Building structure report

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Building Structures [ARC 2523]
PROJECT 1: FETTUCCINE TRUSS BRIDGE
A4 Documentation
Name (Student ID): Eunice Chan Yu Ming 0315729
Foo Wei Min 0321577
Koh Kar Yi 0320567
Teo Chen Yi 0320618
Lecturer: Pn. Norita Johar

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Table of Content
1.0 Introduction
1.1 Objectives
1.2 Project requirement
1.3 Report overview
1.4 Timeline
2.0 Methodology
2.1 Precedent study
2.2 Materials testing and Equipment preparation
2.3 Model making and design development
2.4 Structural analysis
2.5 Bridge efficiency calculation
3.0 Precedent Study
3.1 Background history
3.2 Joints and connections
3.3 Structure
4.0 Material and Equipment
4.1 Material
4.2 Equipment
5.0 Structural Analysis and Design Solution
5.1 Compression and tension
5.2 Member profile and orientation
5.3 Joint
6.0 Final bridge
6.1 Amendments and final bridge design
6.2 Final model making
6.3 Final bridge testing
6.6 Calculation and diagram
7.0 Conclusion
8.0 Appendix
9.0 Reference

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1.0 Introduction
1.1 Objectives
The objectives of project 1 are as following:
 To develop understanding of tension and compressive strength of construction
materials.
 To develop understanding of force distribution in a truss
 To design a perfect truss bridge which fulfils the following two main criteria which
are efficiency and minimal usage of material.
In the end of the project, we will be able to evaluate, explore and improve attributes of
construction materials. By applying understanding of load distribution in a truss, we will
evaluate and identify tension and compression members in a truss structure. Different
arrangement of members in a truss structure will be explored according to
understanding and analysis of load distribution.
1.2 ProjectRequirements
Project 1 is divided into 2 parts – individual and group.
Individual: Each member is required to solve a case of a truss system and determine
the most effective and efficient truss arrangement for the load system.
Group: In a group of 4-5, we are required to design and construct a fettuccine bridge of
350mm clear span and maximum weight of 70g.
1.3 Report Overview
This project requires a group of 4 to build a perfect truss bridge made of fettuccine in 7
weeks. The beginning of this project started with exploration of different truss design
through precedent studies. Analysis on strength, profile and joints, as well as the
reasons of failure are recorded in every test. A series of testing are carried out and
modification on design is discussed to achieve higher efficiency. Lastly, we are to solve
the calculation assigned for individual case studies and all data are to be recorded in
this project.

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1.4 Timeline
Date Event
2/4  Testing of compressive strength of different brands of fettuccine Prego,
San Remo original and San Remo spinach.
9/4  Testing of tensile strength of different brands fettuccine
 Testing of different profile and orientation for chosen brand
 Design and testing of first truss bridge (Warren).
17/4  Research of different bridge design
 Design and testing of second truss bridge (Pratt).
20/4  Compare and analyse Warren and Pratt truss bridge.
 Identify and analyse breaking points.
 Decision on truss design and profile.
30/4  Design and testing of third bridge (Warren).
 Decision of type of fettuccine.
1/5  Design and testing of forth bridge (A).
6/5  Design and testing of fifth bridge (A).
7/5  Design and testing of sixth bridge (A).

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2.0 Methodology
2.1 Precedent studies
Exploration on various design of perfect truss through precedent studies allow us to pick
up the strengths and limitation of existing bridges. Modifications are made to increase
the efficiency.
2.2 MaterialTesting and EquipmentPreparation
Equipment such as weighing scale, water bottle, pail, and s hook are prepared and set
up for testing to be carried out. A series of testing are done to figure out the following:
 Best fettuccine brand to be used based on the material strength
 Strongest profile and orientation to resist compression force
 Strongest profile and orientation to resist tension force
 Suitable joints and connection to resist different force
 The best adhesive in connecting the members
2.3 ModelMaking and Design Development
After the analysis on single members is done, we progress further on making the whole
bridge. Different perfect truss are tested to determine the strongest structure. Strengths
and weakness of different trusses are taken into consideration for best bridge design.
2.4 StructuralAnalysis
Structure model is analysed through calculation to show understanding of truss and
load transfer. The factors causing failure of bridge structure is analysed and discussed
for improvement.
2.4 Bridge efficiency Calculation
The efficiency of the bridge is calculated using this formula:
Efficiency, E = Maximum Load
Weight of Bridge

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3.0 Precedent Study
3.1 Backgroundhistory
The “Waddell A” Truss Bridge, currently located in English Landing Park, Parkville,
designed by engineer John Alexander Low Waddell in 1898. It was previously built as a
railroad bridge in Linn Branch Creek, and now crosses Rush Creek carrying a
pedestrian path between a day-use recreational and two isolated ball fields. In 1980, the
bridge was disassembled and was kept by the U.S Army Corps of Engineer for 7 years.
Nevertheless, the bridge retains its integrity of design as drawn by John Low Waddell; it
was then reassembled with the same standards as originally specified by the designer.
This bridge is approximately 40 feet high and 100 feet long. It rests on two concrete
abutments and is composed of pin-connected riveted units. Waddell's "A" truss was
developed to meet the need for a consistent, easily erected, short-span railroad bridge
and is regarded as a transitional phase in bridge design.
Figure 1: Photograph showing Waddell A truss bridge in Parkville, Missouri.

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3.2 Joint and Connections
Figure 2: Photograph showing members in Waddell A Truss Bridge.
Figure 3: Diagram showing joints between each member.

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Figure 4: Photographs showing pinned (left) and gusset plate (right) connections.
Figure 5: Diagram (left) and photograph (right) showing cross bracing of Waddell A truss bridge.

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Figure 6: Photographs showing cross bracing under the bridge (left) and bottom chord lateral cross
bracing (right).
Figure 7: Photograph showing gusset joint found at the top chord.

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Figure 8: Photograph (left) and diagram (right) showing pinned joint.
Figure 9: Diagram showing detailed drawing of pinned joint connection.

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3.3 Structure
The Waddell “A” Truss Bridge is a triangular shaped steel through-truss bridge; it is
single span and length around 100ft with the deck width of 16ft and 40 meters high.
Each truss has four panels, the distance between are around 5.2 meters.
Figure 10: Diagram showing force distribution of bridge under load pressure.
The A shaped top post that are connected by top bracing are usually in compression.
Therefore, X bracing that sandwiches between the two trusses were to provide sideway
stability.
The compression members are shop riveted built up sections, made out of angles,
plates and channels, conversely, tension members are made of pairs of eye-bars. The
bottom chord is divided into four sections, 25ft by 17ft, sway-braced by angle braces
and supporting a pair of girder stringers, angle braced.
Figure 11: Photograph showing dataplate of the bridge.

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4.0 Material and Equipment
4.1 Materials
4.1.1 Fettuccine
Three types of fettuccine are measured/tested for the following characteristics:
 Weight of one 25cm of fettuccine, W (g)
10 strips of 25cm fettuccine are weighed to calculate the average weight for a
single fettuccine.
 Cross-sectional area in ascendant order, A (small to large)
 Strength ranking. *Data tabulated in 5.1.1 Compression (Page 15)
Type of Fettuccine W (g) A Strength ranking
Prego
1.3 1 3
San Remo original
1.5 2 2
San Remo spinach
1.7
3 1

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4.1.2 Adhesive
Three types of adhesive are compared to achieve the most effective result:
Types of Adhesive Advantages Disadvantages
UHU Glue
 Easy to use
 Slow solidify time
 Joints flexible after
dry
V Tech 502 Super Glue
 Easy to use
 Strong and firm
connection
 High efficiency
 Fast solidify time
 Makes fettuccine
brittle
 Expand and
bending might
occur
Hot Glue
 Strong adhesion
 Long solidify time
 Creates bulky
finishing
 Hard to control
 Carries contain
weight
Conclusion:
Based on the comparison made, V Tech 502 super glue performs the best on the
Fettuccine Bridge as firm and strong connections are required to withstand load. Also, it
does not affect much on the weight of the bridge compared to the other two. Therefore,
V Tech 502 super glue is selected.

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4.2 Equipment
Different equipment are used throughout the project
Types of Equipment Function
Weighing scale
 Measure the weight of Fettuccine bridge and
the load.
Craft knife
 To cut the fettuccine precisely.
Sand paper
 To sand the edges of fettuccine to ease
connections.
Pail
 Act as load together with the water added in.
S hook
 To hook the load to the fettuccine bridge.
strings
 To tie the pail to the fettuccine bridge.

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5.0 Structural Analysis and Design Solution
5.1.0 Compressionand tension
5.1.1 Compression
A test is carried out to find the relationship between the
length of fettuccine and its compressive strength. The
compressive strength is represented by the maximum
weight a single fettuccine can withstand before it buckles.
Manipulated variable: Length of a single fettuccine, L (cm)
Responding variable: Maximum weight withstand
before buckling, W (g)
Controlled variable: Type of Fettuccine (San Remo
Spinach and San Remo Original)
Result:
L (cm) W (g)
Prego S.R Original S.R Spinach
5 448 601 947
7 280 301 394
9 154 177 222
11 126 133 182
13 85 92 127
15 69 73 76
17 63 64 75
19 51 48 56
21 34 41 35
Figure 12: Photograph showing
compression test fettuccine.

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23 24 35 34
25 23 30 34
Conclusion:
 The longer the fettuccine is, the more weight it can withstand before buckling.
There are two effects of compression on a structural member - crushing and buckling.
Members below a certain length will experience crushing while the members exceeding
the length will experience buckling. However, force required to cause crushing is much
larger in comparison with buckling. Therefore, there is a limitation that compressive test
showing crushing effect cannot be tested using this method.
 The compressive strength of the types of fettuccine in descendent order: San
Remo Spinach, San Remo Original, Prego.
Factors of compressive strength:
It is found that compressive strength of a structural member can be affected by others
factors besides its length. Below shows all factors that affect compressive strength:
 Length
 Type of material used
 Width and thickness of cross-section
 Profile of cross-section.
5.1.2 Tension
Unlike compression, the length and profile of cross-section of a structural member are
not factors of tensile strength. Below shows the factors of tensile strength:
 Type of material used
 Width and thickness of cross-section

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5.1.3 Conclusion
The factors affecting compressive and tensile strength can be summarized as below:
Affecting Factors Compression Tension
Length of material ✓ ✘
Type of material used ✓ ✓
Width and thickness of cross-
section
✓ ✓
Profile of cross-section ✓ ✘
As tensile strength is not affected by length while compressive strength is, there is no
way to decide the length of fettuccine used for testing to compare its compressive and
tensile strength. Therefore, it is not possible to test if fettuccine is stronger in
compression or tension by the amount of force it can withstand.
However, unlike compressive strength, tensile strength is only affected by two factors.
This makes fettuccine more efficient in withstanding tension than compression.
5.2 Member profile and orientation
A bending test is carried out to find the relationship
between member profile/orientation and its strength.
The strength of fettuccine is represented by the
maximum weight it can carry before rupture.
Manipulated variable: Fettuccine profile
Responding variable: Maximum weight withstand
before rupture, W (g)
Controlled variable: Type of fettuccine (S.R Spinach),
Clear span (175mm)
Figure 13: Photograph
showing bending test for
different profile and
orientation of member.

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Result:
Fettuccine profile (cross section) W (g)
185
264
469
476
684
1085
1276
1365
1523
637
1770
1267
2624
1795

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Conclusion:
As weight is a factor to be considered in this project, strength of each profile is
compared by the number of layers used in the profile. It is assumed that the number of
layers is directly proportional to the weight of the member, with the amount of glue used
for connection as a neglected factor.
Below shows the strength of profile made of different numbers of layer in descendent
order:
Number of layers Strength in descendent order
1 ,
2 ,
3
, , ,
4 ,
5 ,
7
,
Therefore, for compression, it is more efficient to use vertical and I profiles instead of
horizontal and H profiles.
For tension, as it is not affected by cross sectional profile, 3 layer laminated profile
maybe more efficient than I as the surface in contact for connection between layers is
larger.

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5.3 Joints
Joint A
The end posts are pushing against each other under compression. Figure 1.1 shows the
first attempt, with its connection beten the top chords and the middle chord relatively
weaker. Use of gusset could give more rigidity. However, total weight would increase.
Figure 1.2a and 1.2b show improvements made to allow stronger adhesion of top chord
with middle chord made of ‘I beam’ profile.
Joint B

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To achieve clear span of 350mm, we have made the bottom chord 40cm long, thus
impossible to avoid using end joint. 2cm gussets are added in exposed side to get the
benefits of a lap joint, making the joint as strong as possible.
Joint C
Lap joint is applied in the core where the point load is applied. This joint helps members
in compression to resist bending and maximises the surface area in contact between
bottom chord and middle core.
Joint D
The struts used in connecting the top chords are to resist moment. By applying to real
life examples, the end posts are connected this way. Only three struts were used initially
and were added to six struts (three on each half of the chord) to allow a more efficient
load distribution of compressive force.

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6.0 Final Bridge
6.1.0 Amendments and final bridge design
6.1.1 Amendments
Bridge 1: Pratt Truss Bridge
Weight of the bridge: 60g
Maximum load withstand: 2570g
Failure: Joint
Structure analysis and design solution:
1. Joint connections
Fettuccine is not cut properly. Uneven surface at the tip reduces the surface area
in contact with adhesive hence lowering the strength of the joint. Sand paper can
be used.
2. Bottom chords
Bending is observed at the bottom chord of bridge. Bottom chord member profile
(3 layer laminated) is not strong enough to withstand the load.
3. Height and angle
Height of the bridge not only increases the amount of fettuccine used (hence
increasing its weight), it affects the angle of diagonal member to be more than
the optimum angle of 45°.

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Bridge 2: Warren Truss Bridge
Failure: Top chord
1. Top chord
Bending is observed at the top chord. Top chord member profile (3 layer
laminated) is not strong enough to withstand the load.
2. Angle
Angle of the diagonal member is not kept at 45° optimum angle.
3. Height
Bridge is made too high increasing its weight.
4. Diagonal member
Orientation can be changed to increase its strength.

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Bridge 3: Warren Truss Bridge
Failure: Top chord
1. Deflection
Major deflection is observed. It is believed to be the misalignment of two truss by
struts. The two trusses are not perfectly parallel to each other.
2. Top chord
Bridge fails at the top chord although 2 layers I-beam is used. Straight top chord
will be replaced by stronger ‘A’ end post.

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Bridge 4: “A” Truss Bridge (Spinach)
Failure: Strut Insufficient of strut that pushes against each other when it is being
compressed
1. Strut
Insufficient strut fails when excessive compressive force pushes trusses against
each other.
2. Diagonal member
Only 2 out of 6 diagonal members are of 45° optimum angle. Another 2 diagonal
members will be changed to 45° optimum angle by changing its orientation.
3. Middle chord
3 layers laminated middle chord will be changed to single layer I-beam.

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Bridge 5: “A” Truss Bridge
Failure: Bottom chord
1. Bottom chord
Bottom chord fails at splice when two fettuccines are connected. An additional
piece of fettuccine will act as gusset plate to strengthen the joint.
2. Connection
I-beam middle chord and I-beam end post are not securely joined together.
3. Truss members
Truss members will be reduced to reduce weight.
4. End post
End post will be made taller for better load distribution.

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Bridge 6: “A” Truss Bridge
Failure: Bottom chord
1. Bottom chord
Bottom chord fails near to the contact point with the support (table). Piece of
fettuccine will be added at the side of the I-beam bottom chord near the support.
2. Strut
More strut will be added to hold the truss together more securely.

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6.1.2 Final bridge design
1. End post
 Increased angle for stronger structure.
 Single I-beam
2. Diagonal member
- 45° optimum angle
- Single layer

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3. Bottom chord
- 1-2-2 layers I-beam is used for bottom chord to resist bending moment.
- Additional pieces of fettuccine are added at splice and near to support where
are prone to snapping.
4. Middle chord
 Single layer I-beam.

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5. Vertical member
- Single layer
6. Middle core where point load is applied.

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7. Strut
- More struts are added.
- 8 double layer struts are used.
8. Final Bridge

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6.2 Final modelmaking
1. First, an accurate measured bridge drawing is drawn out to use as a template for
bridge making. Each truss is cut and trims with the exact length according to the
template.
Figure 14: Hand-drawn template for bridge design.
2. All of the components are cut out exactly to the length desired. Extension of
40cm I-beam is added at the bottom chord. The composition of the I-beam stack
is 1-2-2.
3. Next, 9cm middle chord that made up of 1 layer I-beam is glued on top of the
centre bottom chord.
4. Further up with four 1 layer hip vertical standing columns. These vertical
members serve as vertical pales for the fettuccine bridge to resist compression
force exerted.

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5. Following with 2 sets of 1 layer 45º diagonal members connecting the top of the
vertical member to the end of the horizon of bottom chord.
6. Next, two end post are added compelling the middle chord and bottom chord
forming an “A” shaped framing. The span of bottom chord is 40cm while the end
post is 35cm only to cut down unnecessary weight.
7. A few number of 3cm I-beam struts are glued in between both top chord and
bottom chord to stabilized and connect two trusses together.
8. 2 vertical I-beam trusses with 1-2-2 stacking together with 1 horizontal 1-2-2 I-
beam are placed literally on top of the bottom chord. It is constructed as a core to
carry the S-hook for the pail to rest on.
9. Lastly, 2cm butt joint is added to every splice of bottom chord to strengthen the
truss bridge.

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Formula of perfect truss bridge
2J = M + 3
2(12) = 21 + 3
24 = 24
Thus, it is a perfect truss bridge
Efficiency of bridge:
Efficiency:
Failure: End Post
Structure analysis:
1. Deflection
A major deflection can be observed. This is probably due to the two trusses at
the sides that aren’t perfectly parallel to each other.
2. End post
After reinforcing and having enough strength for the bottom chord, one of the end
posts breaks first.
102000g
66g
= 154.66

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8.0 Conclusion
By the end of this project, we had design and constructed a total of 7 fettuccine bridges
in order to achieve the highest efficiency of withstanding loads. With the help of the precedent
study, Waddell “A” Truss Bridge, we get to understand as well as learn more about the
construction of real truss bridge and to apply the essence into our own fettuccine bridge.
For the final model bridge testing, our bridge was unable to achieve the highest
efficiency among the 7 other bridges that were previously constructed. Nevertheless, our 6th
bridge has the highest efficiency, with the weight of 63 grams and total load withstand 10200
grams, an efficiency of 161.9E is achieved. Conversely, our final bridge was only able to
achieve efficiency of 151.5E withstanding a total load of 10000 grams and its weight 66g. This
project has made us understand more and allowing better comprehension on load distribution in
a structure. We also learned to calculate and identify the tension or compression force applied
on a structure member before constructing it in order to achieve highest efficient bridge design.
Furthermore, before constructing the final bridge, we had tried to play and experiment
with several beam and truss design in order to select the finest one for bridge construction.
Every trial and error while constructing the bridges has given us more in depth understanding
upon structural forces acted on various trusses.
In a conclusion, although we could not achieve the highest efficiency for the final bridge,
we were still very satisfied with our end product because each failure brings valuable lesson
and we had definitely learned a great deal in proper structural design in hope that we will be
creating a building that is safer with proper building structure.

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10.0Reference list
1. Ching. Francis D.K (2008) Building Construction Illustrated Fourth Edition. New
Jersey: John Willey & Sons, Inc.
2. L. C. Tartaglione. (1991) Structural Analysis. New York: Mcgraw Hill Book Co.
3. W.T. Marshall, H. M. Nelson. (1990). Structures, 3rd Edition. (Revised By Bhatt,
P. & Nelson, H. M.). London: Longman.
4. Chajes, A. (1990) Principles Of Structural Stability Theory: Second Edition.
Englewood Cliffs, New Jersey: Prentice-Hall, Inc.

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Case Study Conclusion
Of all the case studies that have been done by our group, case study 1 is concluded as
the best designed truss of all 4. Conversely, case study 2 is relatively weaker.
The load force of case study 1 has minimal interference acting in between; and is
distributed evenly within the truss members, none of the member carries extremely high load,
thus, lower down the chances of failure on a particular member. However, the load of case
study 2 is not distributed decently as it has a lot of concentrated load within one member. Case
study 1 also has high amount of tension force that providing more resistance force against
pulling comprised within the bridge as compared to bridge 2.
Furthermore, case study 1 has the least ‘zero force’ truss members in it, prove that all of
the truss members are functional and provide better load distribution throughout the whole
truss.

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