Formula used
Rectangular volume = Length × Width × (Required depth − Existing depth) Average-end-area volume = ((Area 1 + Area 2) ÷ 2) × Section length × Section count Total in-situ volume = Design volume + Allowances + Contingency Disposal volume = In-situ volume × Bulking factor Settled volume = Disposal volume × (1 − Consolidation percentage) Wet mass = In-situ volume × Bulk density Dry solids mass = Wet mass × (1 − Moisture percentage) Trips = Ceiling(Disposal volume ÷ Effective load) Cycle time = Loading + Unloading + Maneuvering + Loaded travel + Return travel Daily production = Trips per day × Effective load Capacity balance = Effective remaining capacity − Settled volume Total cost = Direct costs + Overhead + Taxes + Cost contingency Emissions = Diesel use × Diesel factor + Electricity use × Grid factor
How to use this calculator
- Enter project details and choose consistent input units.
- Select a volume method and enter dredging geometry.
- Set allowances, material properties, and bulking behavior.
- Choose transport equipment and enter operating assumptions.
- Enter disposal-site capacity and treatment requirements.
- Complete the screening checklist and permit status.
- Add project costs, fuel factors, and comparison alternatives.
- Select Calculate disposal plan and review every warning.
Example data
| Input | Example value | Purpose |
|---|---|---|
| Dredge dimensions | 500 m × 40 m × 3 m cut | Defines the base excavation volume. |
| Bulking factor | 1.15 | Expands in-situ volume after disturbance. |
| Barge capacity | 1,200 m³ at 90% | Sets the effective load per trip. |
| Haul distance | 18 km one way | Controls travel time, fuel, and cost. |
| Site capacity | 120,000 m³ total | Checks available placement space. |
| Moisture content | 45% initial, 25% target | Estimates water removal and final volume. |
Frequently asked questions
What is dredged material disposal volume?
It is the volume requiring placement after dredging. It often differs from surveyed in-situ volume. Bulking and consolidation strongly affect final capacity needs.
Why is a bulking factor required?
Dredged sediment usually expands after excavation and handling. Voids and entrained water increase transported volume. Use project-specific testing whenever reliable data exists.
Does this calculator approve a disposal site?
No. It only provides planning estimates and screening prompts. Regulators and qualified professionals make suitability decisions.
Which transport modes are supported?
The form supports hopper dredges, barges, pipelines, trucks, rail, conveyors, and combined systems. Cycle transport uses capacity and travel time. Pipelines use pumping throughput.
How is disposal-site capacity checked?
The calculator subtracts used and reserved capacity. It then applies placement efficiency. Settled volume is compared with effective remaining capacity.
How are project days estimated?
Daily production includes operating hours, efficiency, and weather downtime. Cycle transport also includes loading and unloading. Actual schedules may require seasonal work windows.
How is dewatering estimated?
Dry solids mass remains constant during water removal. Final wet mass depends on target moisture. The difference estimates water requiring removal.
What costs should be included?
Include dredging, transport, placement, treatment, testing, monitoring, labor, overhead, taxes, and contingency. Add local costs not shown. Review every unit rate before budgeting.
Can beneficial use be compared?
Yes. Each alternative accepts a beneficial-use share. The comparison also considers cost, capacity, distance, and environmental status.
How accurate are the emissions results?
They depend on entered fuel and electricity factors. Equipment load changes can be significant. Use measured consumption for stronger estimates.
What should be verified before construction?
Verify bathymetry, sediment characterization, equipment production, disposal authorization, permits, monitoring requirements, and cost quotations. Confirm assumptions with responsible specialists. Document every revision.