Earthquakes, Aftershocks and the Role of Shear Testing
Earthquake Testing
According to long-term records, approximately 17 major earthquakes (magnitude 7.0 - 7.9) and one great earthquake (magnitude 8.0 or above) can be expected to occur in any given year (USGS, 2014). This figure has remained fairly constant, despite more earthquakes being recorded each year due to the rapid growth in seismograph stations installed throughout the world.
The damage caused to infrastructure by earthquakes varies considerably, depending on the location of the earthquake, the mechanical characteristics of the soil layers affected, the depth of the water table, and the intensity and duration of the earthquake. Deposits of soft soils can lead to amplification of shaking at the ground surface for example, while the contractive tendencies of loose granular materials can result in soil liquefaction and differential settlements taking place. Such response may also impact lifelines such as power and water, alongside the more visible damage to infrastructure.
Understanding the behaviour of soils when shaken by an earthquake can allow engineers to increase the resilience of future infrastructure. Here at GDS we have developed a range of apparatuses to approximate these loading conditions and provide valuable knowledge needed to develop foundation and structural design solutions in areas vulnerable to earthquakes.
