The devastating consequences of earthquake can be seen throughout the world, and can have a tremendous impact on our built environment. When the ground shakes, buildings can collapse in a matter of seconds, leaving people dead or injured, and causing extensive damage. But why do some buildings collapse during earthquakes while others nearby remain unharmed?
What determines if a building will collapse during a strong quake or not? In this blog post, we are going to explore some of the reasons for why some buildings remain standing even in the face of a major earthquake, and how construction can be optimized to minimize the risk of catastrophic damage.
We will look at the different aspects of construction and design that can reduce the likelihood of a building crumbling during an earthquake. We will also look at how building codes and regulations are designed to promote earthquake-resistant structures.
Finally, we will examine the role that seismic testing and monitoring can play in making buildings safer and more resilient.
1. Strength of building materials used in construction
One of the most important factors that determines if a building will collapse during a strong earthquake is the strength of the building materials used in construction. Buildings constructed with higher quality materials, such as reinforced steel and concrete, are less likely to succumb to the seismic forces of an earthquake.
On the other hand, buildings constructed with lower quality materials, such as wood and masonry, are more likely to collapse. Additionally, the design of the building’s foundation plays an important role in its ability to withstand an earthquake.
Buildings constructed with deep foundations are less likely to collapse than those with shallow foundations.
2. Method of construction and architectural design
Building construction and architectural design are two of the most important factors to consider when determining whether or not a building is likely to collapse during an earthquake. Structural integrity and earthquake-resistant design principles are essential when constructing a building that is designed to withstand the forces of an earthquake.
In order to create a structurally sound and earthquake-resistant building, architects and engineers must consider the types of materials used, the building’s structural integrity, and the load-bearing capacity of the building’s frame.
Also, the building’s design must account for the properties of the local seismicity and the seismic waves that will be encountered when an earthquake occurs. If these factors are not properly addressed, the building will be more likely to collapse during an earthquake.
3. Distance from the epicenter of the earthquake
One of the main factors that determines if a building will collapse during an earthquake is its distance from the epicenter of the quake. Buildings that are located close to the epicenter of the earthquake typically experience a greater amount of shaking than those located further away. As a result, the closer the building is to the epicenter of the earthquake, the more likely it is to collapse.
The buildings that are located close to the epicenter may experience more severe ground motion than buildings farther away, which can also lead to increased likelihood of collapse.
Therefore, distance from the epicenter of the earthquake is an important factor when considering why some buildings collapse during earthquakes while others nearby remain standing unharmed.
4. Quality of soil and geology in the area
One of the key factors that determine whether buildings collapse during earthquakes or not is the quality of the soil and geology in the area. Different soils and geological formations can affect the way a building responds to an earthquake in different ways.
For example, soft soils such as clay are less able to absorb the energy of the ground motion and can cause buildings to sink or tilt. On the other hand, soils that contain a lot of gravel or sand are often able to absorb the energy of an earthquake and cause less damage to buildings.
Geology also plays a major role, as certain formations can amplify or reduce the force of an earthquake. Therefore, the quality of the soil and geology in an area can be a determining factor in whether buildings collapse during earthquakes or not.
5. Building height
Building Height: Generally, the taller a building is, the more likely it is to collapse in an earthquake. Taller buildings are more likely to sway, and the sway can increase their risk of collapse.
Buildings that are taller than four stories are more prone to collapse in an earthquake due to the amplified effect of swaying. Furthermore, taller buildings require deeper foundations, which may not be able to withstand an earthquake.
6. Positioning of columns and beams
One of the most important design considerations when assessing the safety of buildings during earthquakes is the positioning of the columns and beams. Buildings collapse during earthquakes when the columns and beams are not adequately secured, or when the structures are not designed to withstand the seismic forces.
Proper positioning of columns and beams is essential for ensuring the stability and strength of the building so that it can withstand the ground motion of an earthquake without collapsing.
This is why it is crucial to consider the structural design and positioning of columns and beams when constructing a building to ensure that it will not collapse during an earthquake.
7. Level of seismic activity in the area
It is important to consider the level of seismic activity in the area when determining why some buildings collapse during earthquakes while others remain standing unharmed. This is because the strength of the ground shaking (referred to as PGA) from the earthquake increases exponentially with a higher level of seismic activity.
As a result, buildings in areas with higher seismic activity may experience more intense ground shaking during an earthquake, which can cause damage to buildings that are poorly designed or constructed.
Therefore, buildings in highly seismic areas must be designed and constructed to withstand the expected level of ground shaking, in order to reduce the chance of buildings collapsing during an earthquake.
8. Quality of construction work
Quality of Construction Work: The quality of construction work dictates how well a building will withstand an earthquake. If the foundation and the superstructure are not built properly, with the right materials and to the right specifications, the building is much more likely to collapse during an earthquake.
Poor construction can weaken the building’s frame, making it more vulnerable to shaking and more likely to collapse. Poor construction can also cause structural damage, which can increase the severity of the collapse.
9. Use of anti-seismic devices such as dampers and ties
When earthquakes strike, buildings collapse due to the severe vibration of the seismic waves. However, some buildings remain standing unharmed amidst the destruction. The difference between the two is due to the use of anti-seismic devices such as dampers and ties.
Dampers, also known as base isolators, are devices that absorb the shock of an earthquake by decreasing the seismic waves’ power.
Ties, on the other hand, are structures built to keep the building intact by connecting its columns and walls with stronger and flexible materials. With the use of these anti-seismic devices, buildings are able to withstand earthquakes and prevent them from collapsing.
10. Maintenance and stability of the building over time
Maintenance and Stability of the Building over Time: Buildings must be regularly maintained in order to remain standing during earthquakes.
This includes ensuring the building foundations are regularly assessed and reinforced, if necessary, to ensure they can withstand the force of an earthquake. Additionally, any seismic retrofitting that needs to be done should be carried out to ensure the building is stable and able to remain standing during an earthquake.
Regular maintenance also helps to identify any potential problems with the building, such as instability or weak foundations, which could lead to a collapse during an earthquake.
In conclusion, the safety and stability of a building during an earthquake is determined by its design and construction. Buildings that are designed and constructed to meet seismic codes, regulations and standards have a much greater chance of surviving an earthquake.
It is important to have buildings inspected regularly to ensure they are safe and up-to-date with the latest seismic codes, and that any repairs or retrofits are done as needed. By following these steps, property owners can ensure the safety and stability of their buildings in the face of seismic activity.