Abstract
Shield-driven tunneling has been playing a significant role recently as a standard method in urban tunnel construction. As the main road tunnels have to be connected with ramp tunnels efficiently, engineers have sought to develop steel-concrete composite structures using the longitudinal ribs of the steel segment as shear connectors. However, the shear connector at the connection between different types of members has hardly been studied and its stress transfer mechanism is not well understood. The authors carried out fracture experiments with scale down models for this connection, and examined the stress transfer mechanism and the shear transfer capacity carried by shear connectors and studs. A stress-transfer model for easily calculating shear transfer capacity was developed and verified through the comparison with experimental results and analytical results based on the nonlinear finite element method.