Your Assignment: Invent a specific quake and imagine yourself in it. Open the template I have sent you on Phy Sci resources. You are going to write about your earthquake from three view points; News reporter, scientists, and eyewitness.
Earth Quake Causes They occur in Zones that coincide with the edges of the Lithospheric plates. (crust and upper section of the mantle) Deformation of the earths crust: – Compression – Tension; stretched – Shear; move opposite directions – Torsion; twisted
Earthquake waves Focus; the point of origin Epicenter; on the surface directly above the focus. http://cse.ssl.berkeley.edu/lessons/indiv/davis/inprogress/QuakesEng3.html
What happens to buildings in an Earth quake? They sway from the ground floor up. Taller buildings are more flexible and sway more. Shorter buildings shake to pieces.
Seismic Safe Structures A structure that is resistant to the vibrations from earthquakes. It will still be standing!!!!! The building and foundation need to be built to resist the sideways motion (load). Diagonal bracing. Allow the structure to move as a unit and not shake. Dampers that can absorb the motion so it is not transferred to the building.
Building material that absorbs motion. Large bearings ( rubber or springs) in the foundation Make structures that can bend. Strengthening the foundation and securing the building to the foundation
Diaphram Diaphragms are horizontal resistance elements, generally floors and roofs, that transfer the lateral forces between the vertical resistance elements (shear walls or frames). Basically, a diaphragm acts as a horizontal I-beam. That is, the diaphragm itself acts as the web of the beam and its edges act as flanges. (See figure 1) http://mceer.buffalo.edu/infoservice/reference_services/basicseqdesign.asp
Shear wall Shear walls are vertical walls that are designed to receive lateral forces from diaphragms and transmit them to the ground. The forces in these walls are predominantly shear forces in which the fibers within the wall try to slide past one another.