Earthquake engineering is a
sub-discipline of civil engineering that influences the life and property of
all human beings. It is this science that has provided an in-depth knowledge of
earthquakes, useful guidelines to minimize the damage due to earthquakes.
Earthquake engineering is the
science of the performance of buildings and structures when subjected to
seismic loading. It also assists analysing the interaction between civil
infrastructure and the ground, including the consequences of earthquakes on structures.
One of the most important aims of earthquake engineering is the proper design
and construction of buildings in accordance with building codes, so as to
minimize damage due to earthquakes. It is the earthquake engineer who ensures
proper design of buildings so they will resist damage due to earthquakes, but
at the same time not be unnecessarily expensive.
The purpose of these
technologies is to minimize the seismic effects on buildings and other
infrastructure by the use of seismic control devices. When seismic waves start
penetrating the base of the buildings from the ground level, the flow density
of their energy reduces due to reflections and other reasons. However, the
remaining waves possess significant potential for damage when they reach the
superstructure.
Vibration control devices
assist in the reduction of the damaging effects, and enhance the seismic
performance characteristics of the building. When the seismic waves penetrate a
superstructure, these are dissipated by the use of dampers, or dispersed in a
wide range of frequencies. Mass dampers are also employed to absorb the
resonant wave frequencies of seismic waves, thus reducing the damaging effects.
Seismic isolation techniques are sometimes used to partly suppress the flow of
seismic energy into the superstructure by the insertion of pads into or beneath
the load bearing elements in the base of the structure. Thus, the structure is
protected from the damaging consequences of an earthquake by decoupling the
structure from the shaking ground.
In order to properly
understand how buildings and structures can stand up to earthquakes, extensive
research has also been conducted on earthquakes.
In order to obtain an in depth
knowledge concerning the initiation and behavior of
earthquakes, it is essential to ascertain the mechanical properties and
frictional characteristics of the crust of the earth. Observations from space
have clarified the complete cycle of earthquake, including the silent
accumulation of strain, transfer of stress between faults, release of strain,
and failure of faults. Measurements on boundary zones of
tectonic plates have explained the
interaction of faults across hundreds of kilometers.
Study of the stress transients that take place after earthquakes will determine
the possibility of future earthquakes at other sites in the system. These
studies have provided scientific explanations related to earthquake engineering
and resulted in revision of concepts and practical application.