On an almost weekly basis, Murat Saatcioglu sets off an explosion similar to the 1995 Oklahoma City bombing in downtown Ottawa.
In his underground lab in the University of Ottawa’s civil engineering building, Prof. Saatcioglu is using a high-pressure shock tube to simulate and study the effect of terrorist bombs on buildings.
When a bomb goes off, damage is caused by a number of different effects, said Saatcioglu.
A fireball will burn everything. Then a tremendously high-pressure shockwave of air will go over buildings, turning fragments of debris into projectiles moving as a fast as bullets.
Fire, shock and fragmentation all kill people in equal number, but in terms of structural performance, the shockwave is the most important aspect, said Saatcioglu.
The shock tube enables Saatcioglu to research infrastructure protection by simulating the power blast shockwaves in their lab without people outside the building having a clue that it happened.
“We measure how much they would deform, how much they would be stressed and how much reinforcement should be placed where, so they could sustain the high air pressures that travel as super sonic velocities,” said Saatcioglu.
Without the shock tube, he would have to do his tests at an army base using real explosives.
“It’s not easy to control that environment whereas this is a controlled environment,” he said.
“This gives us a chance to repeat these test many times and use trial and error to come up with the right amount of material in the right place.”
The tube allows them to simulate up to three explosions per day, though since they are collecting so much data from each explosion, Saatcioglu said it’s more like one of two per week.
The purpose of the research is to develop design techniques so that buildings and bridges would withstand blast-induced shockwaves.
Saatcioglu said they are concentrating on the performance of base columns. In the 1995 Oklahoma bombing and the World Trade Centre, damaged base columns led to a progressive collapse.
Part of their research is to develop new construction techniques that will translate into a new Canadian Standards Association construction standard in around two years. The other part is developing reinforcing options for existing buildings.