40.21.1. Dynamic Effects on Bridges

Try these first

1. 1.

   What is modal analysis?

   Hint

   Think about vibrations and natural frequencies.

2. 2.

   What do bearings do in bridge design?

   Hint

   Consider how movement affects structures.

3. 3.

   What is the purpose of modal analysis?

   • To determine structural aesthetics
   • To assess bridge responses to seismic forces
   • To calculate material costs

   Hint

   Consider why understanding vibrations is important.

4. 4.

   True or False: Bearings are only designed for static loads.

   • True
   • False

   Hint

   Think about what happens during an earthquake.

5. 5.

   A long-span bridge undergoing modal analysis shows a natural frequency close to the dominant seismic frequency of the region. What should the engineer consider doing in the design phase?

   Hint

   Think about frequency interactions during seismic events.

6. 6.

   Design a hypothetical bridge using bearings and describe how they would function during an earthquake. Include the types of forces they would mitigate.

   Hint

   Focus on the relationship between earthquake forces and structural movements.