Transcript ADVANCED STEEL DESIGN - University of Delaware

CIEG 301:
Structural Analysis
INTRODUCTION
Types of Structures
Loads
Corresponding Reading
 Chapter 1 of textbook
What Do Structural
Engineers Do?
 Analyze and design new structures
 Investigate the capacity and serviceability
of existing structures
 Develop retrofit methods for existing
structures with inadequate capacity
 Forensic investigations
 Research and development
Building Types




Majority of buildings are 2 – 20 stories
Taller office buildings
Sports arenas
Low seismic / high seismic
Bridge Types
 Highway
 Railroad
 Shipping
 Commuter
 Pedestrian
Design Objectives






Strength
Constructability
Serviceability
Maintainability
Economy
Aesthetics
Design Process





Initial planning
Determination of design alternatives
Preliminary design of alternatives
Evaluation of alternatives
Design, analysis, and redesign of
selected alternative
 Construction
Structure Types







Frames
Trusses
Slab-on-stringer
Cables
Arches
Surface structures
Complex structures
Member Types
 Each of these structures is comprised of hundreds or thousands of
members
 Some common member types
 Beams / Girders / stringers - flexural members – load applied
perpendicular to length, moment and shear are primary forces
 Columns – compression members – load applied parallel to
length at member ends, axial force dominates
 Beam-columns
 Tension members
 Compression members
 Tie rods – tension force only
 Arches
 Common connection types
 Pinned
 Fixed
Support Types
 Roller
 Pin
 Fixed
How do we design
structures?
 Conceptual Consideration:
 Determine forces (and deflections)
 Our focus for the semester
 Determine capacity (and deflection limits)
 Focus in Structural Design next semester
 Require capacity is greater than forces
 Legal Considerations
 For most structures, owner specifies code
 e.g., AISC, PCI, AASHTO, AREMA
Loads


Forces in a structure are a result of loads
What types of loads do we need to consider in a civil engineering
structure:
 Dead load:
 Live load: building occupants, truck traffic
 Environmental loads:
 Snow load
 Rain load
 Wind load
 Seismic load
 Bridge specific
 Temperature loads (expansion and contraction of restrained
members)
 Impact
 Breaking force
 Collisions (water and land traffic)
 Water loads
 Ice
Dead Loads
 Self-weight of:
 Structural components (e.g., beams, slabs)
 Non-structural components (e.g., decorative
façade, plywood subfloor, ceiling tiles,
asphalt wearing surface)
 Useful Tables in textbook:
 Table 1-2: Densities of Typical Materials
 Table 1-3: Dead Loads of Typical Materials
Load Transfer and
Load Distribution
 Consider a typical building framing plan
 Work from top down
 Determine tributary widths and tributary
areas as appropriate