11/22/2017
Soil Nailing (2)
Bench Down and Excavation (1)
• Bars installed at a slight downward inclination • Solid bars ▫ Usually installed into pre- drilled holes. ▫ Grouted into place using a separate grout line, • Hollow bars ▫ Drilled and grouted simultaneously ▫ Sacrificial drill bit used • Kinetic method ▫ Relatively short bars fired into soil slopes
• Method used when soil is unstable • Cave in is likely to occur • 20 feet maximum excavation depth • Two Types: ▫ Simple One Bench ▫ Multiple Multiple Benches
Bench Down and Excavation (2)
Excavation Methods
Purpose
Vertical
-Large urban sites -Many layers of occupancy -All layers exposed in vertical sections
Superstructures
Horizontal
-Shallow sites -Two or Threelayers of occupancy Can combine Vertical and Horizontal Excavation
Step Trenching
-Deep digging required -Opening large area on the surface -Smaller in size it moves downwards
Cofferdams
-Deep excavation where sides seem to collapse -Case of waterlogged sites
Superstructures
Wood Frames
Soil Nailing (1)
•Stack Framing •Balloon Framing
Structural Steel
•Bar Joists •Precast Planks •Staggered Truss with Precast Planks •Composite Deck Precast Concrete
• Technique to treat unstable natural soil slopes • Allows over steepening of new or existing soil slopes. • Components: ▫ Relatively slender reinforcing elements ▫ Solid or hollow bars are also available ▫ Installation techniques vary
•All Precast •Tilt up and Bar Joists •CMU Precast and Bar Joists •Sigma Stud with Precast Planks
Pre Engineered
•Metal Building •Structure •EPICOR •Worthington®
Cast in Place
•Mild Steel Reinforcement •Pre Tension •Lift Plate System
Thermasteel®
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