Estimation of Confinement Loss by Using Convergence Data in Tunneling

Abstract

Obtaining a reasonable simulation of three-dimensional tunnel excavation, it is necessary to take account of the advance effect in tunneling. In the analysis of Convergence-Confinement method, the confinement loss serves to apply a portion of the confinement-removal forces in order to simulate eventual tunnel faces proximity. According to the result obtained in this study, it includes that three functions concerned the advance effect of tunnel excavation are particularly investigated; the confinement loss curve (CLC) and the tunnel convergence data are both established by using the calculation of translation method; The values of confinement loss at the working face and at the unsupported distance are acquired, and it presents a good comparison result between calculation and field measurement; and the procedure for the estimation of the confinement loss is evidently proposed, and can be used for the theoretical analysis and the numerical simulation in tunneling.