Backanalysis of measured movements in ageing tunnels

Abstract

The paper describes a procedure to perform backanalysis in a systematic manner in the context of ageing tunnels. Basically the input data include information on relative displacements or deformations of specific points in the lining of a tunnel exhibiting long term movements and the objective of the procedure is to identify a set of parameters that characterize the surrounding soil and the lining properties. Any damage in the infrastructure should give a change in those parameters identified. The analysis should be able to obtain useful information for the manager of the tunnel, in terms of maintenance, repair of some sections, warning in case of danger, etc. The paper presents the basic theory of parameter identification and an application to the backanalysis of a tunnel section from London Underground, where some measurements of rotation of lining segments are available.