Lab Report
Title Page [1%] Title
Group name University Project dates Budget
Comparison of Load Managing and Structural Integrity between Beam
Bridges and Tension Bridges
The Tacoma Bridge Incidents City College of New York Project Dates: Budget: $1075.00
Abstract [4%]
Background
Purpose
Method
Obtained Results
Conclusive or Outcomes (Hypothesis)
Introduction
Bridges are structures built to traverse over obstacles, such as rivers and highways. Of the variety of bridge designs, this study compares the different weight tolerances between the tension bridge and the beam bridge. A beam bridge is designed to offload the stress onto the vertical pylons holding the bridge deck up. On the other hand this compression is only a part of the function of the tension bridge. A tension bridge uses vertical pylons which stretch further above the bridge deck in which tension wires are directly connected. These wires span the entire structure’s length and hold up the bridge deck while compressing the pylons. These bridges are built for different circumstances and must be able to withstand the traffic and stress passing over them.
1
This research was conducted to clarify these different circumstances by collecting experimental data on their respective weight loads and structural limits. Through these experiments, the data signified that the tension bridge had a higher weight load than the beam bridge and collapsed at a much slower rate.
Synthesis and Organization [15%]
Does the author clearly explain the research?
Does the author connect the research?
Does the author use transitions to create echoes in the paper? Does the lab report follow the IMRAD structure?
Does the lab report have clear headings?
Project Narrative (Methods)
The experiment is conducted with built miniature replicas, where the maximum weight load is tested by placing coins, specifically pennies, into a load tester. This experiment was repeated a total of three times and the average number of pennies required for structural failure was recorded.
The initial setup required for the beam bridge was as follows:
To build the pylons, two straight, non bendable straws were taped directly together on one end, with a shorter cut piece of straw put in between the straws on the other end, also taped together. Two pylons are constructed and taped to the same height on two opposing chairs. A full length straw is then placed into the opening of the pylons on each end above the shorter straw piece to act as the bridge deck.
Once this is done, a lightweight cup is hung at the center of the bridge deck to act as the load tester. To construct the load tester, one paperclip is shaped into a v and poked into opposite sides of the cup to hold it. Another paperclip is shaped into a hook and suspends the cup from the bridge deck.
To construct the tension bridge, the following step is taken:
Results [10%]
Is there an explanation of the collected data?
Are tables and charts used to explain the data?
Is the thesis evaluated? (Answer, does the data support the thesis?) Is the section written in past tense?
According to the data table below, the suspension bridge is more suitable to carry more weight than a beam bridge. We think that the cables on the suspension bridge allows less pressure on the weight of the actual bridge which allows it to carry more. The more trials we ran, the less the beam bridge was able to hold which shows its durability over time after every attempt. The suspension bridge was able to hold much more weight as well as hold it for a longer period of time. The suspension bridge data was also more spread out over time and was not decreasing
after every attempt. The beam bridge took most of the weight towards the middle of the bridge which led to the collapse
| Bridge design | Trial | Number of pennies | Average numbers of pennies |
| Beam | 1 | 76 | |
| Beam | 2 | 69 | |
| Beam | 3 | 56 | |
| Suspension | 1 | 136 | |
| Suspension | 2 | 150 (for about 6-7 seconds) | |
| Suspension | 3 | 140 |
Discussion [20%]
Are conclusions of the research explained and the significance reevaluated? Are study results compared with previous research?
Is this section written in the present tense?
Are in-text citations used when referring to previous studies?
Discussion: As expected, the suspension bridge was able to hold more weight than the beam bridge. The cables seem to take some of the weight off of the bridge itself making it last longer overall. For more populated areas, the more suitable bridge would be the suspension bridge because it would be able to handle a heavy load of traffic. This is the reason why there are such long suspension bridges like the George Washington Bridge in New York City or the Golden Gate Bridge in San Francisco. Beam bridges hold less weight for a shorter amount of time which is why they are used in less populated places to connect places to each other over a shorter distance. For the experiment, the types of chairs that were used didn’t have a solid surface which made it difficult for the bridges to stand. The issue was solved by taping the base of the bridge to books and then putting the books on the chair.
Bibliography [5%]
Is the bibliography in MLA formatting?
Are there six total sources?
Are there at least three scholarly sources?
Mechanics [10%]
Are there any spelling, grammar, and punctuation errors?
Are the paragraphs and sentences developed?
Are words used sparsely and effectively?
Is there consistency of font and text size throughout the paper?
