Research on the Influence of Haunch on the Hysteretic Performance of Hybrid Multi-purpose Utility Tunnel

Abstract

The hybrid multi-purpose utility tunnel (MUT), which consists of the bottom slab, the top slab, and the double-skin side walls, is popularly used due to its good structural integrity and high water resistance performance. To investigate the influence of haunch on the hysteretic performance of hybrid MUT, pseudo-static analysis was performed on four interior joints of the bottom hybrid MUT using non-linear finite element analysis models created in ABAQUS software. The height of the haunch was varied at 0mm, 100mm, 200mm, and 250mm. Results demonstrated that the failure pattern of all four joints was characterized by flexural failure at the end section of double-skin side walls. The load-carrying capacity increased with the height of haunch, but the displacement ductility decreased. (when the height of haunch is 0mm, 100mm, 200mm, and 250mm, the corresponding load-carrying capacity is 84.36kN, 95.90kN, 114.88kN and 119.87kN, the corresponding displacement ductility is 2.41, 2.18, 2.07 and 1.95). The energy dissipation capacity slightly decreases with the increase of haunch height. Moreover, a formula that correlates $\Delta P$ (load-carrying capacity increment value) and $\Delta D$ (displacement ductility increment value) with the height of haunch were fitted.