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Grouted Offshore Piles For Alternating Loadings

Objective


Project's actual outcome:
- jet-grouting technology to reduce pile length and settlements;
- documented increases in pile capacity in sand over time;
- constitutive model for jet-grouted soil;
-improved jet-grouting technology.

Of these outcomes, numbers 1, 3 and 4 are proprietary results that will be employed to increase competitiveness of the commercial partners in the world market. Result 2 is of general scientific/engineering importance, and has been released to the technical community.
The European offshore industry is seeking to reduce piling costs; innovative foundation system are required. This research provides enabling technology to increase pile capacity for both static and alternating loads: install jet grouted bulb at pile tip to increase end bearing and take advantage of increases in shaft resistance with time.
These solutions will reduce pile length and foundation costs. Offshore structures are subject to environmental loads which induce alternating compression and tension forces at the foundation level. Foundation piles resist applied loads by friction along the shaft and end bearing of the tip on underlying soils. This project addresses both issues. Current design methods underestimate shaft friction in sand, neglecting long term increases in capacity. End bearing can be increased by enhancing existing onshore technology, Jet Grouting, to improve soil below the pile tip. Pre competitive work required to develop these concepts includes: o research on increase of shaft friction over time; o basic geotechnical properties of jet grouted soils; o modifications/extensions of existing jet grouting technology; o onshore field test to prove effectiveness.
Europe has a strong onshore soil improvement industry. After Japan, it is considered to be the world leader. The offshore sector is alsc significant, including national petroleum companies and major marine construction contractors. The objective of this project is to create synergy between these groups, transferring onshore technology the tc marine environment. These methods will open new markets for European Jet Grouters, increase Europe's competitiveness in offshore construction, and allow development of marginal hydrocarbon reserves.
This project responds to the scope and objectives of MAST III, by optimising pile foundations subject to alternating loadings (research area C.1.5). The work directly addresses the MAST Theme IV, "Technological Opportunities" by developing multisectorial industrial applications with clear economic benefits.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

D'APPOLONIA SPA
Address
Via San Nazaro 19
Genova
Italy

Participants (2)

IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
United Kingdom
Address
Imperial College Road, Exhibition Road
SW7 2BU London
SOLETANCHE BACHY FRANCE SA
France
Address
6,Rue De Watford 6
92000 Nanterre