Deformation analysis in tunnels through curve clustering

Deformations in tunnels and galleries due to confinement pressures can occur continuously but also at discrete time intervals. We propose a methodology to detect discrete significant deformations in tunnels based on a probabilistic model-based curve clustering. An EM (expectation-maximization) algorithm is used to obtain the parameters of the component density functions that maximize the log-likelihood function. The estimation of the number of clusters was performed by means of the Bayesian Information Criterion (BIC).The proposed methodology was applied to the analysis of the deformations in a tunnel that has been used in the past to transport coal in an underground mine. A set of 40 profiles measured over a period of 20 months were compared. The results obtained show that deformations are not continuous but significantly high deformation episodes occur.