Efforts to manage earthquake risks involve prediction, forecasting, and preparedness, including seismic retrofitting and earthquake engineering to design structures according to the building code of the country that will withstand shaking.
The aftershock of an earthquake occurs after a previous earthquake. Rapid changes of stress between rocks and the stress from the original earthquake are the main causes of aftershocks. An aftershock is in the same region as the main shock but always of a smaller magnitude, however, they can still be powerful enough to cause even more damage to buildings that were previously damaged from the mainshock.
Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings and other rigid structures. The severity of the local effects depends on the complex combination of the earthquake magnitude, the distance from the epicenter, and the local geological conditions.
Physical damage from an earthquake will vary depending on the intensity of shaking in a given area and the type of population. Underserved and developing communities frequently experience more severe impacts from a seismic event compared to well-developed communities. Impacts may include injuries and loss of life, damage to critical structures, disruption of roads, bridges, and public transportation networks, water, power, sewer and gas line interruption, disruption of Communication systems, loss of critical community services including hospitals, police, and fire services, general property damage, collapse or destabilization different of buildings and so on.
With these impacts and others, the aftermath may bring disease, a deficiency of basic requirements, mental consequences such as panic attacks and misery to survivors. Regaining times will vary based on the level of damage and the socioeconomic position of the obstructed community. Earthquakes can cause fires by disruption of electrical power or gas lines connectivity. In the event of water mains shattering and a loss of pressure, it may also become difficult to stop the spread of a fire once it has happening.
While forecasting is usually measured to be a type of prophecy, earthquake forecasting is often distinguished from earthquake prediction. Earthquake warning systems have been advanced that can provide regional warning of an earthquake in progress, but before the ground surface has begun to move, potentially permitting people within the system's range to seek shelter before the earthquake's effect is felt.
The objective of earthquake engineering is to foresee the influence of earthquakes on buildings, bridges, tunnels, roadways, and other structures, and to plan and design such structures to minimize the danger of damage. Prevailing structures can be modified by seismic retrofitting to improve their resistance to earthquakes. Emergency management plans can be active by a government or organization to ease risks and prepare for consequences. Artificial intelligence may help to evaluate buildings and propose cautionary procedures.
Individuals can also take preparation steps like safeguarding water heaters and heavy items that could wound someone, positioning shutoffs for utilities, and being educated about what to do when the shaking begins. Zones near large bodies of water, earthquake preparedness involves the possibility of a tsunami caused by a large earthquake.
The steps to earthquake safety includes Secure own space, Plan to be safe, organize disaster supplies, minimize financial hardship, Drop, Cover, and Hold On during shaking, improve safety after the shaking stops, and reconnect and restore individual life afterward. These steps involve preparing home and family before, taking action during, and recovering after an earthquake.
Earthquake mitigation in Dhaka involves both implementing modern seismic building codes for new projects and retrofitting existing vulnerable structures following Bangladesh National Building Code (BNBC). Buildings should be appropriately designed incorporating shear walls or bracing systems that resist lateral forces. With flexible materials which can absorb energy and sway during an earthquake without sudden failure is vital. Reinforced concrete with a flexible steel skeleton is ideal over breakable materials like unreinforced brickwork. Dhaka's high risk of soil liquefaction needs special consideration to robust foundation to prevent undermining during a quake. Educating landlords and the community about the importance of seismic safety and mitigation is essential for safer construction. Strict enforcement of the building code and consistent monitoring of construction by government authorities like Rajdhani Unnayan Kartripakka (RAJUK) and the Public Works Department (PWD) is essential.
If an earthquake happens, all individuals need to evacuate in a damaged area afterward. By planning and practicing for evacuation, any individual will be better ready to respond suitably and efficiently to signs of hazard or to instructions by civil authorities.?
In a periodic interval, examine the structural safety of every house constructed by reinforced concrete structures. If the house is of conventional wood construction, it will probably be relatively resistant to earthquake damage, hence wooden structures are relatively safe for an earthquake prone area. Particularly if it is a single-story structure.
The writer is a civil engineer; presently serving in Military Engineering Services as a Lieutenant Colonel of Bangladesh Army
