Shanel Sighn, Haley
Lopez, Cayla
Andrews, Hector
Gonzalez.
Earthquakes
Our science topic is how to build a building that will be most stable in any
type of earthquake. Earthquakes, by definition are the trembling and shaking of the
earth. Earthquakes occur at fault lines, fault lines are where tectonic plates meet.
Seismographs are used as a way to record the force of an earthquake at a location
and most seismographs are placed near fault lines. The seismographs also measure
after shocks and their intensity. There is no perfect way to make a fully earthquake
proof building, but our topic is to get it as close to perfect as possible. In our
experiments, we build many different buildings and shake them to see how an
earthquake would affect the type of building.
During earthquakes one thing that we are surrounded by are buildings. You
do not want the building you are in to collapse because the architect did not think to
earthquake proof their buildings. There were two main building types that we
looked at, rigid and flexible. The flexible is assumed to be better but too much
flexibility is not a good thing either. A building with too much flexibility would bend
al the way over even if it doesn’t collapse like grass in the wind. The rigid building
are obviously not a good option either because they would not be able to move at all
and would snap or collapse under the pressure of an earthquake. To test these types
of buildings we made buildings, one was made out of Lego’s as a model of a stiff
building and when we shook them they broke off in huge chunks. But for the flexible
buildings, we used stick pieces and when we shook them we noticed how they shook
really fast and was constantly tipping. We concluded from these experiments that
flexible buildings are not safe because how they constantly move, and when you are
caught un an earthquake, you would rather not want to shake with the earthquake
because it might cause a lot of damage and injuries. Stiff buildings are not good
either because even though they are stiff, they will easily just break easily, for
example a piece of chalk is hard to swish when your holding it up, but its easy to
break it in half with just a little pressure, which is similar to what will happen to stiff
buildings.
Some other experiments that we did to determine what a good enough
building will be like were with clay and dental floss where we put different size
clays balls or different lengths of strings on dental floss and move our hand slowly
and watch which swings faster or slower and what makes causes them to do this. By
doing this we measure frequency by counting how many times the ball swings back
to its original starting point. The reasoning of this experiment was to figure the
connection between frequency and mass. For example when we moved the two
strings with the same force that had different amounts of clay on the bottom, it
showed the change in frequency depending on the mass. So basically, the clay
represented a water tower, which helped us understand frequency better. When
understood it we made a formula for the building which is frequency=higher length
/lower mass.
Another experiment that we did was build a model building out of straw and
dental floss, on the sides of the building we put a cross that connected the diagonals
of the corners together, making a big X on the sides which is called a brace frame.
What this X does in the brace frame is keeps the building a little more stable
building so if it would be shaken by an earthquake it will be supported on all sides of
the walls. The reason for this was a to see what kind of structures and techniques
we could use to keep the building from completely collapsing.
We have proven that neither works because we created models of a flexible
and rigid building and the rigid one broke off in half. The flexible on came apart in
one side and just flopped over. Instincts do not come in handy when making a
structure for a building.