From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
Date: Tue, 16 May 2000 09:37:16 -0400
Syed A Masroor wrote:
>>Any code that requires formwork design for seismic loads is ridiculous.
What is the probability of earth quake during the life of false
structure? I'd go by 0.01 probable level earth quake during the formwork
life. See what level excitation you get.<<
Let's see now. You are constructing a highway overpass; the superstructure
has just been poured; a couple of dozen concrete finishers are working on
finishing the concrete; a Northridge size earthquake hits; the formwork
collapses; the concrete falls; the reinforcing follows; the concrete
finishers follow; 6 dead; 10 disabled for life; more severely injured.
And you say that designing formwork for seismic loads is ridiculous? Ask
the contractor if it would have been worth the little extra cost to design
the falsework for seismic loads. Ask the survivors. Ask the disabled. Ask
the injured. Ask the jury.
Let us not get too tied up with probability. Probability is for gamblers and
abstract mathematicians, not for engineers who have to protect life.
A. Roger Turk, P.E.(Structural)