Hello Ian:
ilox said:
And my heart goes out to all affected by this natural disaster. We watch the scenes on TV, heck I watched the progress and kept Strick informed while chatting across Skype. I still cant believe that much damage and destruction. Awful.
Yes, I too have been watching with disbelief at the damage to the area, and the corresponding suffering to the unfortunate soul's who could not or would not leave before the waters came through the levee's. I was not familiar with the geography of the city before now -- and that has me shaking my head in wonder.
A major portion of my career was as a Civil Engineer and programmer for the Bureau of Reclamation. That had me involved at the design level of many levee's and earth fill dams -- such as the San Luis dam in CA that I can see right now from the RV park where I am currently parked. So my first thoughts were about the levee design -- and the fact that the city was a disaster waiting to happen. There was a point in time (as you have probably heard on the news) when a decision was made to design for a Cat 3 vs. a 4 or 5. The reasoning was the incremental cost in millions (at that time) coupled with "probabilities" that a Cat 4 or higher would ever hit. I was never taught to include probabilities into design plans that I might sign off on.
While at Reclamation -- and at school at U of K, all design that I worked with placed all the potential loads on a structure, then placed a safety factor of 2 or more on top of that -- so those levee's should have been designed for a Cat 5 or 6 (if there is such a designation as a 6). I believe the numbers are exponential as with earthquakes in that a 6 is not a linear number above 5, but exponentially higher. Will never forget one of my structural design instructors at the U of Kentucky warning us that, "When a doctor makes a mistake, they bury it. When a Civil Engineer makes a mistake, they have a mass funeral". Looks like he was right.
So anyway -- that's the only "blame" thought I have and hope this thread can move in the direction of what have we learned and were do we go from here vs. another opportunity to bash our President, the government, the news media, or anyone else.