Abstract Precast reinforced concrete segmental linings are frequently used in modern tunneling. In these linings, the longitudinal joints typically have a reduced contact cross‐section and thus often govern the design, particularly in tunnels under high hydrostatic pressure or crossing squeezing or swelling ground with correspondingly high circumferential compressive forces. Reinforced concrete segments with substantial confining reinforcement in the load dispersion zone next to the joints are a viable option to resist such loads. However, this solution has not been widely used in tunneling yet, mainly due to limited coverage by existing guidelines and lack of experimental validation. The present article addresses this knowledge gap. It (i) presents the results of an experimental campaign investigating the structural behavior of tunnel lining segments with longitudinal joints in nine reinforced concrete specimens with pronounced passive confinement, (ii) proposes a modeling approach based on a bespoke stress field solution for the design of longitudinal joints allowing the entire load path to be followed and (iii) extends this stress field to cover the effect of guiding rod grooves. The results of the experimental campaign provide valuable insight into the structural behavior of the longitudinal joints. They confirm that substantial passive confinement can be activated and can contribute to the load‐bearing capacity, but also highlight that the unconfined zone of the segments can become governing for high compressive forces resulting from high confining stresses and wide longitudinal joints. The comparison of the experimental data and the proposed modeling approach shows very good agreement. Thus, it can be recommended as a valid basis for design.
Morger et al. (Wed,) studied this question.