A enda Dee water Foundations used Mala sia Types of Deepwater Foundations Types of Deepwater Foundation Accessories – Diary of a Driven/Suction Pile (Fabrication to Installation) Pile Design Q&A
Deepwater Foundations used in Malaysia
Types of Deepwater Foundations
Suction Anchor Piles
Driven Piles
Torpedo Piles
SEPLA Anchors
Deepwater Foundation Accessories
Mudmats
Pile Guide Frame
ILT
What are the foundation facing ? Seismicity
Continental Shelf
What are the foundation facing ?
Diary of a Driven Pile
(Fabrication)
Note: Suction Anchor Pile fabrication same concept but at larger scale!
Diary of A Driven Pile (Loadout to Installation)
Prepare Resume !!! ☺
Diary of A Suction Pile (Loadout to Installation)
Pum out entra ed water by suction
Pile Design Pile Design Codes API RP 2T (Tension Leg Platforms) , Shell DEP API RP 2SK (Floating Structures) , Shell DEP
Pile Design e ec on o o parame ers Eg Driven Pile in Clay • • • • • • • •
Submerged Unit Weight of Soil (kN/m3) Undisturbed Undrained Shear Strength (kPa) Remoulded Undrained Shear Strength (kPa) Soil sensitivity data 50% Strain factor Є50 (%) Creep data to define loss of strength under sustained loads Cyclic degradation data to define loss of strength under cyclic loading -
Pile Installation Tolerances Esta
s Des gn Loa
ases
F
Design for Pile Penetration
e es gn w e ase on max mum oa s mpose y t e var ous oa ng con t ons as eterm ne y moor ng analysis. Limit equilibrium analysis and beam-column analysis to verify the integrity of pile and soil. Resulted in load deflection response with consideration of non-linear behavior o of soil response lateral (p-y) and axial T-z. Pile group . . . a.
b.Reduction of axial capacity – strain softening of soil - effect of large deflections (gapping) - critical delfections - Soil disturbance during pile installation -Soil set-up/Hydrate
Geotechnical Investigation Survey
idea of geologic features, identify geohazards in the project site egshallow faults, earthquakes, steep slopes and pockmarks establish the uniformity (or the lack thereof) of soil formation
Geophys ical investigation tools & now AUVs.
Requirements for site investigations should be guided primarily by the type of platform to be installed, the availability and quality of data from prior site surveys, and the consequences that would result from a partial or complete foundation failure.
Geotechnical Investigation Survey Seabed Drilling vs Surface Drilling
Seabed Mode vs Downhole Mode
Geotechnical Investigation Survey Typical Hazards/Risks (Deepwater Site Investigation) •Presence of Shallow Gas Hazard •Effect of Hydrate Dissociation •Excessive Seabed Slope for seabed mode •Seabed Current • •Stress relief during recovery of the sample -cause expansion and disturbance
•Slope instability •Loss of Position •Incorrect Positioning ! •Features such as pockmarks, scars, sand waves •etc
Geotechnical Vessel & Equipment Water Depth and Penetration Capabilities of -Drilling, Sampling and Coring Systems -In-Situ Testing Systems
g s n m i l e t m s a y S S , g n g i n i r l o l i r C D &
g n i t s e T s u m i t S s y n S I
‐
Equipment Description
Maximum Water Depth (m)*
Penetration (m)*
Drill mode borings from vessel
Unlimited **
Unlimited **
Rock Corer (Seabed Unit)
200m
2m to 6m **
Piston Corer
Unlimited **
3m to 30m
Box Corer
Unlimited **
0.3m to 0.5m
Seabed Push in Sampler
250m
1m to 2m
Grab Sampler (mechanical)
Unlimited **
0.1m to 0.5m
Wireline Pressure Coring
Unlimited **
Unlimited **
Deck or frame‐ operated Penetration Tests
20m
2m to 60m
Seabed wheeldrive Penetration Tests
500m to 3000m
2m to 60m
Drilling downhole mode Penetration Tests
Unlimited **
Unlimited **
Seabed Vane Test
250m to 2500m
5m to 25m
note: General ‐ Ultra‐ deep site investigation (>2000m water depth) in development (?) * Figures should be used for genreal guidance only l t i T e l i F
** Water depth is limited by the deployment winch and handling capabilities
