36.14.2. Vertical-to-Horizontal (V/H) Ratio

Try these first

1. 1.

   What does the V/H ratio represent?

   Hint

   Think about how vertical and horizontal ground motions relate.

2. 2.

   What is a typical range for the V/H ratio?

   Hint

   Recall the numbers that represent this ratio from our discussions.

3. 3.

   What is the typical range for the V/H ratio?

   • 0.1 to 0.2
   • 0.3 to 0.7
   • 0.8 to 1.0

   Hint

   Recall our discussions on V/H ratio values.

4. 4.

   True or False: The V/H ratio is unnecessary in the design of tall buildings.

   • True
   • False

   Hint

   Consider the forces acting on tall structures during an earthquake.

5. 5.

   An engineer observes that during a seismic event, the vertical response at a site required a V/H ratio of 0.45 for accurate design. If the site-specific horizontal spectrum has a peak ground acceleration (PGA) of 0.8g, what is the adjusted vertical PGA?

   Hint

   Use the scaling formula involving V/H to adjust the values accordingly.

6. 6.

   Discuss the potential consequences of applying a uniform V/H ratio of 0.5 across different soil types when designing a multi-story building. How would your approach differ if the building were to be constructed on soft soil versus hard rock?

   Hint

   Consider how soil characteristics affect ground response.