Estimation of settlements due to shallow tunnels and their effects

Abstract

In this paper an empirical function for estimating settlements due to tunnels advancing in clayey soils is described. From the synthesis of the experience of many authors, a profile function was found and its validity was proved through some real cases described in the bibliography. After this, two possible ways of using the function are described and it is illustrated with a real case. One of them is the conventional deterministic method: introducing the ground parameters and the tunnel design parameters, the settlements trough and the horizontal strains are calculated. The other way is to do a probabilistic analysis helped by the calculation speed of the computers nowadays: assuming a variation in the characteristic parameters of the ground (that allways have uncertainty) all possible settlements troughs and associated horizontal strains are estimated and then, the probability of the appearence of strains over a limit at the surface is calculated.