Structure reasonableness of segmental joint shear keys on immersed tunnel

In order to optimize the structure of shear keys and improve their stress performance, the 3-D numerical simulation software was adopted. In addition, the mechanical characteristics of segmental joint shear keys on immersed tunnel were analysed and these results were compared to the mechanical characteristics and failure conditions in large scale model tests. The result that local compression stress on shear key tips and local tension stress on the link part between shear keys and segments were large was obtained. Furthermore, based on these mechanical characteristics, the advice that setting up tensile reinforcement on the link part was put forward. Besides, three structure changes on shear key tips were proposed and they were studied by local 3-D numerical simulations, whose results were compared to those of engineering prototype. The results show that, comparing to the prototype, increasing horizontal inclination of shear keys has benefits to the stress distribution of shear keys, but its effect is not so notable. The circular angle design can improve the stress performance of shear keys significantly, and its local stress can decrease 27.2% than that of engineering prototype. However, the concentration of chamfer angle design has no advantage to the stress performance of shear keys, which should be avoided. ©, 2015, Editorial Department of Journal of Chang'an University (Natural Science Edition). All right reserved.