Maintenance of rock caverns and Tunnels

Abstract

Maintenance of subsurface facilities in rock excavations has been from the economic point of view of growing significance during the last few years. The purpose of this project was to elucidate presumptions for maintenance planning and to elaborate a proposal regarding the way in which maintenance planning could be established in different types of rock facilities. Furthermore, the intention was to analyse the present experienced or required maintenance and to find a system that enables the gathered information to be codified, classified, arranged and stored. Such a system makes the stored information easily available if needed as an aid in connection with designing, budgeting, contracting or experience recapturing. Among the investigations in this project was one case studied, selected from an inquiry among 34 owners of over 442 rock facilities and analysis of the factors of essential importance affecting maintenance. They enabled the exploration of valuation criteria, which are the basis for the proposed maintenance planning system. According to inquiries there are in general three main reasons for estimating the necessity of maintenance; security of personnel, avoidance of operation interruptions and reduction of maintenance costs. However, the complexity of maintenance problems is due even to deficient knowledge and incompleteness of documentation regarding the construction period and present condition. The most important conclusion achieved by this project is that the claims for utmost economy and security of a particular rock facility is based on a systematized maintenance based on rational planning, specified instructions and supervision. Systematized maintenance may in the future be a valuable resource of experience which can be applied by rock structure designers. (TRRL)