Determination of longitudinal convergence profile considering effect of soil strength parameters

To investigate the stability of ground surrounding shallow tunnel, an important step is to study the medium using the stress-strength method. The method includes the longitudinal convergence along tunnel. The studies done up to now are concentrated on the deep tunnels in the form of presenting a longitudinal deformation profile (LDP). It expresses relation for unsupported tunnel wall/crown by various researchers in terms of distance from excavation face along the tunnel. Of course, the effect of soil strength parameters is not considered in the relations yet. It is attempted in the current research work to propose a new concept of Longitudinal Convergence Profile (LCP) as alternative to Longitudinal Deformation Profile LDP. Then, a series of 3-dimensional analyses are conducted on a sample with conventional stratified environment observed in metropolitans. Finally, to include the effect of soil strength parameters, i.e., modulus of elasticity, cohesion and internal friction angle of soil on the LCP, a new set of relations is suggested.