Soil Reinforcement in Soft Ground Tunneling

摘要

A new technique of reinforcing earth masses around tunnels, known as the spiling reinforcement technique, is illustrated. The system consists of a series of radially installed reinforcing spiles spaced between 2 and 5 ft. with an angle of approximately 30 degrees to the tunnel axis. The spiles are formed by inserting 1-1.5 in. diameter rebars into the holes with subsequent grout. This report presents the results of the preliminary investigation of the spiling reinforcement system in soft ground tunneling. It includes the development of the analytical method of analysis, the major findings from the parametric study, and the development of the centriguge model testing program. The analytical method of analysis includes the development of a computer finite element program with the generalized plane strain approach. The model testing program includes the modeling process of tunneling and spiling reinforcement, and the simulation of the excavation procedure in flight.