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ECIV 320 Structural Analysis I. Structure. A system of connected parts used to support load. A structure is designed to serve a specific function for public use. From 2500 years old…. … to present…. … and future. Engineers build structures. Savannah GA. But things don’t always work….
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ECIV 320 Structural Analysis I Structure A system of connected parts used to support load A structure is designed to serve a specific function for public use
Engineers build structures Savannah GA
Failures Northridge 1994 Parking garage at California State University
Failures San Fernando Mexico City
Collapsed Cypress section of Interstate 880 the 1989 Loma Prieta (California)
1989, Loma Prieta Earthquake, 7.1R San Francisco-Oakland Bay Bridge
Northridge earthquake apartment building in Northridge Soft Story Effects
Kobe 1995 Collapsed first and second stories
Kobe 1995 Leaning office building Collapsed walkway
Collapse of Freeway in 1989 Loma Prieta, CA Earthquake (7.1R)
LIQUEFACTION-DIFFERENTIAL SETTLEMENTS Niigata, Japan.June 16, 1964, 7.4
GROUND DEFORMATION-DIFFERENTIAL SETTLING Earthquake of July 29, 1967, Caracas, Venezuela.
Factors in Design • Safety • Aesthetics • Serviceability • Environment • Economy
QUESTION What is the optimumsize of a structural element in a structure that will support the required loads?
GENERAL DESIGN PROCEDURES Problem Definition Service Functions Location Surface & Subsurface Conditions Infrastructure Environmental Impact etc • Constraints • Material Availability • Zoning Requirements • Construction Expertise ...
General Design Procedures Geometric/Architectural Design ………. Altern. 1 Altern. 2 Altern. 3 Altern. n Final Layout Floorplans Elevations etc
General Design Procedures Preliminary Structural Design ………. Altern. 1 Altern. 2 Altern. 3 Altern. n Prliminary Design: Location and arrangement of load bearing elements, columns, beams, footings etc., Sizing of structural elements for safety and serviceability Architectural Constraints - Simplicity & Duplication - Fabrication & Construction Procedures Economy: Add preliminary $ value to each design Select Alternative for Final Design
General Design Procedures FINAL DESIGN Sizing of Members Design of Details Design Drawings* (Blueprints) Bill of Materials Total Cost *Design Drawings Complete and Easy to Read AISC: Detailing for Steel Construction Engineering for Steel Construction
Define External Loads Estimate/Assume Initial Size of Structural Elements Calculate Self Weight Structural Analysis Select New Sizes Check Design (Codes & Specs) Safe Functional Economic NO YES O.K. Preliminary/Final Design
OBJECTIVE OF THIS CLASS • Safety • Aesthetics • Serviceability • Environment • Economy
OBJECTIVE OF THIS CLASS We will learn the concepts, methods and procedures that will allow us to estimate the “demand” imposed on structural members by external loads