6.5. Seismic Excitation as Base Motion

Try these first

1. 1.

   Define seismic excitation.

   Hint

   Think about how earthquakes affect buildings.

2. 2.

   What is relative displacement?

   Hint

   Consider how the building's motion relates to the ground.

3. 3.

   What does seismic excitation refer to?

   • Ground shaking
   • Wind forces
   • Mass movement

   Hint

   Remember the context of earthquakes.

4. 4.

   True or False: Absolute displacement includes both relative displacement and ground displacement.

   • True
   • False

   Hint

   Think about how each type of displacement contributes.

5. 5.

   An earthquake causes the ground to move up and down by 4 inches. If a structure moves in a way so that its relative displacement during the same time is 1 inch up, what is its absolute displacement?

   Hint

   Add the ground displacement to the relative displacement.

6. 6.

   Describe the effects of neglecting base motion in structural modeling during an earthquake. What potential risks could this introduce?

   Hint

   Consider the implications of ignoring external forces acting on buildings.