Experimental Study on the Dynamic Response of an Immersed Tunnel Element Moored inside the Harbor

Abstract

Floating, pouring, prefabrication, and temporary storage of the immersed tunnel element require mooring inside a harbor or a dock. However, the dynamics of a moored tunnel element in such semi-open waters are rarely studied, and some mechanisms are not well understood yet. Clarifying the dynamic response characteristics of a tunnel element moored inside a harbor is useful for the evaluation and design of the mooring system. In this paper, by carrying out physical model tests, the law of wave development in the harbor was investigated, and the motion response of the tunnel element and cable force of the mooring system were also measured. Dynamic response characteristics under different environmental factors, the influence of tunnel element load conditions, and the mutual interference of multiple elements moored simultaneously were analyzed. The results show that dynamic response characteristics under wind are significantly different from those under waves. Under no-load or half-load conditions, which correspond to greater freeboard-to-draft ratios, the dynamic responses of the tunnel element are more unfavorable than those under heavy-load or full-load conditions. The scheme of simultaneous mooring of multiple elements inside a harbor is feasible if there is appropriate spacing between them.