Numerical investigation of stability of deep excavations supported by soil-nailing method

Deep excavation in urban areas can cause instability problems due to significant settlement at the ground surface and large movements at the excavation facing walls. One of the most popular methods used to stabilise these excavations is utilising soil-nailing method. This method has also been widely used to stabilise natural slopes and earth retaining structures. Because of the complexity involved in the mechanism of this stabilising system due to interacting effects of the soil, nails, grout and shotcrete, numerical modelling with high accuracy should be used to analyse the behaviour of the soil-nailed walls. Considering all aspects of soil-structure interaction in the present research, a large number of parametric studies are carried out to investigate the stability of deep excavations with different geometries, and the results are shown in the form of design charts and tables. Also, by employing the results of the numerical simulations and using a meta-heuristic algorithm, a simplified equation has been developed to predict the deflections of deep excavations in order to increase the safety measures during the construction and stabilisation of the excavation.