1. Steel Construction

2. 3 components 1) Advanced Planning
Divisioning – dividing structure into units used to schedule fabrication and delivery
Determined by order in which structure is erected
Joint effort between fabricator and erection manager
Must check size and weight of members against plant capacity, transportation size, wt limits, erection equipment capacity

3. 3 components 2) Fabrication 3) Delivery
Shop drawings, steel type, built up or rolled section, connection method, camber
3) Delivery

4. Field Operations Receiving and unloading
Sorting – shake out – id members with code
By size or by placement on structure
Want all material for a unit in one place
Inspecting
Welds, rust, warped or torqued
Storing – store off ground, protect from dirt, grease, corrosion
Large members stored on truck until erection
Need a large enough storage area
Yarding – storing in a temp area and then moving to erection area
Erecting

5. Field Operations Must be careful unloading steel
Can damage surface coating, bend or torque members
Use double slings to avoid bending members
Must inspect for damage and conformance to shop drawings and tolerances
T14-1

6. Structural Steel Types of Steel
A36 carbon structural steel – most common
A572 High Strength – Low Alloy Structural Steel
A 588 Corrosion resistant High Strength – Low Alloy Structural Steel
Weathering steel – develops protective coating – no painting required

7. Structural Steel Camber and sweep
Camber – looks like frown allows for beam to return to level position once load is applied
Sweep – curve in beam

8. Structural Steel Standard Rolled Shapes Built up members
F 14-2, T 14-2
Built up members
F14-3
Used when common rolled shape is not available
Open web joists and joist girders, F14-5&6
Light weight, strong
Used extensively on roofs and floors
Castellated beams – F14-7

9. Erection Usual process uses three crews
Raising crew – lifts member into position and temp bolts it into position (safely)
OSHA regs – structural integrity – ability of structure to safely stand during erection
Safety regs - erection floor cannot be more than 8 floors above highest completed permanent floor, Not more than 4 floors of unfinished connections above highest permanently secured floor
Fitting crew – brings member into proper alignment and tightens enough bolts to hold it in place
Fastening crew – final connections

10. Lifting Equipment Cranes, tower cranes
Small jobs may see F 14-9 ( old stuff)

11. Alignment of Steel
Within tolerances of AISC Code of Standard of Practice
Vertical or plumb error +/- 1 unit in 500 units of height
Outside columns cannot be more than 1” towards or 2” away from building line in 20 stories
Minimum clearance between members
Coping or blocking – notching beams to provide clearance when connecting beams to columns
Electrical and plumbing notches need to be designed

12. Alignment of Steel Guys Erection of Steel Joists
Cables used to align members
Do not overstress
Erection of Steel Joists
Require lateral bracing
Cannot release joist from crane until braced

13. Field Connections Fastening systems Bolting
Two types of bolt systems
Interference-body or interference-fit bolts
Oversized bolt driven into hole – holds bolt in place while tightened
Tension Control or tension set bolts
Bolt stem breaks when specified torque hit
In both cases need to make sure that bolts are tightened to specified torque
F14-11, 14-12
Riveting – not used much today

14. Field Connections Fastening systems Welding
All welders should be certified by American Welding Society
F standard welding symbols
Welds must be tested & inspected for quality
Visual – quickest must be highly trained
Destructive – used when questionable quality
radiographic, ultrasonic provide image of weld
magnetic particle, liquid penetrant inspection - show flaws

15. Safety Hard hats, gloves
Eye protection for welders, cutters, chipping ops
Harnesses if off ground level
And scaffolding
Over 25’ – safety nets
Tag lines on all hoisted beams to handle swing
Surfaces of beams must be dry and suitable for walking