CASK_SPUDPEN Computer Program for Jack -up Leg Penetration during Preload based on ISO 19905 – 1 (2016)

CASK_SPUDPEN task is to calculate independent Jack-up rig leg penetration behaviour during preloading according to ISO Standard 19905-1 (2016) including foundation calculation methods, e.g. squeezing for sand and clay calculations – software originally created by Steve Kay  Note: the Spudcan software is CLI (command line interface based) – so text based only.


Specification Summary:

The main task objectives are to:

– Predict the final leg penetration depth

– Identify potential punch-through situations.

Methods used:

Spudcan needs a single text input file (ASCII format).This input file contains all data to do the run at run-time there are no screen commands / menu. Once the data are read in by the program no changes to the data at run-time are permitted.

(aka mudline or seabed)
Also river bed (inshore)



Normally Consolidated Clay

Cohesive soil with an undrained shear strength su in the range 0.2 to 0.35 times the in-situ vertical effective

stress (0.2 < su / σ’vo < 0.35)


Undrained shear strength

Maximul soil shear stress at yielding or at a specified maximum strain in an undrained condition



Submerged weight of all of the soil that can be preent on top of the spudcan



Soil that flows from beneath the spudcan around the sides onto the top



Soil above the plan are of the spupcan arising from sediment transport or hole sidewall collapse (note: that infill is part of backfill)



Sea floor depression which remains when a jack-up is removed from a site.





Soil and spudcan  supporting jack-upleg


Spudcan Foundation

A spudcan is the footing on a leg of a Jack-up Rig. It is designed to spread the load so that the rig does not sink too deeply into the seafloor. In plan, spudcans are generally circular, polygonal or square, with a variable cross-section. The largest spudcan used to date is about 17.5 m diameter, 5 m high and a volume of around 500 m3.



A spud-pole is the footing on a leg of (smaller) Jack-up Rigs or barges/pontoons. These are heavy poles or pipes which penetrate the seafloor and hold it in place. Unlike spudcans, these are commonly installed using kinetic energy.



Skirted Spudcan

Spudcan with a peripheral skirt



Squeezing (aka extrusion)

In this context of spudcan penetration, squeezing denotes radial soil extrusion.



Rapid, uncontrolled vertical leg moment due to soil of failure in strong soil overlying weak soil.


Installations of the spudcans by vertical loading of the soil beneath a jack-up leg spudcan with the objective of ensuring sufficient foundation capacity under assessment situations through to the time when the maxium load is applied and held.


Preload Reaction

Maximum vertical reaction under a spudcan, VL, supporting the in-water weight of the jack-up during the entire preloading operation.


Gross Bearing Capacity

Ultimate Limit State (pure V load) – at foundation depth D (or fictitious foundation depth DPT) excluding soil


surcharge (if any) between D and DPT


Net Bearing Capacity

as Gross Bearing Capacity but including soil surcharge between D and DPT





How does Spudpen work?


Get a license. Login in.

Put HASP-key in Computer

The HASP-key is like a USB-stick that you need to unlock the software for x time of license period.

Create Input File

Create txt based soil input data. Hit ENTER.

Generate Output File

Presto. Download your detailed calculated data, directly into excel or any other tool.


Note: each license term can be adjusted to your needs with a minimum of 1 year and 1 user.

Single User

1 x license
1 x HASP-key
1 year license

Multi Users (x 5)

1 x license
5 x HASP-key
1 year license

5+ or more

1+ licenses
5+ HASP-keys
1+ year licenses

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Intermediate foundations are used as anchors for floating platforms and ancillary structures, foundations for steel jackets, and to support seafloor equipment and offshore wind turbines. When installed by suction, they are an economical alternative to piling, and also may be completely removed.


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Questions / Enquiries? Please, contact us

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