Earthquake and geotechnical engineeringEarthquake engineering is a branch of civil engineering responsible for protecting society against natural disasters such as earthquakes. This branch of civil engineering mainly studies the behavior of structures when they are struck by a seismic wave. The main responsibilities of earthquake engineers are to design structures capable of withstanding an earthquake and to ensure that all structures meet required building codes. Additionally, they must estimate the likely damage to structures after an earthquake. Many lives have been lost due to the collapse of structures during an earthquake. As mentioned in class, an earthquake will never kill anyone, but it is the results of an earthquake that kill people. In 1909, more than 100,000 people died in Italy after an earthquake due to poor structures and lack of preparation. Sometimes people are injured not because of earthquakes, but because of landslides or tsunamis that occur after an earthquake. Safe structures are structures that do not endanger the lives of people inside or nearby by completely or partially collapsing after or during an earthquake. Critical structures such as hospitals, nuclear power plants, schools and dams are not only built to survive an earthquake, but also to remain in service. Extra money is always spent when building these structures to ensure they will survive an earthquake. Engineers establish all building codes based on precise calculations based on theories and actual observations known as seismic evaluation. . There are two different types of seismic performance evaluations: experimental evaluation and numerical evaluation. Experimental evaluations are very expensive because engineers must construct a m...... middle of paper ...... Engineers study soils and rocks to ensure or investigate whether a surface or subsoil is suitable for building a structure on or in it. An important thing that geotechnical engineers do is double-check the location of the foundation and whether the soil underneath can withstand the amount of stress being exerted. If soil evaluation reveals a problem in its properties, the problem can be resolved through soil improvements, such as treating the soil mass. These processes saved a lot of money and time and allowed buildings to last longer. Soil mechanics studies are the studies most closely linked in geotechnical engineering to geology. It analyzes site conditions and soil properties. Many soil properties need to be checked, such as Atterberg limits, which are the shrinkage limit. This indicates how much the soil would shrink due to weather conditions and water limits..