Abstract The existing tunnels deform inevitably due to the excavation of a new tunnel nearby in the urban underground engineering construction. Correctly analyzing and predicting the deformation of the existing tunnel has been an important issue in underground engineering. Peck equation is one of the most popular used methods to predict the soft ground movement induced by the shallow tunneling. 23 sets of measured data from 10 projects in Beijing were found to fit well with Peck equation. The ground loss ratios fit by Peck equation are from 0.116% to 1.183%,and the width parameters of the settlement trough are from 0.93 to 6.76. The effects of the construction method of new tunnels,the auxiliary construction method of new tunnels,the burial depths of both the new tunnels and the existing tunnels,the flexural rigidity of the existing tunnels,the distance between two new tunnels and the position of the deformation joints of the existing tunnels on the fitting parameters were analyzed. Empirical formulae of fitting parameters were thus derived. Combining Peck equation with the empirical formulae of parameters,a simple and convenient method of prediction on the deformation of the exiting tunnels in Beijing area was obtained. The validity of the method was confirmed in an engineering case study.
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Received: 31 July 2013
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