Mississippi Excavation and Grading

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

The standard Proctor uses 3 layers, a 5.5-lb hammer, and 12,400 ft-lb of compaction effort; the modified Proctor uses 5 layers, a 10-lb hammer, and 56,250 ft-lb, making it appropriate for higher-load applications like highways and runways.

Granular soils drain quickly and remain reasonably stable when damp, while cohesive soils become impossible to compact when saturated and take a long time to drain.

Dry soil resists particle rearrangement and won't densify without added water, while overly wet soil causes particles to float and pump away from compaction equipment.

Direct job overhead costs (e.g., traffic control, barricades, flaggers) are administrative costs tied to a specific job but not to a specific trade, whereas direct construction costs are the actual labor, material, and equipment used for construction work.

A track excavator produces higher output (50 LCY/hr vs. 29 LCY/hr) but carries significantly higher mobilization costs, making it unattractive for small, short-duration jobs where mobilization approaches 10% of total job cost.

Scrapers can dump their payload in uniformly thick layers to improve compaction productivity, whereas trucks cannot control layer thickness in the same way.

Wells, pits, and shafts 6 feet or more deep require guardrail systems, fences, barricades, or covers regardless of visibility, while general excavation edges only require fall protection when the excavation is not readily seen.

In the drying test, fissured cohesive soil develops visible cracks as it dries, while granular soil pulverizes easily into individual particles.

Imported fill allows the contractor to predict costs and compaction characteristics in advance, whereas native fill always involves unknowns regarding moisture content and compactibility.

Puddling alone achieves a maximum of about 80% of Proctor density and is least effective in cohesive soils, while mechanical compaction is required to exceed 80% density and is effective across a wider range of soil types.

Well-graded soil contains a wide variety of grain sizes that minimize air voids and compact to greater density, while poorly-graded soil has a large percentage of similarly sized particles and achieves lower density.