Alabama Sitework Contractor

T-99 compacts the mold in three layers with a 5.5-lb hammer (25 blows per layer) for 12,400 ft-lb of effort and is specified under building slabs, sidewalks and utility trenches in grassy areas, while T-180 uses five layers with a 10-lb hammer for 56,250 ft-lb and is used for higher design loads such as federal highways, airport runways and nuclear power plants.

A track backhoe can revolve a full 360 degrees with the cab turning on the turntable and a small ¾-yard trackhoe has a minimum effective cycle time of about 15 seconds (large ones 30–40 seconds), whereas a wheeled backhoe rotates only 180 degrees and has a minimum effective cycle time of about 10 seconds.

The plan view is a bird's-eye overhead view showing the layout of the work area, while the profile view is a horizontal cut-away (cross-section) along the alignment showing elevations, grades and depths.

A payment bond guarantees that all bills for labor, equipment and materials are paid and that liens against the owner's property are discharged, while a bid bond guarantees the bidder will enter into the contract and furnish performance and payment bonds — with default costing either the full bid bond amount or the difference between the low and second-low bid, whichever is smaller.

Adding 10 percent markup to $90,000 hard costs yields $99,000 and recovers only $9,000, whereas a true 10 percent overhead margin requires dividing hard costs by (1.0 minus the desired margin): $90,000 ÷ 0.90 = $100,000.

Bank volume is the in-place excavated volume (length × width × depth ÷ 27), while loose volume is that bank volume increased by the swell factor and is the figure used for haul-off truck loads — using bank volume to size loads under-counts the number of loads.

Puddling alone can sometimes reach only up to 80 percent of Proctor density and is least effective in cohesive soils such as silt and clay (best in sand, gravel and desert-type soils), so mechanical compaction must be added to exceed 80 percent.

Soils under building slabs and sidewalks are usually specified at 90 percent of maximum dry density for cohesive soils versus 95 percent for non-cohesive soils.

Per Subpart P Appendix A(b), Type B cohesive soil has an unconfined compressive strength greater than 0.5 tsf (48 kPa) but less than 1.5 tsf (144 kPa), while Type C is 0.5 tsf (48 kPa) or less — so a soil at exactly 0.5 tsf is Type C.

Directional drilling is practical for tunneling up to 2,200 feet with pipe 16 to 36 inches in diameter, while directional boring with a pneumatic mole typically handles pipe only up to 6 inches in diameter for 50 to 150 feet.

Under §1926.501(b)(7)(ii) wells, pits and shafts 6 feet or more deep require guardrail systems, fences, barricades or covers regardless of visibility, while under (b)(7)(i) protection at general excavation edges is required only when the excavation is not readily seen.

An escalation allowance covers expected increases in labor, material and equipment costs between bid submission and completion (important in high inflation), while a contingency allowance covers possible problems from uncertain conditions such as missing boring logs and cushions idle equipment rental costs.

Average cut-to-fill haul distance drives equipment choice: dozers for short hauls, self-loading scrapers for longer hauls, loaders and trucks for long-distance hauling, and graders only for very slight cuts and fills.