ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
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BUILDING STRUCTURES [ARC 2213] FETTUCCINE TRUSS BRIDGE ANALYSIS REPORT
LIM JIAN JUN 0316867 LOO MEI CHUEN 0316379 TEH GIE ENG 0316179 JOANNE BERNICE CHUA YUNN TZE 0315905 EVIN LOOI JYNN 0311852 TAN CUI ZHI 0320826
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
TABLE OF CONTENTS 1. INTRODUCTION 2. METHODLODY 2.1.PRECEDENT STUDY 2.2.MAKING OF FETTUCCINE BRIDGE 2.3.REQUIREMENT 3. PRECEDENT STUDY 4. MATERIALS & EQUIPMENTS 4.1.STRENGTH OF MATERIAL 4.1.1. PROPERTIES OF FETTUCCINE 4.1.2. TESTING OF FETTUCCINE 4.1.3.EXPERIMENTS 4.1.4.CONCLUSION 4.2.ADHESIVE ANALYSIS 5. BRIDGE TESTING AND LOAD ANALYSIS 5.1. TIMELINE 5.2. FIRST BRIDGE 5.3. SECOND BRIDGE 5.4. THIRD BRIDGE 5.5. FOURTH BRIDGE 6. FINAL BRIDGE 6.1. AMENDMENTS 6.2. FINAL MODEL MAKING
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3. JOINT ANALYSIS 6.3.1. JOINT A 6.3.2. JOINT B 6.3.3. JOINT C 6.3.4. JOINT D 6.3.5. JOINT E 6.3.6. JOINT F 6.3.7.JOINT G 6.4. FINAL BRIDGE TESTING AND LOAD ANALYSIS 6.5. CALCULATIONS 6.6. DESIGN SOLUTIONS 6.6.1. 1ST SOLUTION: FINGER JOINTS 6.6.2. 2ND SOLUTION: CROSS BRACING 6.6.3. 3RD SOLUTION: LOWER SUPPORT 7. CONCLUSION 8. APPENDIX 8.1. CASE STUDY 1 8.2. CASE STUDY 2 8.3. CASE STUDY 3 8.4. CASE STUDY 4 9. REFERENCES
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
1.0 INTRODUCTION This project aims to develop our understanding of tensile and compressive strength of construction materials by understanding the distribution of force in a truss. In order to achieve that, in a group of 6 we were required carry out a precedent study on a truss bridge of our choice, analyzing the connections, arrangements and orientations of the members. Once that was completed, we were required to design and construct a truss bridge made out of fettuccine. The requirements for this bridge include it having a 750mm clear span and a maximum weight of 200g. this bridge will then be tested to fail and we were required to analyse the reason of its failure and calculate its efficiency
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
2.0 METHODOLOGY 2.1 PRECEDENT STUDY By looking through precedent studies to have a better understanding of the types of trusses available. Next , understanding the forces that would be exerted to the trusses ; compression and tension, would allow us to make adjustment to our bridge, that would best suit the given material ; fettuccine.
2.2 MAKING OF FETTUCCINE BRIDGE
PHASE 01 : STRENGTH OF MATERIAL Understanding the properties of the fettuccine is important in order to build one bridge that can carry maximum load. For the tensile strength in the fettuccine is considerable low when compare to aluminium which has the same amount of stiffness to the fettuccine.
PHASE 02 : ADHESIVE Choosing the tight type of adhesive is important as it plays a huge role in this assignment. As there are many types of adhesive in the market that each has their own function and characteristics. Not only the type of adhesive is important but the brand of adhesive is important as well, for different brand has different quality and choosing one that suits constructing the fettuccine bridge is primary. PHASE 03 : MODEL MAKING
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
To ensure precision in our model making, AutoCad drawings are drawn in 1:1 scale and plotted out to ensure precision and ease our process. And in order to strengthen our bridge as much as possible, each pasta is marked individually as each has their own location of placement and length, and are glued accordance. PHASE 04 : MODEL TESTING Finished models are being tested after placing aside to allow the adhesive to sit on the model. By placing weight on the middle of intermediate member to ensure that load is evenly distributed. All these are being recorded to allow us to fix and analysis our bridge.
2.3 REQUIREMENTS • To have a clear span of 750mm • Not exceeding the weight of 200g • Only material allowed is fettuccine pasta and adhesive • Allowed to use any type of adhesive possible • Workmanship is put to consideration as part of aesthetic
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
3.0 PRECEDENT STUDY
Fig 3.0.1 Linn Branch Creek Bridge in 1898
Historic name Waddell “A” Truss Bridge Other name Linn Branch Creek Bridge Location English Landing Park, Parkville, Missouri
History The Waddell “A” Truss Bridge, currently located in English Landing Park in Parkville was designed by engineer John Alexander Low Waddell. It was originally built in 1898 as a railroad bridge across Linn Branch Creek before being abandoned in 1939, and was relocated in 1987
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
to make way for the construction of Smithville Lake. As of now, it crosses Rush Creek carrying a pedestrian path between a day-use recreational area and two isolated ball fields. The single span bridge is a U.S. National Register of Historic Place with a patented design, consisting of triangular ‘A’ trusses and its structural members are pin-connected. Despite its relocation, the bridge retains its integrity of design due to its reliability, ease of erection, cost efficient and structural rigidity in all directions. Comparison and Components of Bridge
Fig 3.0.2 Bridge constructed across Linn Branch Creek in 1898
Fig 3.0.3 Bridge relocated to English Landing Park, Parkville, Missouri in 1987
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Portal'bracing
Fig 3.0.4 Portal View
Strut
Diagonal'
Hip'ver1cal Upper'
Guard'rails Bo4om'
Fig 3.0.5 Perspective Elevation View
 
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Force Distribution Diagram of Bridge under Load Pressure
In'tension Under'compression Fig 3.0.6 Force Distribution Diagram
Arrangement, Orientation and Connection of Bridge Members (Drawings by John Alexander Waddell) Connec1on'of' members
Load
Connec1on'of'strut' and'upper'chord
Fig 3.0.6 Connection of Members
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Fig 3.0.7 Detailed truss connection of members
Pin'joint' connec1on
Eleva1on'of' portal'bracing
Sec1on'view' of'pin'joint' (line'6E6'in'Fig'
Fig 3.0.9 View of bracing below deck of bridge
Sec1on'view'of' middle'chord' (line'7E7'in'Fig'
Fig 3.0.8 Detailed Drawing of Portal Bracing and Pin joint connection
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
4.0 MATERIALS & EQUIPMENTS Equipments
Pen Knife
• used to cut the fettuccine in model making
Camera
• make recordings of the bridge testing • photograph the process
Bag
• carry the load
Hook
• hook the bag on the bridge
Sand Paper
• sand the edges of the components of the bridge to fit
Mineral Water
• used as load
Weighing Machine
• measure the weight of the load placed inside the bag
Super Glue
• adhesive for material bridge
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
4.1 STRENGTH OF MATERIAL Fettuccine was the only material approved to be used for this project. Thus, research and analysis of Fettuccine was conducted before model making session.
Figure 4.1.1 Fettuccine used in model making.
4.1.1 PROPERTIES OF FETTUCCINE The fettuccine used in the making of the truss bridge model has the thickness 1 mm and the width of 4 mm. It is brittle and thus is stronger under tension. However, fettuccine has a low compressive strength 1. Ultimate tensile strength : 2 000 psi 2. Stiffness (Young’s Modulus) E: 10, 000, 000 psi ( E= stress/ strain)
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
4.1.2 TESTING OF FETTUCCINE Before the testing, we made sure the fettuccine are glued with the proper technique to prevent uneven surface and to ensure the ease of building with modular units.
Figure 4.1.2.1 Wrong glueing technique
Figure 4.1.2.2 Correct glueing technique
4.1.3 EXPERIMENTS: The fettuccine beams were formed using the staggered arrangement to ensure that the breaking points are not aligned and thus minimising the the number of weak spots.
Figure 4.1.3.1 Staggered arrangement of fettuccine in beam
To understand its efficiency and the maximum load each can carry, we tested several types of beam with different orientations to understand which is the best to be implemented in our bridge building.
Figure 4.1.3.2 Vertical Facing
Figure 4.1.3.2 Horizontal Facing
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Layers of Members
Length of Clear Span fettuccine (cm) (cm)
Load Sustained (Vertical Facing) (g)
Load Sustained (Horizontal Facing) (g)
1 Layer
26
15
420
205
2 Layer
26
15
500
320
3 Layer
26
15
770
630
4 Layer
26
15
1300
1110
5 Layer ( I-beam)
26
15
-
1700
4.1.4 CONCLUSION Based on the testings, it can be concluded that the I-beam made up of 5 pieces of fettuccine is the strongest among all as it could withstand the heaviest load. The 4 layered fettuccine is also quite strong. For the 1 layered and 2 layered fettuccine, it shows that the the horizontal facing fettuccine is much stronger compared to the vertical facing ones.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
4.2 ADHESIVE ANALYSIS Three different kinds of glue used to ensure the joints are strong and thus strengthen the bridge.
Type of Adhesive Advantage V-Tech Super Glue UHU glue
Epoxy
Disadvantage
• • •
High Efficiency Fast Solidifying Time Easy to Use
•
• •
Rank
•
Makes fettuccine brittle Causes joints to crack
1
Easy to Use
• •
Low Efficiency Slow Solidifying Time
2
Stronger
• • •
Low Efficiency Slow Solidifying Time Difficult to use (needs to be mixed)
3
V-Tech Super Glue was used the most while constructing our fettuccine bridge. It has high efficiency and it dried faster compared to the other adhesives, as it is more concentrated when compare to UHU glue as well as epoxy. To make sure the glue worked as its best, allow the glue to settle in the bridge to make sure it is dry before the testing it. This is to ensure the bridge perform at its best. UHU glue is avoided if possible, as it causes the joints to be flexible. It also requires longer time to dry, making it the less appropriate option, for joints should be rigid. Epoxy, even though it is stronger, it is less efficient as it requires a lot more time to solidify and is difficult to use. It requires the mixing of epoxy and hardener in small batches. Hence, the bridge is at its optimum condition after at least 4 hours of drying using the super glue.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
5.0 BRIDGE TESTING AND LOAD ANALYSIS 5.1 TIMELINE Date
Work Progress
13th April 2015
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Testing of strength of fettucine by using 1,2 and 3 layers and using I-beam design Discussion and research on suitable truss for precedent study
15th April 2015
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Testing different ways of fettucine joints and using different kinds of adhesive to test the strength
16th April 2015
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Discussing and making decision on which truss design to proceed and construct Making of first bridge model
18th April 2015
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Load testing of first bridge and proceeded with making the second bridge model.
22rd April 2015
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Load testing of second bridge and proceeded with making the third bridge model
24th April 2015
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Load testing of third bridge and proceeded with making the fourth bridge model
25th April 2015
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Load testing of the fourth bridge and proceeded with making the final bridge model
26th April 2015
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Continue session with the making and refining final bridge
27th April 2015
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Final submission and load testing of final fettucine bridge
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
5.2 FIRST BRIDGE We used the precedent study, the Waddle “A� Truss Bridge, as a guideline for our first bridge. In this first trial, we did not restrain ourselves too much on the weight of the bridge, but more on reinforcement, adhesive, joints and orientation of the trusses.
Figure 5.2.1 The design of our first bridge
Figure 5.2.2 Our bridge before testing
Figure 5.2.3 Horizontal member failed
The failure only occur at the horizontal member (Figure 5.2.2), because the member is bearing the highest load and are too thin and weak to carry the load by itself without distributing the load around (figure 5.2.3).
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.2.4 Diagram showing poor load distribution of the horizontal member
Bridge weight: 215g Load: 1813g Efficiency: (1.813)2 = 15.3%
 0.215 Failed Components :
Horizontal member
Failing Reasons :
Member is too thin, poor load distribution
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
5.3 SECOND BRIDGE After consideration, we decided to use waffle slab to replace the broken member of our first bridge. Gussets and joining methods are further explored and applied into the bridge. Refining using sandpaper is done and the second test is performed.
Figure 5.3.1 Load distribution diagram
Figure 5.3.2 Load distribution diagram of the
Figure 5.3.3 Top elevation of the waffle slab
waffle slab
In Figure 5.3.1, it shows the transition of load acting on the bridge is from the middle of the bridge to the sides of the bridge, to improve the load distribution. The bottom chord and all the connecting members are in tension, whereas the top chord and all the diagonals are in compression.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.3.4 Top chord failed
Figure 5.3.5 Bottom chord failed
Figure 5.3.6 Waffle still intact after testing
Figure 5.3.7 Bridge after load test
Figure 5.3.8 Top chords are curved upward and downward caused by rough workmanship
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.3.9 Failed component
The failures occur at the top chords, because they are too thin and were not able to withstand the compression force, causing them to buckle (Figure 5.3.4). Hence, the top chord layer should be thickened by adding more fettuccine. Other than that, the top chords are not properly constructed (Figure 5.3.8) and have caused uneven members, joining and force distribution. After the load test, the waffle slab is still intact (Figure 5.3.6) and was able to withstand more load than the first design. This shows the waffle slab is a better and improved design.
Bridge weight: 229g Load: 5120g Efficiency: (5.120)2 = 114.5%
 0.229
Failed Components :
Top chord due to buckling
Failing Reasons :
Thin top chord member, uneven load distribution caused by rough workmanship
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
5.4 THIRD BRIDGE The load distribution of the Baltimore Truss Bridge we did for our third bridge (figure 5.4.1) works the similar way with our first and second bridge (figure 5.3.1), where all the top chord and diagonal members are under compression while all the vertical members are under tension. After analyzing our first two bridges, we have decided to make these improvements to increase our efficiency of the bridge. Amendments made: 1. Lowering the height of the bridge from 165mm to 70mm (to decrease the bridge weight) 2. Place each of the center vertical member of each triangle on top of the horizontal member (to increase even force distribution) (Figure 5.4.2 and Figure 5.4.3)''
Figure 5.4.1 Load distribution diagram
Figure 5.4.2 Placement of each member on our second bridge (left) and on our third bridge (right)
Figure 5.4.3 Joint on third bridge
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.4.4 Bridge before testing
Figure 5.4.5 Bridge shows the downward bending causing the bottom chord to break first
Figure 5.4.6 The bridge failed due to the downward
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
In this design, the breaking first occurs at the bottom chords (Figure 5.4.5). The compression and tension is too great compared to the first design due to its height, and the bottom chords are not strong enough to sustain the force thus they break first. Placement of each of the center vertical member of each triangle on top of the horizontal member has caused the joints to have a smaller and unstable joining contact point (Figure 5.4.3). This has caused the vertical member to slip out of the original position after testing due to the compression and has contributed to the breaking of the bridge. Other than that, when load is applied, the bridge started to bend downwards at one side of the bridge due to the uneven force distribution caused by the uneven sizes of the trusses and inconsistent distances between joints (Figure 5.4.5). This is caused by the difficulty of maintaining the workmanship when there are too many joints in this bridge. '
Figure 5.4.4 Failed component
Bridge weight: 205g Load: 4222g Efficiency: (4.222)2 = 87.0%
 0.205 
Failed Components :
Top chord and bottom chords
Failing Reasons :
Too many joints, uneven load distribution caused by rough workmanship
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
5.5 FOURTH BRIDGE After testing and analyzing the second and third bridge, we decided to improvise a new design by improving it but still using our precedent as a guideline. Amendments made: Figure 6.4.4 Failed Component
1. Rising the height of the bridge (increase bending resistance) 2. Place every vertical and diagonal member on top of the bottom beam (for direct joining contact point and more surface area for more stable joining) 3. Making one whole triangle instead of few triangles (to decrease the number of joints)
Figure 5.5.1 Load Distribution Diagram for the 4th Bridge
Figure 5.5.2 Bridge design before testing
''
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.5.3 Picture shows the sliding of the bridge.
Figure 5.5.4 Bridge flips due to the torsion, height, breaking of the bottom chord and the narrow base
Torsion
Figure 5.5.5 Top view diagram shows torsion, causing the two main facades to slide against each other
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 5.5.6 Failed component
Failure occurs due to the torsion of the two bridge main faรงades sliding left and right against each other. Other than that, the height of the bridge and a narrow base ultimately have also caused the whole bridge to flip over. The absence of the diagonal and cross bracing has lead to the torsion and caused our bridge to fail. Thus, we have applied the diagonal bracing in our next bridge.
Bridge weight: 254g Load: 4732g Efficiency: (4.732)2 = 88.2%โ จ 0.254
Failed Components :
Bottom chords connecting members
Failing Reasons :
Torsion, bottom chords (the two main bridge facades) are not connecte with each other with cross bracing to prevent torsion
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.0 FINAL BRIDGE 6.1 AMENDMENTS The figure below (figure 6.1.1) shows the design and construction method of our final fettuccine bridge. This type of truss bridge had been chosen for our final model design as it reaches the highest efficiency among all the truss bridges we have tested. Referring to the test result, in depth analysis was conducted for further development in order to achieve higher efficiency. Amendments made: 1. Amendments of dimension Dimension of distance in between each vertical member had slightly been changed (figure??). The length of each distance was changed from ??mm to ??mm, to enable the vertical members rest on the edge of tables (allow force from the edge of table transfer directly to the vertical member, and to prevent failure of the horizontal member)
790
Figure 6.1.1 Amendments of dimension of final bridge model
Figure 6.1.2 Dimension of the first bridge model
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.2 FINAL MODEL MAKING Firstly, an accurate Autocad drawing of the bridge is printed out as a guide for the bridge construction. Then, the two I-beams are constructed:
Figure 6.2.1 Diagram showing first step of erection, the I-beam.
6.2.2 Picture showing staggered I-beam construction
6.2.2 Picture showing staggered I-beam construction
Figure 6.2.4 A close up picture of the I-beam showing the construction and orientation
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Secondly,'the'outline'of'the'three'triangles'are'constructed:'
Figure 6.2.5 Diagram showing second step of erection, the outline of the triangles.
Figure 6.2.6 Picture showing the joining of the
Figure 6.2.7 Picture showing the joining of the
triangle
triangle to the I-beam
Figure 6.2.8 Picture showing us securing the joints using masking tape
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Thirdly, the vertical members and the top horizontal members are constructed. These vertical members serve as vertical posts for the fettuccine bridge to resist the compression force that was created:
Figure 6.2.9 Diagram showing third step of erection, the vertical members and top horizontal chord
 
Figure 6.2.10 Picture showing the vertical and top horizontal chord are joined to the triangles
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
The forth step is carried out immediately, the diagonal and the small vertical members are constructed. The diagonal members were located at gaps in between vertical members and they functioned as bracing of truss which is able to resist shear force. '
Figure 6.2.11 Diagram showing forth step of erection, the vertical members and top horizontal chord
 
Figure 6.2.12 Picture showing two main facades of the bridge
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Lastly, a series of members having 60mm in length is served to connect the bottom and top chords two main facades (Figure 6.2.14). The position is determined to be at the bottom of each vertical member and rested well above the bottom chord. Other than that, another series of members with the same length are placed above the top chord of the bridge with horizontal facing (Figure 6.2.17). Diagonal bracing at the bottom chord is constructed (Figure 6.2.16). Waffle slab is constructed in this step too (figure 6.2.15), same time with the joining of the two facades.
Figure 6.2.13 Diagram showing last step of erection, the vertical members and top horizontal chord
'
Figure 6.2.14 Pictures showing the joining of the two main bridge facades
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
 
Figure 6.2.15 Picture showing the construction of the waffle slab
Figure 6.2.16 Pictures showing the diagonal bracings
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 6.2.17 Picture shows connecting members of vertical facing at bottom chord and horizontal facing at top chord
Figure 6.2.18 Final bridge before testing
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3 JOINT ANALYSIS Joining method is one important factor in a bridge design as the joints will affect the efficiency and failure of Fettuccine bridge. The joints are further tested and studied to achieve the optimum joining of every single member at different part of connections. Therefore, respective methods of joint are designated according to requirement of each part.
A
C
B
D
F
E
G
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3.1 JOINT A
Previous Joint Design
Improvised Joint Design
Figure 6.3.1 Joint A Connection Amendment
It was studied that the vertical member at the joint A experiences compression forces when load is applied to the design. From the previous design, we analyzed that the jointed members carrying the compressive internal are causing stress to the structure member while connecting to one another. Action is taken to separate the joints and the joining method of two members is designed so that the vertical member is supporting the upper diagonal member and not affecting the internal force of other members.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3.2 JOINT B
45째
Figure 6.2.1 Joint B Gusset Reinforcement
The middle most diagonal members are joined with butt joint, leaning again each other with a fixed angle of 45 degree. The rigidity of the triangle structure provides stability and strength to force acting on it, and distributing evenly from member to members. Reinforcement of the joint is introduced with the use of gusset. The gussets hold the members together to prevent gliding of members due to the brittleness of the adhesive material used when load is added to the structure.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3.3 JOINT C
Figure 6.3.3 Top Horizontal Member Connection
The top chord horizontal chords are designed in segments to accommodate the compressive stress of the structure. The segmented members are preferable rather than one long strip of horizontal member. This is because the longer stretched member is more fragile than a shorter one when a load is applied to the structure. The segmented members allow better resistance on compressive stress. The end of the segment members are carefully shaped to sit firmly to the side of the diagonal members.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3.4 JOINT D
Figure 6.3.4.1 T-lock Connection
Figure 6.3.4.1 Example of a slotted steel plate
T-lock joint is a design connection acting like a steel plate in steel construction. The T-shape member is slotted into the I-beam and holds the beams up right to prevent downward bending force from the load itself. The connection gives better structural strength to connect both vertical and horizontal members perpendicularly.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3.5 JOINT E
 1st Design
2nd Design
3rd Design
Fig 6.3.5.1 Improvement on Vertical Member
Fig 6.3.5.2 Photos of Divergence of the Vertical Facing the Connecting
The vertical facing connecting members is one critical design to evenly distribute the load along the entire structure of the bridge. The improvement was made from the very first design of the member, which was attaching to the vertical member. The design was not efficient as it does not spread the load along the bridge but acting as a load itself, giving more stress to the structure. Furthermore the load is actually depending all by the adhesive material (glue) only. The 2nd improvised design was made better because the members lay on the I-beam. But the vertical members joining the vertical facing connecting members are not strong due to its poor
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
contact surface area of both vertical and vertical facing connecting members. The 3rd design was considered to transfer the vertical facing connecting members to the sides, diverting load stress to the other part of the bridge with less concentration of members.
6.3.6 JOINT F
Fig'6.3.6''Connec1on'of'ver1cal'facing'connec1ng'members. This vertical facing connecting beam is simply laid perpendicularly to the long bottom chord of the I-beams. These short members are glued in stacks and then fixed on top of the stretch. These members function as the load distribution member to channel and balance out downward loads along the stretch of the bridge.
6.3.6 JOINT G
Fig'6.3.7''Connec1on'of'bracing
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
The connection joint G is placed diagonally on the I-beams to resist shear force as well as torsion force acted on the structure by the load. These bracings are fixed in between the vertical facing connecting members at the lower part of the bridge. The bracings rest against the other members to prevent movement and distortion of other structural members of the bridge.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.4 FINAL BRIDGE TESTING AND LOAD ANALYSIS The picture below (figure 6.4.1) shows the design our final fettuccine bridge and the load distribution.
Figure 6.4.1 Design of our final bridge and members in tension and compression diagram
In this final bridge, the main amendments made are size and height of the bridge (to provide better downward bending resistance and stable force distribution), and the use of diagonal bracing at the bottom chord (to prevent the bridge from torsion).
Figure 6.4.2 Top view of our previous bridges (without diagonal bracing)
Figure 6.4.3 Top view of our final model (with diagonal bracing)
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
 
Figure 6.4.4 Bridge before testing
Figure 6.4.5 Bridge showing torsion at the top chord before breaking
Figure 6.4.6 Top chords break and caused the bridge to fail
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 6.4.7 Bridge before load is applied
Figure 6.4.8 Bridge showing downward bending after load is applied
 
Figure 6.4.9 Top chord breaks due to torsion and has caused the whole bridge to fail
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
After observing, calculating and analyzing our bridge, we have concluded that in this final design, the failure occurs due to the torsion at the top chord (Figure 6.4.5). When the load is applied, the top chord of the bridge experienced torsion due to the uneven forces distribution caused by the design of the trusses. By referring to Joints E, I, M, E1, I1 (top chord), we can conclude (from observation and calculation) that Joints E, M and E1 are in equilibrium, whereas Joint I and I1 are not in equilibrium. At Joint I and I1 (which their resultant forces are not in equilibrium), they are experiencing a large upward force at their Y-vector, with a magnitude of 204.82N. Whereas the others points are in equilibrium. With this great upward force, they have contributed to the torsion at the top chord in this pattern shown in the figure 6.5.11 and caused failure to the bridge.
Figure 6.4.10 Picture showing torsion pattern at the top chord
 
Figure 6.4.11 Top view diagram showing torsion and statues of each joints
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
The diagram above shows Joints in red bubble (I and I1) experiencing torsion and are not in equilibrium, whereas Joints in blue bubble (E, M and E1) are in equilibrium, thus remained in position. The bridge testing results do tally with the calculation. Other than that, when load is applied, the bridge started to bend downwards due to the uneven force distribution caused by the design of the trusses. By referring to Joint K and Joint C/G (after calculation): In Joint K, it is experiencing a downward force at its Y-vector, with a magnitude of 123.41N. When compared to the adjacent weaker joints, Joint G and C, they experience an equivalent lesser downward force at its Y-vector, a magnitude of 42.09N and 42.17N, The big difference of magnitude between these joints has caused the downward bending of the bridge, and ultimately causing the bridge to fail.
Figure 6.4.12 Diagram shows big difference in magnitude of force between the joints, causing downward bending
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
Figure 6.4.14 Failed component
Bridge weight: 203g Load: 4170g Efficiency: (4.17)2 = 85.7%
 0.203
The efficiency of the final bridge did not meet our expectation as the bridge should be able to carry more loads and have higher efficiency. Due to the great torsion at the top chord and the adhesive is not fully dry, our final model was only able to have a 86% efficiency.
Failed Components :
Top chords
Failing Reasons :
Torsion at the top chord, glue is not fully dried
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.5 CALCULATIONS$
4.17 kg= 4.2 = 42N 1) Determine perfect truss 2J = 2(24) = 48 M + 3 = 45+3 =48
2) Determine reaction force ∑MA= 0 ( 42 x 0.39) - (Ra x 0.78) = 0 16.38 - 0.78Ra = 0 Ra = 21N
Therefore 2J = M + 3, it is a perfect truss ∑Fy= 0 42N – 21N- RA = 0 RA = 21 N
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
3 ) Determine internal forces of main structural member
At joint A,
∑Fy= 0 21-FAB sin Q = 0 FAB sin 47.12 = 21 FAB = 21/ 0.73 FAB = 28.77 ( C)
At joint C,
∑Fx= 0 -19.58 + FCD = 0 FCD = 19.58 (T)
At joint B,
∑Fx= 0 FAB cos θ – FAC = 0 -FAC = cos 42.12 x 28.77 FAC = - 19.58 ( T ) tan θ = 0.07/ 0.065 θ = 47.12°
! ∑Fy= 0 (-FBE sin θ ) +(-21) + (+FBC)+ (+21) = 0 F=FBC – FBE sin θ = 0 ° FBC = 42.1697 FBC = 42.17 (C) ∑Fx= 0
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
(-FBE cos θ) + (+19.58) + (+19.58) = 0 -0.6805 FBE = - 39.16 FBE = 57.5459 = 57.55 (C)
At joint F,
At joint D,
∑Fx= 0 (-19.58)+(-21)+(21)+(19.58)=0 ∑Fy= 0 (+19.58)+(-FED) + (+19.58)=0 FED = 39.16 (C)
At joint E,
∑Fy = 0 (-21) + (81.33)+ (-FFH sin θ ) + ( FFQ) = 0 60.33 – 0.7328 FFH + FFG =0 FFG = 42.09 (C) ∑FX= 0 (-19.58)+(-75.53) + ( FFH cos θ) =0 FFH 0.6805= 95.11 FFH = 139.76 (T)
∑Fy= 0 (57.55 sin θ ) + (39.16) + (- FEF sin θ) = 0 42.17 + 39.16 – FEF 0.7328 = 0 FEF = 110.99 ( T) ∑FX= 0 (57.55cos θ) + (- FEI ) + ( FEF cos θ ) = 0 39.1608 + FEI + (110.99 X 0.6805)= 0 FEI = 114.69 (C)
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.6 DESIGN SOLUTIONS 6.6.1 1ST SOLUTION: FINGER JOINTS
Figure 6.1.1 Proposed improvement on joint method
By using Finger Joints, this maximises the areas to be glued for joining compared to our previous joint which is the Butt Joint. This increases the the strength and durability of the joint as it requires a lot of force to separate the parts.
6.2 2ND SOLUTION: CROSS BRACES
Figure 6.2.1 Proposed addition of strong cross bracing at top chords
Cross braces pushes the the two top chords against one another, thereby increasing the structure’s stability. It also holds the two chords in place by resisting torsion caused by the load.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
6.3 3RD SOLUTION : LOWER SUPPORT
Figure 6.3.1 Proposed lower support for bridge
By adding supports below the bridge, the load is distributed to the supporting objects; the table. This also reduces the chance of buckling of the lower chord as it transfers the load away from the vertical hip that is in compression. 
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
7.0 CONCLUSION We had constructed a total of 5 fettuccine bridges experimented its efficiency in withstanding loads. The precedent study we chose to study on is Waddell A ‘Truss bridge’. We had concluded on using Waddell A ‘Truss bridge’ because of the single span bridge with a patented design, consisting of triangular ‘A’ trusses and its structural members are pinconnected. Despite its relocation, the bridge retains its integrity of design due to its reliability, ease of erection, cost efficient and structural rigidity in all directions In our final model testing, we achieved the highest efficiency compared to the previous 4 models we have done. Our fettuccine bridge achieved an efficiency of 114.5% withstanding a total of load of 5120g and its weight is only 229g. This project has made us understand load distribution in a structure deeper, compared to the previous semester, as we are now able to calculate the type of force applying in each structure member. We explored different arrangement of structural members and realized it is important to identify the force (tension/ compression/zero/critical) in structural members in order to achieve a high efficient bridge design. We also realized the importance of proper planning, in terms of work delegation and the time interval between completion of bridge and load testing. It is due to the efficiency of completing the bridge on time and giving an adequate time for the adhesives to dry out and maintain its strength until load testing. In conclusion, it has been a great experience working on this project. Using household goods to construct a bridge and gaining so much knowledge after that have amazed us how strong a structure can be if it is properly designed and constructed . As an architecture students, we will be the leader in the construction industry in future, we need to think critically and pay attention to details so that a structure can function efficiently without failure for the safety and well being of the people.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
8.0 APPENDIX As for our individual part, we were assigned to further analyse total of 5 trusses. Each were distributed to following :
8.1 FIRST CASE 8.2 SECOND CASE 8.3 THIRD CASE 8.4 FOURTH CASE 8.5 FIFTH CASE
The analysis and calculation of trusses are attached after this page.
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ARCH 2213 BUILDING STRUCTURES PROJECT 1: Fettuccine Truss Bridge Analysis Report
9.0 REFERENCES National Register of Historic Places. (n.d.). Retrieved May 6, 2015, from http:// dnr.mo.gov/shpo/nps-nr/90002173.pdf Patent US529220 - Truss-bridge. (1894, November 13). Retrieved May 6, 2015, from http://www.google.com/patents/US529220 Ching, Francis D.K (2008) Building Construction Illustrated Fourth Edition. New Jersey: John Wiley & Sons, Inc.
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