The commonness of seismic activity reports coming out these days is enough to make one think the planet is generally prone to disasters. This may or may not be true, but it has been proven time and again how damaging an earthquake or even a tremor can be, especially in areas with closely space buildings. Regardless of where these occur, engineers and architects often stress that inadequately constructed buildings cause more harm than earthquakes do per se.
Nowadays, a majority of the efforts comprising a building project are routed into ensuring that the structure is made resistant to earthquakes. While it is possible to go a step further and make them earthquake-proof the costs involved make it a non-viable endeavour in most cases. The onus instead, is to design buildings in ways that preclude collapse so that human life and construction budgets are preserved. With tremendous advancements having been made in recent years, the subject is hardly a new one. This is obvious from the fact that so many ancient structures around the world are still standing, some of them showing only the wear brought on them by the elements since the time of construction.
Admittedly, the techniques used today to preserve newly built structures are different from what was used in the past, but the two share some common principles. These basics deal with the forces that act during the time an earthquake acts.
The Effect On Buildings
Earthquakes are caused when massive rocks in the crust slide against each other, and this occurs along a fault line. If the rock breaks, the lines formed can reach hundreds of miles in length. When these pieces of rock slip and move, they give out tremendous quantities of force, which then flow through the crust and in the form of seismic waves. On the surface, these waves can make the ground shake and vibrate in a violent fashion.
Symmetry Of The Building
Engineers are tasked with determining the seismic risks posed by the site, following which they propose an adequate building design that normally steers clear of irregular or asymmetrical designs. These designs are capable of raising visual appeal, but on the downside, they are also prone to torsion or twisting. For this reason, seismic engineers prefer keeping buildings symmetrical in order that the forces get distributed equally.