Convergence-Confinement Method for Tunnel Design

This book presents the theoretical bases and the application tools for  using the 'convergence-confinement' method which is a rational method  largely used in design engineering for tunneling. Until recently, the  stability conditions of underground works and the choice of support  methods were essentially defined on the basis of good practice or  empirical methods. The progress made, on one hand on the knowledge of  the constitutive laws of soils and rocks and, on the other hand on the  numerical modeling of the interaction between the ground and the  structures have led to the development of robust design tools for  tunnels supports. The convergence-confinement method makes it possible  to simulate the excavation of a tunnel and the installation of the  support using a simple plane strain model. The book presents the  theoretical bases of the method and its most recent developments.  Closed-form solutions for stress and displacement fields around tunnels  are provided for elastic, viscoelastic and elasto-plastic behavior of  the ground. More generally, the principles for applying the method in  numerical models are presented.