Pressure anisotropy on twin tunnel linings induced by a transverse gallery construction using time-dependent constitutive models

Resumo

The increasing construction of twin tunnels demands a comprehensive understanding of their interaction with transverse galleries and the surrounding rock mass. This study conducts a 3D finite element analysis of the junction between deep twin tunnels and a transverse gallery, incorporating time-dependent effects such as rock mass creep, concrete creep, and shrinkage. The model is verified against existing numerical results, confirming its reliability in estimating internal forces in the lining. The influence of different rock mass friction angles on pressure distributions is investigated, revealing that higher friction angles significantly reduce lining pressures, particularly at the end of tunnel construction. The results indicate pronounced anisotropy in pressures, influenced by the properties of the lining and the rock mass, and peak pressures are observed at the lateral sides of the walls. Additionally, viscoelastic linings exhibit increased long-term stress redistribution, emphasizing the role of rheological behavior in tunnel performance. These findings offer valuable insights for the design and reinforcement of tunnel–gallery intersections. The study reinforces the importance of 3D modeling and time-dependent behavior in the safe and accurate design of tunnel–gallery intersections.