This week we were fascinated to find out that special engineering techniques are used to create buildings that can endure a modest or even strong earthquake. However, during a very strong quake, many buildings will still suffer severe damage. Engineers design buildings to withstand as much sideways motion as possible, in order to minimise damage to the structure and give the occupants time to get out safely. Ms Atkins talked to her class about how these designs are used in Chile and prevented too much damage in the 8.8 earthquake she experienced there in 2010. Comparatively, a far less powerful 7.0 earthquake in Haiti a few weeks earlier had caused huge devastation, with poor building design and construction playing a major part in this.
Armed with our new knowledge, we held class competitions to create the tallest spaghetti structure that would withstand an earthquake (created by our teachers!) We realised that our buildings needed to be strong yet flexible, in order to withstand ground motion. Many groups included shock absorbers or ‘base isolation’ as part of their design. Some thought about connecting the walls, floor, roof, and foundations to create a box shape. This was designed to hold together and move as a unit when shaken, rather than cracking and collapsing. We also learnt to build with a lightweight roof and walls to minimise damage if parts did fall! Another technique to dampen the swaying of a tall building is to build in a mass that can sway at the top, acting as a balance. These are known as ‘mass dampers’ but proved quite tricky to create from the materials we had!
Teamwork was an essential part of this activity and we all had lots of fun creating and testing our designs together. Clearing up all the broken spaghetti on the floor afterwards wasn’t quite so much fun! The activity also made us thankful that we don’t have to worry about the dangers of serious earthquakes here in the UK.