Model pile geometry, spacing, and load height to estimate dolphin strength today. Review formulas, sample data, and downloads for field planning fast and clear.
Example values for quick checking and training.
| Case | Soil | Piles | D (m) | L (m) | γ (kN/m³) | φ (deg) | Su (kPa) | h (m) | FS |
|---|---|---|---|---|---|---|---|---|---|
| A | Sand | 4 | 0.60 | 18 | 18 | 35 | — | 2.5 | 2.0 |
| B | Clay | 6 | 0.75 | 22 | — | — | 80 | 3.0 | 2.5 |
| C | Sand | 3 | 0.50 | 14 | 17 | 32 | — | 2.0 | 2.0 |
This calculator uses screening-level soil resistance distributions and integrates them over embedded length. It then applies a safety factor and an optional structural bending limit.
A piled dolphin is a compact marine structure that receives berthing and mooring forces and transfers them into the ground through one or more piles. The calculator combines geotechnical and structural checks so you can compare alternatives quickly: pile size, embedment, pile count, soil strength, and allowable movements. It supports sensitivity checks in concept design stages.
Resolve berthing and mooring loads into horizontal shear, overturning moment at the mudline, and an axial component for raked piles. For early sizing, many projects screen lateral demand around 300–2000 kN and moments that scale with fender spacing, then refine using vessel data and layout.
Axial capacity is estimated as Qult = Qb + Qs, where base resistance depends on tip area and bearing pressure, and shaft resistance depends on perimeter, embedment length, and unit skin friction. The calculator lets you apply separate factors to end bearing and skin friction so cohesive and granular profiles can be screened consistently.
Lateral capacity depends on soil reaction along the embedment. A common approach is the p–y method, where p is soil resistance per length and y is lateral deflection. In simplified form, the tool estimates an effective fixity depth and checks shear and moment against movement limits you enter.
When multiple piles act together, the dolphin’s stiffness increases but group efficiency can drop if piles are too close. As a practical rule, spacing of 3–5 pile diameters reduces overlap of soil failure zones, while raked piles improve lateral performance by converting some shear into axial load.
Structural checks confirm that the pile section can carry combined axial load and bending. For steel piles, an elastic bending check uses section modulus Z and an allowable stress fraction of yield; for concrete piles, an allowable compressive stress and reinforcement ratio govern. Corrosion allowance and reduced wall thickness can be included for marine exposure.
Serviceability often controls: excessive head deflection can misalign fenders and overstress mooring lines. Many layouts aim for lateral deflection limits of 25–75 mm at the pile head and rotation limits that keep cap and hardware in tolerance. Use the calculator to iterate until both strength and movement limits are satisfied.
For transparent results, report inputs, selected safety factors, controlling limit state, and the governing pile. Typical working-stress factors might range from 2.0–3.0 on geotechnical resistance, while structural checks follow the project’s design basis. This calculator is best for option studies before detailed modeling.
It estimates ultimate and allowable axial capacity, lateral capacity indicators, and structural checks for a piled dolphin option, using your soil, pile, and safety-factor inputs. Treat results as preliminary screening values.
Use cohesive when undrained shear strength controls, and granular when friction angle and effective stress dominate. If the profile is layered, run multiple cases and adopt the lowest governing capacity for concept sizing.
Axial capacity is the sum of end bearing and shaft resistance: Qult = Qb + Qs. Allowable axial capacity applies your selected safety factor to the ultimate value.
The tool uses simplified lateral-response assumptions to estimate fixity behavior and compare demand with resistance. For final design, confirm using p–y analysis, finite-element modeling, or project-standard marine pile software.
A practical starting point is 3–5 pile diameters center-to-center. Tighter spacing can reduce efficiency and increase deflections, while wider spacing increases cap size and hardware spans.
Yes. Enter the rake angle so the calculator resolves loads and stiffness effects more realistically. Still verify combined axial and bending interaction for the selected pile section and connection details.
Embedment length, soil strength parameters, pile diameter or width, and safety factors usually drive the result. Lateral demand and allowable deflection strongly influence the controlling limit state for berthing and mooring cases.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.