Bowstring
Arch Truss
Bridge

Cantilever Bridge

Bailey Bridge