1. Structure of a Building
STRUCTURAL ENGINEERING
Structure of a Building
The primary function of a building structure is to support and transmit the loads and forces to the ground.
“Tracing the Loads” or
“Chasing the Loads”

2. Characteristics of a Structure
Stability – needed to maintain shape. The structure is dependent upon balanced forces and equilibrium
Strength - ability of the structure to withstand the applied forces, usually includes a “factor of safety”
Economic Value – includes choices made about the design, materials, and function of the structure

3. Forces and Loads Design Loads Dead Loads (DL) –fixed loads
building materials/components and the weight of structural components
Live Loads (LL) –transient and moving loads
Occupancy loads and furnishing loads (bldg usage)
Snow loads
Construction loads
Live Load maybe variable during structures lifetime
Building codes specify these loads for floor and roof loadings

4. Design Loads Snow Live Load Roof Materials & Structure Dead Load
Walls, Floors,
Materials &Structure
Dead Load
Occupants, Moveable
Fixtures & Furniture
Live Load

5. Design Loads (continued)
WIND
Wind Load (WL) –
Resulting loads yields
Lateral load on walls
Downward and upward pressure on roofs
Pressure
Uplift
Suction

6. Design Loads (continued)
Earthquake Loads (EQ)
Seismic load based on building mass , type and configuration.
Vertical and lateral forces (dynamic)
Building codes can simplify loading
Epicenter
Seismic Forces at Base of Building
Hypocenter

7. Loads & Load Paths Snow or roof load for non-snow areas
Use and occupancy
Self weight of structure
Ground reaction