What wind speeds would it take to damage or seriously crack a concrete wall?

Question

What do you think of these examples?

http://images.google.com/imgres?imgurl=http://www.crh.noaa.gov/ilx/events/jul132004/wall1.jpg&imgrefurl=http://www.crh.noaa.gov/ilx/events/jul132004/jul13.php&h=640&w=480&sz=37&hl=en&start=1&um=1&tbnid=RLIZvcqMP56pHM:&tbnh=137&tbnw=103&prev=/images%3Fq%3Dtornado%2Bconcrete%2Bwall%2Bdamage%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG

http://www.erh.noaa.gov/lwx/Historic_Events/apr28-2002/laplata.htm

Answer 1

Usually it's debris that knocks down concrete walls; or the pressure is messed up and busts out the wall.  Debris from wind of 109 would cause little to no damage to a concrete wall; so it would have to be more than that.

An F5 or winds 261-318 mph would cause severe damage.

Answer 2

85 miles per hour and up.

That is enough speed to generate enough force on a building to move the upper frame, which generates more forces because of the weights of the building in motion, which then causes cracked concrete, pushed-out walls, fallen beams and total building collapses.

The buildings and structures do not fail to the wind speeds by themselves, they fail to the building leaning, twisting, etc; caused by the winds hitting a flat large-area wall of the building on one side, starting the building moving. The movements of the building/frame only has to be four inches to start the progressive failings you  see in the photos you referenced, and at 85 miles per hour, hitting the side of a 10 foot tall, 20 foot wide side of a building/structure (or bigger, area-wise), the assemblage of the building.structure will move over four inches somewhere within the three adjacent perimeter or interior walls.

There is a new building/structure frame reinforcing method recently developed (2005-2007) that reduces the frame movements to under four inches, up to 200 miles-per-hour winds, which is being marketed to Building contractors and Structural Engineers, called Structural Strap-Nets. These systems are tested and proven, and we are applying for our first Building Permit and Certificate of Compliance of one of our working prototypes in June, and hopefully, this will satisfy the Buildiers and Designers enough to take a serious look at these systems and start using them in disaster-prone regions soon!!

Answer 3

lol like 1000000000000000000000000000 mph lol idk