7.1.6. Design Considerations for Spans

Try these first

1. 1.

   What is the primary load-bearing mechanism of arches?

   Hint

   Think about how they are designed to handle forces.

2. 2.

   Define the span-to-rise ratio.

   Hint

   How does it relate to the height of the arch?

3. 3.

   What is a key advantage of the parabolic arch?

   • It is more aesthetic
   • It minimizes bending moments
   • It is simpler to construct

   Hint

   Think about how the shape affects load distribution.

4. 4.

   True or False: A three-hinged arch may develop internal stresses from movement?

   • True
   • False

   Hint

   Consider the design purpose of three hinges.

5. 5.

   You are tasked with designing a new arch bridge. Given varying live loads expected to act on segments of the arch, propose strategies to maintain structural integrity using deployment of materials and design shapes. What factors must be considered?

   Hint

   Focus on load distribution variability and impact on design.

6. 6.

   A historical arch bridge has a rise of 10 ft and a span of 80 ft. Analyze its stability with a proposed increase in the rise to 15 ft. What are the expected changes in horizontal reaction H?

   Hint

   Use the formula correctly and compare values before and after the change.