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COMPETITION RULES |
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COMPETITION RULES |
DESCRIPTION:
The competition
will consist of the construction and testing of a model timber bridge on the
home site of each team.
ELIGIBILITY:
The competition is
open to all student chapters of American Society of Civil Engineers and Forest
Products Society in the United States and Canada. Joint and multiple entries from one school will be accepted.
COMPETITION SPECIFICATIONS:
Each contestant
(team) will be required to design, build and test a bridge constructed from
wood structural members. The wood used
in this project must be from a commercially available species. Be sure to check out our list of more
than two dozen links to wood products design data, technical values,
specifications, treatment information, supplies, etc. on the main page for
the Competition.
WOOD TREATMENT:
All wood members must be treated to AWPA standards for
"above ground use". See www.awpa.com
for details on ordering publications or go to Western Wood Preservers
Institute site, click on "retentions" at bottom of menu to left,
then select preservative type for standards tables. NOTE: Since all the
most common procedures for meeting AWPA standards require pre-treatment in a
pressurized environment to attain adequate retention levels, the treatment type
and process should be part of the bridge design process, rather than a
post-treatment alternative. There
are plenty of safe treatment materials available, so student safety should be
considered, but not prohibitive. The life expectancy of all metal fasteners,
cables, plates and other non-wood components should be considered for all
bridges expected to have a “life after competition”, however, this will not be
a competition requirement.
DESIGN CRITERIA:
Design Span: 4.0 meters from center line to center line
of supports. The maximum length of an
individual piece in any member shall not exceed 3.0 meters. There is no length limitation on built-up
and laminated members prepared by contestant, provided that the individual
pieces, including plywood, used in making the member do not exceed the
specified maximum length. Maximum width
of supporting base plates is 60 mm.
There is no length constraint on cables, straps, rods or other
tensioning devices.
Horizontal Clearance: 1.3m inside curb to inside curb.
Vertical Clearance: 2.5 meters from deck surface (overhead
clearance).
Depth of Understructure: Maximum of 500 mm at center-span and 1000
mm at support base measured from top surface of deck to lowest point of support
structure.
Test Load: 20 kN for 1 hour. (See test
setup for location of loading blocks.)
Load Application and Deflection
Measurements: The load will
be applied in 4 equal increments of 5 kN each, with the full load of 20 kN
being achieved in not less than 5 minutes or more than 20 minutes. Deflection readings will be recorded at each
5kN load increment. Then, four
deflection readings shall be recorded at 15-minute intervals during the 1-hour
full-load duration.
Maximum Vertical Bridge Deflection: Maximum allowed bridge deflection is 10.0 mm as recorded at midspan of the
longitudinal beam receiving the greatest loading. Subtraction from deflection due to compression of supports will
not be allowed. If two or more
longitudinal beams are predicted to receive equal loading, select only one to
monitor, or monitor all such beams and submit average deflection (contestant's
choice).
Maximum Vertical Net Deck Deflection: Maximum allowed net deck deflection is deck
span divided by 100, with deck span being measured as the shortest side of the
largest “deck panel” formed by 2 longitudinal members and 2 transverse members,
if applicable. "Deck panel"
is defined as any area of clear-span deck bordered (i.e. defined) by the 2
nearest longitudinal bridge support members and the 2 nearest transverse
support members, if applicable. In
other words, deck span is the distance between points monitored by the 2 gauges
at points 3 and 4 below. However, note that deck span is actually measured from
inside structural member to inside structural member. If largest deck panel is a cantilevered section of the bridge,
then one side is defined by the curb.
Gross deck
deflection shall be measured under the centroid of the loading point placed
where the deck is calculated to experience maximum deflection under full
loading if the 4-point load is moved anywhere on the deck. This point should be
the same as the center of the largest “deck panel” described above. The selected loading point must be at the
deck’s weakest point. It must be halfway between any transverse members such as
floor beams, deck stiffeners, cross-bracings, diaphragms, etc. that make
contact with the deck’s underneath surface. It must also be halfway between any
adjacent longitudinal support members.
Net deck deflection
shall be determined by subtracting the average of the deflections recorded in
the 2 bridge structural members forming the longer side of the largest bridge
“deck panel” as recorded at midpoint of the longest sides of the “deck panel”
and as measured by gauges at points 3 and 4 below. See “Test Setup” sketch for
details on placement of the 4 loading points, size of bearing plates, etc.
Note that more than
one loading setup may be required to properly measure both bridge deflection
and deck deflection at their weakest points, i.e. at points of expected maximum
deflection. Some designs may, however, allow for one loading setup to monitor
both defections. If needed, the 4-point loading setup may be moved as a unit only
transversely to monitor Maximum Vertical Bridge Deflection, but it may be moved
as a unit both transversely and longitudinally to monitor Maximum Vertical Deck
Deflection, thus placing any one of the
four loading points over the center of the largest “deck panel”.
Drawings must clearly document location of
load points. Failure of drawings to clearly document location of below 4 gauge
points and the location of the 4 loading points (at one or both setups as
applicable) will result in disqualification.
Disqualification may also occur if photos “c” and “d” below (See
Documentation) contradict drawings. Location
of all monitoring gauges for each loading set-up must also be shown as follows:
1.
Midpoint of
longitudinal beam predicted to experience maximum loading. Resulting deflection
is Maximum Vertical Bridge Deflection.
2.
Centroid of
largest “deck panel” as described in Maximum Vertical Net Deck Deflection above.
Resulting deflection is Maximum Gross Deck Deflection.
3.
At midpoint of
one of the longest sides of the selected “deck panel”.
4.
At midpoint of
the other longest side of the above “deck panel”.
Note that distance between point 3 and point
4 is Deck Span. Net Deck Deflection is deflection measured at point 2
subtracted by the average of the two deflections measured at points 3 and
4.
Bridge Deck: The bridge deck does not have to be wood,
but note 25% by weight nonwood restriction on total bridge weight. Any material can be used as long as it is
designed to effectively transfer loads at all locations on its surface to the
support structure, is not an open grid, can be treated to withstand
weather-related deterioration, can withstand repetitive traffic loading and
wear, and is capable of supporting the complete 4-load combination moved
anywhere on the deck surface. In other
words, it must work in real-life application!
The maximum length per piece limit (3.0 meters) still applies to deck
materials. The deck must be uniform in
thickness, material, etc. throughout (i.e. “beefed up” deck in the area of the
load point selected for gauging deck deflection will cause disqualification).
Prestressing: Prestressing will be allowed provided it is
done 48 hours before testing.
Bridge Weight: Bridge must be weighed before
testing and must include all bridge parts forming a part of the bridge as a
structural system. Note that total
nonwood components cannot exceed 25% of total bridge weight.
Curb: The curb does not need to resist a force but must be connected to the
bridge. The curb may be a part of arch
or truss members or a longitudinal support beam. Curb material must meet same
requirements as Deck except for load bearing, but can be a load-bearing member.
It must have a minimum size of 40 mm x 80 mm (2 x 4)
DOCUMENTATION:
Contestants will be
required to submit by email:
1.
Digital
Photographs: Transmit in .gif, .jpg, .tif or .bmp format. No
.pdf files can be received. Photos must
be no larger than 640 x 480 pixels in size; and if possible, with 300 dots
per inch resolution or better. Transmit to southwest@msrcd.org
as attachments to one email, with each file titled showing school name
abbreviated and photo labeled per rules.
For example, “MSU side view finish.gif”. Color prints will be accepted only if contestant does not have
access to digital camera. Following photos are required (no more, no less!):
a. Four photos of bridge construction featuring
key structural components of bridge, such as deck, longitudinal supports,
transverse beams, connectors, etc. as applicable. No more than 4, please! (msu deck.jpg)
b. One photo of weighing bridge (msu weigh.jpg)
c.
One end view
of loading setup (msu end loaded.jpg)
d. One side view of loading setup (msu side
loaded.jpg)
e. One photo of each deflection monitor at full
loading, with identification sign indicating, "deck", "beam
left", "beam right", “bridge”. (msu monitor deck.jpg, msu
monitor beaml.jpg, msu monitor beamr.jpg, msu monitor bridge,jpg)
f.
One side view
of finished bridge from above plane of bridge deck (msu side finish above.jpg)
g. One end view of finished bridge from below
plane of bridge deck (msu side finish below.jpg)
h.
One trimetric
view of bridge showing both side and end. (msu trimetric.jpg)
i.
One group
picture of design team either on bridge or with bridge in foreground from a
trimetric view (msu group.jpg)
NOTE: In pictures
"h" and "i" above, try to avoid background and foreground
clutter. Adding a sign with school name is advisable for future publicity.
2.
Digital
Drawings:
·
Must be adequate to inform judges of bridge
dimensions, including size and spacing of all longitudinal and transverse
components,
·
Must show 3 views (plan or overhead, side or
elevation, and end) or show 1 trimetric view (preferred!) if all
required details can be shown,
·
Must show location of the selected load point
monitored for deck deflection, the location of the 4-point load setup for
bridge deflection, and the location of all gauges monitoring structural member
deflections for determining both deck and bridge deflection.
·
Must be transmitted as e-mail attachments in either .jpeg (preferred) or
.gif at size of approximately 640 x 480
pixels. No autocad or .pdf files
can be received.
·
NOTE: Be sure lettering is large enough to read
easily on computer screen!
Following materials
should be mailed to reach
Competition coordinators by deadline:
1.
Drawings: Mail
an 8 1/2-inch x 11-inch hard copy of bridge drawing(s) entered online. See
Drawings requirement above. This item is mandatory.
2.
Certification
and Entry Form (print from website). This
item is mandatory.
3.
Any
photographs required in "a" through "i" above or a computer
disk containing the digital photos. No zip disks, please! Neither of these are
required if the required digital photos were successfully transmitted in the
format and size stated, but is recommended
4.
A complete
printout of the Online Entry. This item
is optional, but recommended
REPORT:
A technical report
must be submitted online (via Internet) using templates provided and will
include:
1.
Abstracts:
Using maximum of 500 words, explain the bridge design concept and explain what
was done to optimize stiffness while attempting to minimize weight of the
structure.
2.
Table of all
recorded test results of deflection measurements.
3.
An itemized
materials list showing weight of non-wood components and total weight of
bridge. The total weight of non-wood
material must be less than 25% of the total weight of the bridge. Glue is non-wood.
4.
A short
summary (max. 500 words) describing the bridge and its behavior under load.
5.
Short
description of major bridge components (10 words or less per component).
6.
Description of
preservative treatment used and why it was selected.
7.
Project
impact. Was the experience beneficial to design team? What end-use did the
bridge have after testing?
JUDGING:
A panel of three
independent judges not affiliated with any contestant institutions will select
the winners. Entries that do not meet
all rules and performance criteria will be disqualified for consideration for
Performance and Best Design Awards but will be eligible to compete for Special
Awards. No single entry shall be
eligible to receive more than three awards.
AWARDS:
1.
Weyerhaeuser
Best Overall Design (1st-$750, 2nd-$500, 3rd-$250). This award is intended to reward intellectual effort, regardless
of how the design meets the performance-related standards. Judged using following points:
·
Design is a
configuration of structural elements that can be optimized through normal
engineering methods (20%)
·
Design makes
efficient use of structural materials (20%)
·
Design is
based on structural concepts that have broad applications (20%)
·
Design shows
intellectual efforts (20%)
·
Judges'
Review/Report (20%) (adequate documentation, clarity, neatness, content,
abstract, photos, video)
2.
Performance
Awards
·
Maximum Bridge
Deflection 30%
·
Total Bridge
Weight 10%
·
Percent
Nonwood (total bridge) 10%
·
Practical 20%
·
Innovative –
Structural Design 15%
·
Innovative –
Materials 15%
·
Net Deck
Deflection 30%
·
Total Bridge
Weight 10%
·
Percent
Nonwood (total bridge) 10%
·
Practical 20%
·
Innovative –
Structural Design 15%
·
Innovative –
Materials 15%
3.
Special
Awards: (Each category: 1st-$300, 2nd-$200, 3rd-$100)
·
Most Practical
Design - Design that can be practical to implement in real-life design
and construction; low-tech and easy to construct (low materials and labor
costs).
·
Most Aesthetic
Design
·
Most
Innovative Design (in the use of new and non-traditional materials and/or
construction methods)
4.
Participation
Awards: The first 20 schools to submit a complete entry will each receive a
$150 Participation Award to help offset some of their materials expenses, if
the entry meets all rules requirements.
DEADLINES:
Deadline for online
entry (www.msrcd.org/b-entry.htm) and receipt of mailed material is April 9,
2004. Mail to SW Mississippi RC&D,
1395 Johnny Johnson Dr., Suite E, Brookhaven, MS 39601. Enclose following
information with mailed material:
College or University
Student Chapter name, address, phone,
fax, e-mail. Be sure address is a
permanent department mailing address; will be used for mailing awards check.
Faculty advisor
Contact person.
All materials
received by RC&D will become the property of RC&D.
NOTE: This deadline may be inconvenient for
schools on the quarter system wishing to incorporate participation into spring
or summer coursework. However, these may compete in the 2005 Competition by
following 2003 rules posted on this website. 2005 Competition will follow 2003
rules; likewise 2004 rules will become 2006 rules. The award amounts may change
from year to year.
RESULTS:
Winners will be
announced online by May 4, 2004. In
addition, the full entries of all participants will be released online and
available for all contestants as well as any Internet user to review. Each can learn from the successes and
failures of others! The results will also be publicized through various
publications.
ADDITIONAL INFORMATION:
Submit questions by
e-mail to southwest@msrcd.org, or contact Bennie Hutchins, SW MS RC&D,
phone 601-833-5539, fax 601-835-0054.
Check Q&A/Updates regularly for valuable competition updates, rules
clarifications, etc.
