A novel non-planar interlocking element for tubular structures

In this paper, a novel non-planar interlocking element is developed, which can be used to construct cylindrical structures. The proposed element has a symmetrical geometry with six curved side surfaces to be interlocked with adjacent elements. A tubular structure can be constructed by assembling a number of identical non-planar elements, and the movement of each element is naturally restricted in all directions. To investigate the performance of the proposed system, a 3D finite element model is established to simulate the dynamic response of a concrete tunnel assembled using the new non-planar elements. Compared to the monolithic concrete tunnel and the tunnel constructed of normal concrete segments, the interlocking tunnel has shown a lower peak contact force and a higher energy absorption capacity. Besides, the joint opening and the damage area could be significantly reduced by the interlocking feature. A parametric study is also conducted to investigate effects of the confining load and the initial impact velocity on the performance of the interlocking system.