What types of structure are most prone to collapse in an earthquake? What types are most resistant to collapse?

Most prone to collapse during an earthquake are the structures that lack proper reinforcement, have a weak foundation, or are made from materials that cannot withstand ground shaking. Some common examples of these types of structures include: a) Unreinforced masonry buildings: These are buildings made of bricks, stone, or adobe blocks without any structural reinforcement. During an earthquake, they are more likely to collapse due to their lack of flexibility and inability to distribute stress throughout the structure. b) Soft-story buildings: These are multi-story buildings with a weak first floor, such as large open spaces, large windows, or insufficient columns to support the upper floors. When an earthquake occurs, the soft-story can collapse, resulting in the failure of the entire structure. c) Poorly constructed buildings: Buildings that do not adhere to proper building codes or were built using cheap materials have a higher chance of collapsing during an earthquake. Structural components may not be able to handle the forces exerted on them during earthquake shaking.

Structures that are most resistant to collapse during an earthquake have proper reinforcement, a strong foundation, and are made from flexible materials that can absorb and distribute the stress of ground movement. Some examples of these types of structures include: a) Reinforced concrete or steel buildings: These buildings have steel reinforcement embedded in the concrete, making them more resilient to earthquake forces. The ductility of steel can help the building deform without breaking, thus avoiding collapse. b) Base-isolated buildings: These structures are designed with a flexible base, which allows the building to move independently from the ground. This helps reduce the forces transferred to the building during an earthquake, which minimizes the risk of collapse. c) Shear wall buildings: These buildings have solid walls or rigid frames that are able to resist lateral forces from an earthquake. These walls help to distribute the stress and prevent the building from twisting or collapsing during an earthquake. d) Geodesic domes: These structures are constructed using a series of triangular elements that create a strong and stable framework. They are more resistant to collapse during earthquakes due to their geometry and efficient distribution of forces. In summary, structures that are most prone to collapse during an earthquake lack proper reinforcement, have weak foundations, and are made from inflexible materials, while structures that are more resistant to collapse incorporate strong and flexible materials, proper reinforcements, and innovative design methods that help dissipate earthquake forces.