Intro to Systems
John Small
21 November 2017
Cypress Viaduct Failure Inquiry At 5:08 pm the Point Loma earthquake begins. Within seconds the cypress viaduct begins to vibrate. This is due to the bay clay on which it is built which intensifies the vibrations. The upper deck is insufficiently secured to the lower deck and the areas near the shear keys begin to degrade. As concrete begins to fall away the resonant frequencies cause these weak points (columns with shear keys) to fail along a 1.7km section killing 35 and trapping many more. One is reticent to say it is lucky that the world-series were occurring so fewer people were on the road however the casualties are considered to be lower than they would have otherwise. The collapse …show more content…
The bay clay has an amplifying effect of the vibrations being as it caused the sections it was built on to vibrate up to 5 times more than that of sections built on other types of geological surfaces. (Elnashai) It was also learned that the insufficient number of upper supports in combination with the way in which they were secured to the lower tier was the actual point of failure. This failure was due to the inelastic nature of the shear keys and their inability to dissipate lateral shear force causing them to vibrate and shake off supporting concrete. After the first support failed the remaining supports failed quickly in succession as the structure lost its integrity. The upper supports only broke as a result of the shear key failures. Now computer modeling accomplishes simulations of catastrophic events and such stressed be accounted for prior to the completion of large concrete and steel structures such as this. …show more content…
It is our duty to think of as many points of failure as possible so that we may consider them in our designs. It is our duty to make sure that the people who lose their lives in such tragedies serve as lessons to the community that we can always improve something and that we can always learn from our failures. Engineering failures occur all the time. Look at the exploding Samsung batteries. They will continue to occur. That is the nature of human progress. We answer one question only to find that we have more questions. Each failure that occurs always begs the same question, why? When we answer why we can move forward and hone our craft. Why is often the most important question we must ask ourselves? Now I find myself asking why across a larger spectrum of problems as what is the world we live in but a series of interconnected