Question

According to the IBC, a soft story is a story in which the lateral stiffness is less than ___% of that in the story above or less than ____% of the average stiffness of the stories above.

Answer 1

A soft story is when the lateral stiffness is less than 70% of the story above or less than 80% of the average stiffness of the three stories above, which can make a building vulnerable during earthquakes.

Step-by-step explanation:

According to the International Building Code (IBC), a soft story is a story in which the lateral stiffness is less than 70% of that in the story above or less than 80% of the average lateral stiffness of the three stories above. A soft story is particularly vulnerable during seismic events because the reduced stiffness and strength in one story relative to the others can lead to a concentration of movement and potential failure at the location of the soft story. Identifying and reinforcing soft stories is an important aspect of seismic retrofitting to ensure the safety and integrity of a building during an earthquake.