1. Earthquake Basics Section 2

2. +What causes earthquakes? +How do earthquake forces enter buildings? +How does the building respond? +What building elements resist forces?

3. Strike-Slip Fault

4. Thrust Fault

6. EpicenterEpicenter FaultFault Point of fracture or slippage, termed Focus or Hypocenter

7. California Index Map

8. Distance to Fault Source Surface Geology Water Sand Rock Fault

9. Liquefaction Failure

10. Inertia Forces ACCELERATIONACCELERATION DECELERATIONDECELERATION

11. HD1HD1HD2HD2 ElevationElevation HD3HD3HD4HD4 Height / Weight Relationship 0101 1½1½ 0120123

12. Building at Rest Ground Accelerates to Left Ground Accelerates to Right Ground & Building at Rest Period of Vibration

13. Chimney Vibration Failure

14. Porch Vibration Failure

15. Two Story Vibration Failure

16. Shear Wall Cripple Wall Foundation Floor Diaphragm Floor Diaphragm Roof Diaphragm House Elements Resist Horizontal Forces f1f1 f2f2 f3f3 f sum = f 1 + f 2 + f 3

17. Cripple Walls Crawl Space Cripple Wall First Floor

18. Damage Resulting from Base Shear

19. Buildings Resist Horizontal Earthquake Forces +Horizontal parts: Roof & floor structures diaphragms +Vertical parts: Span horizontal elements shear walls

20. Complete Load Path

22. No Shear Wall at Garage

23. Steel Moment Frame

24. House Elements Resist Gravity Roof Joists Walls Floor Beams Foundations