Abstract: To investigate the optimal top connector forms for partition walls and the mechanical properties of each connector form in single-tube double-track shield tunnels, a review of top connectors in existing projects is presented, and simplified calculation models for each connector form are established. The mechanical properties of these models are analyzed using theoretical methods. In addition, the validity of the simplified models and the mechanical properties, along with the applicable ranges of each connector form, are confirmed through numerical simulations. The key findings are as follows: (1) Bolts with angle steels or π steels are most effective for fully-prefabricated partition walls. (2) The simplified model provides reliable references and is suitable for the preliminary design of top connectors in partition walls. (3) The π-shaped steel connectors enhance the mechanical properties of the top connectors and are thus recommended for use in future similar projects. Moreover, the vertical hinge model proves to be reasonable and serves as a foundational reference for future research in this area.

Key words: single-tube double-track shield tunnel; prefabricated middle partition wall, top connector, connector form, mechanical performance