Physical modeling of tunnels in soft ground: A review

Physical modeling has played an important role in studies related to excavation of tunnels in soft ground. A variety of modeling techniques have been developed by researchers all over the world to study ground response to tunneling. These techniques range from the two-dimensional trap door tests to the miniature tunnel boring machines that simulate the process of tunnel excavation and lining installation in a centrifuge. This paper presents a review of selected physical models that have been developed and used in soft ground tunneling research. Furthermore, this paper discusses some of the various approaches used to record soil deformation and failure mechanisms induced by tunneling. Experimental setups and sample results are presented for each technique as described by original authors. A summary of the advantages and disadvantages of each method is also presented.