In tunnel construction, the excavation method usually suitable for soft soil is ().

According to the method of tunnel excavation, it can be divided into: (1) drilling and blasting method (also known as mining method), which is a tunnel built in the stratum by excavation and blasting. Firstly, the underground space is formed by excavation or drilling and blasting on the tunnel excavation surface, and then the surrounding rock is supported according to its stability and use requirements. (2) The shield tunnel is a tunnel built with a shield machine. Generally, external excavation is carried out to control the surrounding rock and tunnel surface from collapsing, and slagging is carried out while advancing, and segment lining is assembled in the machine. One-step cross-section molding is often used in soft soil stratum, and the cross-section of tunnel molding is generally round. (3) TBM tunneling is a tunnel built by mechanical rock breaking, slag tapping, support and continuous operation. According to the cutting process of roadheader on the working face, it can be divided into full-face roadheader and partial-face roadheader. According to the principle of rock breaking, it can be divided into rolling (circular hob) tunneling and milling roadheader. Rock roadway from medium hard rock to hard rock generally adopts rolling excavation, while milling roadheader is suitable for coal seam and soft rock. (4) Rock crusher tunnels and tunnels excavated by hard rock crusher are generally excavated by a single-arm spherical drilling rig, which can be used to excavate rock tunnels with any cross-section shape.