1. Bridging the Future
Kirk Elwall
Chapter 11

2. Key Points Engineers and architects A dead load and live load
Compression
Tension
Torsion
Thermal expansion

3. Engineers and architects
They work together to design structures.
The architect creates the look and form of the structure
The engineer makes sure that the structure can support the necessary loads

4. A dead load and live load
A dead load is any load associate with the structure itself.
A live load is any other force on the structure due to furniture's, traffic, snow, wind, earthquakes, and so on.

5. Compression Is a pushing force.
Occurs when two ends of an object are pushed toward each other

6. Tension Is a pulling force
Occurs when two ends of an object are moved away from each other.

7. Torsion Is a twisting force
Occurs when one side of an object twists relative to the other side.

8. Thermal Expansion A material Expands when it gets hotter
Shrinks when it gets cooler

9. Who is Kirk Elwell? City official Architect Urban planner
Field engineer

10. What are the main problems they try to solve?
Traffic congestion
Air pollution
Water pollution
Crimes

11. Which of the following defines bending?
Occurs when the ends of an objects are pulled away.
Is when one side of an object experiences tension and the other side experiences compression.
Is twisting force that results when one side of an object moves in a different direction than the other side.
Refers to part of a structure that projects into space supported at only one end.

12. List three examples of dead load and three of live loads.
Dead load: walls, floors, roof, beams, doorways, stairwells, elevator shafts, and so on.
Live load: students, teachers, snow on the roof, earthquakes, desks, cabinets, and so on.

13. How would these contribute to the construction project?
Architects would sketch out a design.
A structural engineer would be responsible to choose the necessary components to make building stand with a safety factor.
A field engineer would supervise the work when the building is being constructed in the way that the architect’s and structural engineer’s specification.

14. Some problems...
What is the minimum dead load (in tons) of a steel bridge that must carry 100 tons of traffic?
A scaffold has a dead load that is 60% of its total load. If the scaffold weighs 1,200 pounds, how much live load is it supporting?