Hypothesis:
The Bridge with the Cross Bracing system will withstand various levels of seismic shock longer than the bridges with V bracing, and diagonal bracing systems.
(my hypothesis was accepted.)
My Abstract:
This experiment was done in the hopes of finding out which bridge bracing system would be the best to use in a bridge for seismic shock resistance (earthquake resistance). After a month or so of research three types of bridge bracing systems were tested (Cross Bracing, V-bracing, and Diagonal bracing). Nine truss bridges total were made from wood glue and balsa wood sticks. They were then tested on an earthquake simulating machine. The machine tested three different sets of magnitudes which included 2.5-5.4, 6.1 -6.9, and 7.0 -7.9. Pictures were taken all throughout the experiment and results and observations were taken down. During the testing the v- bracing seem to have the most damage but it took more time to instill it, unlike the diagonal, whom failed earliest but not as dramatic. Dissimilar to both of these, the cross bracing took longest and had very few broken pieces. In the results, the bracing system that did the best was cross bracing, next v-line and lastly diagonal. Their average times were 11 minutes, 5 minutes and 30 seconds, and 4 minutes and 2 seconds. These findings showed that cross bracing would be the better choice to use in a real life bridge or building in order to withstand seismic shock.
My Applications : The knowledge gained from this experiment can be used to better understand why certain bracing styles are used more often around areas with faults lines, or that are prone to sudden earthquakes. It can also be used in the field of civil engineering and structural engineering to illustrate what might happen to certain bridges that come in contact with seismic shock. This could potentially aid them in making decisions on which patterns to use, how to improve bracing systems in a design and also in reinforcing older structures that might not have this suitable bracing systems for the area. The information from this experiment can be very advantageous in different countries that struggle with earthquakes such as Haiti and Chile (Part of HPMG News). Having most of my family living in Haiti, I watched this even very closely when it occurred and because of the way the buildings were built and the mountainous landscape many buildings and even 2 important bridges were damaged. Most of the buildings we have in Haiti are old and they use common vertical and horizontal perpendicular bracing. This type of bracing would not last very long when it comes to and earthquake of a high magnitude. I believe that if they had the knowledge gained from an experiment like this they would improve their systems of bracing, and reinforce the new homes that are being build there. Even if it were to be a few minutes difference or even hours, that extra window of time could easily be used to save someone’s life.