Structural Integrity Control of Ageing Offshore Structures: Repairing and Strengthening With Grouted Connections

Structural integrity control (SIC) is an increasingly important element of offshore structures. Not only is it used in newly built and existing offshore structures (e.g. oil and gas (O&G) production & process facilities (P&PFs), wind turbine installations, etc.), but SIC is also essential for ageing offshore platforms which are subjected to an extension of their design service life. In these cases, SIC programs must be performed to assess the platforms. If any significant changes in structural integrity (SI) are discovered, then it is essential to implement an appropriate strengthening, modification and/or repair (SMR) plan. Currently, welded and grouted repairs are mostly used for SMR. Although a welded repair may typically restore a structure to its initial condition, if the damage is due to fatigue loading and welded repairs have been carried out, then historical evidence reveals that there is a high potential for the damage to reappear over time. On the other hand, mechanical connections are significantly heavier than grouted connections. Consequently, grouted repairs are widely used to provide additional strength, for instance, to handle situations such as preventing propagation of a dent or buckle, sleeved repairs, leg strengthening, clamped repair for load transfer, leak sealing and plugging, etc. This manuscript examines current developments in grouted connections and their comparative pros and cons in relation to welded or mechanical connections. It also provides recommendations for future research requirements to further develop SMR with grouted connections.Copyright © 2013 by ASME