The Effect of Loading Type on the Amount of Effect of Loading on the Surface Settlement During Forepoling Tunnel Excavation in Different Geotechnical Conditions

Abstract Among the important phenomena caused by tunnel excavations, the settlements on the ground surface can be mentioned, which are particularly important for shallow tunnels excavated in urban areas, and especially when passing under residential areas of cities. Numerous methods such as mathematical (numerical and analytical) ones can be used to predict surface settlement. This study was conducted aimed at using modern techniques such as artificial neural networks to analyze the parameters affecting the occurrence of surface settlement during forepoling tunnel excavation. Tabriz Subway project is a good opportunity to examine the effect of forepoling tunnel excavation the surface settlement in a granular soil with average groundwater level offers. None of the performance parameters (such as the features of the forepoling protective umbrella) and the environmental features (such as the geological effects and tunnel geology) establish a unique relationship with the surface settlement, but several factors together do so. In this study, the forpolling tunnel was modeled using Plaxis software and analyzed in various geotechnical conditions (drained, partially saturated and saturated) under static and dynamic loading. Finally, the values of the surface settlements were examined.