Estimating

Site work

Major Components

• Erosion & Sediment Control• Fencing• Clearing and grubbing• Excavation• Backfill• Grading• Trucking

Erosion & Sediment Control

• Silt fencing– Around site perimeter on downhill side– Must be dug into ground 6 inches

• Stabilized Construction Entrance– 2” - 3” clean stone w/ fabric below

• Sediment traps/basins– 3” – 6” clean stone – Check dams

Fencing

• Does site need to be enclosed?– What are hazards?– Risk of theft– Type of fencing

Clearing and grubbing

• Must clear site– Clearing is cutting down trees• Tree size• Clearing method – chips, saw trees

– Grubbing is removing stumps• Method – dozer, excavator

• Where do stumps and tops go?

Excavation

• Need to know soil type and excavation type– Soil type will affect productivity– Excavation type will determine equipment• Dozer• Scraper• Excavator• Shovel

– Trenches may require 2 -3 pieces of equipment• Excavate, place material , backfill

Backfill

• Compaction– Type of equipment required

• Fill required– Gravel– Native material– Top soil

Grading

• Rough grading • Final grading• Stabilization– Seed and mulch– Rip rap banks– Grass mats

Trucking

– How much soil needs to be removed from the site or moved to another location on site• Does it need to be trucked?• How far – what is round trip distance?• On road or off road?

Excavation

• Quantities– Need to find volume of soil to be cut, filled• Average end area

– By contour– By cross section

– What does fill material need to be?– Trucks required• Based on size round trip• Want to keep excavators busy

Math Question:• A Backhoe weighing 8 tons is on top of a flatbed trailer and

heading east on Interstate 70 near Hays, Kansas .

The extended shovel arm is made of hardened refined steel and the approaching overpass is made of commercial-grade concrete, reinforced with 1 1/2 inch steel rebar spaced at 6 inch intervals in a criss-cross pattern layered at 1 foot vertical spacing.

Solve: When the shovel arm hits the overpass, how fast do you have to be going to slice the bridge in half?? (Assume no effect for headwind and no braking by the driver...) Extra Credit: Solve for the time and distance required for the entire rig to come to a complete stop after hitting the overpass at the speed calculated above? Yes, you can neglect friction.