Slide 24 of 24
Notes:
GRAVITY FORCE-RESISTING SYSTEM
- What about gravity resisting elements?
- The figure shows the gravity resisting elements.
- Some of the elements of a gravity or vertical force-resisting system can and will be used to resist the horizontal loads.
- In the gravity force-resisting system there are live and dead loads transferred from the wood roof rafters to the walls.
- The live and dead load from the floor loads are transferred to the cripple walls, and then down to the foundations where they are resisted by the soil below them.
- Remember: Seismic alterations should not compromise the building
- When a building is altered in order to resist horizontal earthquake forces, the alterations should not compromise the ability of the gravity force-resisting system to support these loads.
- The purpose of the horizontal force-resisting system is to enable the gravity force-resisting system to maintain its support of the structure during earthquakes and windstorms.
- Most contractors understand gravity well.
- Important to understand that some elements of house structure resist both gravity and earthquake forces.