During the semester Introductions Basics of earthquakes History and Recording Damaging Earthquakes and Understanding seismic exposure Undertaking loss assessment Seismic analysis; and design and detailing (RCC and Masonry)

Recent Seismic Event

Try reading different tabs at /earthquakes/recenteqsww/Quakes/us2011ggbx.php#scitech Alternate link Which Plates?

Basics of Earthquake resistant Construction

Construction Type Infrastructure – How much critical? – Such as Bridges, Power Plants, Industrial sheds, etc. Housing – Occupancy levels (high or low?) – High density or Rural

Basics of Earthquake resistant Construction Classify as: Foundation Super-Structure Design of both and compare stiffness and strength capacities

Basics of Earthquake resistant Construction

Foundation Damage

Basics of Earthquake resistant Construction Foundation Damage Chuetsu earthquake-earthquake liquefaction

Basics of Earthquake resistant Construction Ground Settlement

Basics of Earthquake resistant Construction Foundation Damage

Basics of Earthquake resistant Construction Foundation Weaknesses Liquefaction Temporary loss of strength in soil, which acts like a fluid. Differential settlement Over an area, non-uniform settlement of soil. Represented by different COMPACTION levels. Lateral Spread Movement /settlement Lateral movement of loose soils Landslide In slopes. Critical factors are- 1) Slope angle, 2) Soil type, etc. Ground Cracking Large crack or Lurching in form of irregular ground surface cracks Subsidence Vertical movement of ground surface. Rare.

Basics of Earthquake resistant Construction Foundation Weaknesses Liquefaction

Basics of Earthquake resistant Construction Foundation Weaknesses Differential settlement

Basics of Earthquake resistant Construction Foundation Weaknesses Lateral Spread

Basics of Earthquake resistant Construction Foundation Weaknesses Land Slide

Basics of Earthquake resistant Construction Foundation Weaknesses Ground Subsidence (Rare)

Structural Weakness

Symmetry Centre of Gravity and Geometry. Regularity Vertical and Horiz. Openings Spacing and size Soft Storey effect Change in Stiffness, mass, strength and ductility Local eccentricity Pounding Control deflection Other Items with a potential to fall. Such as- Long cantilevers, partition, badly fixed non-structural components Basics of Earthquake resistant Construction

List of Codes and standards related to Earthquake Engineering List – IS 1893:1984 Criteria for Earthquake Resistant Design of Structures – IS 1893(Part 1):2002 `Criteria for Earthquake Resistant Design of Structures : Part 1 General provisions and Buildings – IS 1893(Part 4):2005 `Criteria for Earthquake Resistant Design of Structures: Part 4 Industrial Structures Including Stack Like Structure – IS 4326:1993 Earthquake Resistant Design and Construction of Buildings - Code of Practice – IS 13827:1993 Improving Earthquake Resistance of Earthen Buildings – Guidelines – IS 13828:1993 Improving Earthquake Resistance of Low Strength Masonry Buildings – Guidelines – IS 13920:1993 Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces – Code of Practice – IS 13935:1993 Repair and Seismic Strengthening of Buildings – Guidelines – IS 4967:1968 Recommendations for Seismic Instrumentation for River Valley Projects – Eurocode 0: Basis of design – Eurocode1: Actions on structures – Eurocode 8 (Part 1 to 6): Earthuakes International building code, ASCE and collaboration codes

List of Codes and standards related to Earthquake Engineering Internet Sources – – – – – – Recommended Reading

Basics of Earthquake resistant Construction Performance Levels and Ranges Performance based design is a new approach used in earthquake resistance design and construction. FEMA document FEMA356 has more details These are:

Basics of Earthquake resistant Construction Performance Levels and Ranges S-1Immediate Occupancy S-2Damage Control Range S-3Life Safety S-4Limited Safety Range S-5Collapse Prevention S-6Not Considered

Basics of Earthquake resistant Construction Performance Levels and Ranges S-1 Immediate Occupancy Structure retains the pre-earthquake design strength and stiffness, and is safe to occupy. Some minor structural repairs may be appropriate but not necessary to make the building safe to occupy. S-2 Damage Control Range This range may be desirable to minimize downtime and repair time, to protect equipment that depends on the survival of the structure for its functionality, or to preserve historic features of the building when its too costly to design for the S-1 damage state. S-3Life Safety The building will retain at least some of its strength against collapse and should prevent loss of human life. However, there may be injuries and the building could potentially be damaged beyond the point of economical repair. Some business owners may desire to have a higher standard of design safety for their building. This is especially true in the case of business’ s that would suffer dramatically if business was interrupted after a seismic event. Obviously any building that collapses proposed significant risks to life safety and would not satisfy this design objective. S-4 Limited Safety Range The continuous range of damage states between the Life Safety Structural Performance Level (S-3) and the Collapse Prevention Structural Performance Level (S-5). S-5 Collapse Prevention The building experience damage to structural components that weaken it so that it retains little or no lateral resistance against collapse either in part or in full. However, it will still continue to support its own weight provided that there is no further ground motion. Aftershock activity could cause collapse, but the initial event did not bring down the building. S-6 Not Considered A building rehabilitation that does not address structural performance at all, but instead focuses entirely on non-structural hazards associated with the building such as anchoring equipment and preventing damage to tenant property and improvments.

Basics of Earthquake resistant Construction Summary -Note different collapse modes -Note different damage modes -Stiffness of Foundation and Stiffness of Structure is important -Bad foundation or soil needs to be looked at, so the structure performs as desired in an earthquake

Discuss 2 nd Assignment Book Reviews