Introduction
Living on the west coast, there is often talk about earthquake preparation and preparedness. Living in Vancouver, surrounded by water, there are many bridges. How stable are these bridges going to be in case of an earthquake? This is where the idea for our science expo project came. We plan to test three common bridge designs in order to see which design hold up the best in a simulated earthquake.
The Lionsgate Bridge is a suspension bridge so we will be constructing a suspension bridge made from popsicle sticks. Suspension bridges can be built longer than any other bridge. The main principle is that cables are strung from the bridge to towers which are then connected by cable to anchorages on land. The arch bridge is another bridge design that we will be testing. This design has been around for over two thousand years. It was originally designed by the Romans. When built using stone, no mortar is necessary to hold the stones together; the forces of tension and compression held it in place. Our third model will be a beam bridge, most often used in Pedestrian bridges and Highway overpasses. The girder bridge is simple and may only consist of a beam laid across two supports.
We have a few ideas to test these bridges under simulated earthquake conditions. It would be too expensive for us to buy an earthquake simulation table and too time consuming to build our own. One practical idea is to use jello. By making jello in a disposable tin foil pan then setting the bridges on top of the jello, we can shake and tap the pan to simulate compression waves. It would be difficult to keep the force of the simulated earthquake constant in all three trials, however. Another option is to see which bridge hold to most weight by using gram and kilogram cubes. This option would not demonstrate how earthquakes affect our bridges but it would be easy to keep other variables constant.
After beginning our experiment it became clear that building an arch bridge from popsicle sticks would be very difficult. Instead of an arch bridge we will now be building a box girder bridge. It is similar to a beam bridge but it has triangular support systems over top to increase durability.
Living on the west coast, there is often talk about earthquake preparation and preparedness. Living in Vancouver, surrounded by water, there are many bridges. How stable are these bridges going to be in case of an earthquake? This is where the idea for our science expo project came. We plan to test three common bridge designs in order to see which design hold up the best in a simulated earthquake.
The Lionsgate Bridge is a suspension bridge so we will be constructing a suspension bridge made from popsicle sticks. Suspension bridges can be built longer than any other bridge. The main principle is that cables are strung from the bridge to towers which are then connected by cable to anchorages on land. The arch bridge is another bridge design that we will be testing. This design has been around for over two thousand years. It was originally designed by the Romans. When built using stone, no mortar is necessary to hold the stones together; the forces of tension and compression held it in place. Our third model will be a beam bridge, most often used in Pedestrian bridges and Highway overpasses. The girder bridge is simple and may only consist of a beam laid across two supports.
We have a few ideas to test these bridges under simulated earthquake conditions. It would be too expensive for us to buy an earthquake simulation table and too time consuming to build our own. One practical idea is to use jello. By making jello in a disposable tin foil pan then setting the bridges on top of the jello, we can shake and tap the pan to simulate compression waves. It would be difficult to keep the force of the simulated earthquake constant in all three trials, however. Another option is to see which bridge hold to most weight by using gram and kilogram cubes. This option would not demonstrate how earthquakes affect our bridges but it would be easy to keep other variables constant.
After beginning our experiment it became clear that building an arch bridge from popsicle sticks would be very difficult. Instead of an arch bridge we will now be building a box girder bridge. It is similar to a beam bridge but it has triangular support systems over top to increase durability.