1. CIEG 301: Structural Analysis
INTRODUCTION
Types of Structures
Loads

2. Corresponding Reading
Chapter 1 of textbook

3. 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

5. Building Types Majority of buildings are 2 – 20 stories
Taller office buildings
Sports arenas
Low seismic / high seismic

6. Bridge Types
Highway
Railroad
Shipping
Commuter
Pedestrian

7. Design Objectives Strength Constructability Serviceability
Maintainability
Economy
Aesthetics

8. Design Process Initial planning Determination of design alternatives
Preliminary design of alternatives
Evaluation of alternatives
Design, analysis, and redesign of selected alternative
Construction

9. Structure Types Frames Trusses Slab-on-stringer Cables Arches
Surface structures
Complex structures

10. 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

11. Support Types
Roller
Pin
Fixed

12. 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

13. 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

14. 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

15. Load Transfer and Load Distribution
Consider a typical building framing plan
Work from top down
Determine tributary widths and tributary areas as appropriate