Pipebridge refurbishment* cost effective seismic qualification by dynamic isolation

The aim of this paper is to present an appreciation of the way a refurbishment problem was tackled in the first instance, subsequently the technical merits of the seismic qualification and finally the system employed to achieve the cost benefits and set targets. The set aim was to provide a cost effective solution to the problem of qualifying an existing pipebridge to an acceptable level of seismic loading. The technical solution to the problem involved the use of a dynamic isolation system, in particular the use of elastomeric bearings to limit the likely levels of dynamic interaction of a multi component system. The practical solution to the problem of refurbishment - the cleaning, strengthening and addition of the isolation system was achieved without the necessity of providing substantial temporary works to expedite the required solution. A quality system was in use throughout to reinforce the effectiveness of the end result. (author)