Research On Simulation-based Pre-control Of Ship Navigation Safety In Bridge Area Shanghai Jiao Tong University

With the rapid development of economy and transportation, massive bridges crossing navigational waterways in inland rivers, straits and gulfs were constructed or are being constructed. On the one hand, more bridges have promoted tri-dimensional transportation construction and development of regional economy. On the other hand, bridges have resulted in negative impact on the navigation. Some bridges even face severe risk of ship-bridge collision. More bridges, bigger ships and larger vessel traffic density bring greater risk of ship-bridge collision. In China, massive bridges have been built, been constructed or been proposed, such as Donghai Bridge of Yangshan Deep-water Port, Hangzhou Bay Cross-Sea Bridge, Su-Tong Bridge, Wuhan Parrot Island Bridge, Hongkong-Zhuhai-Macau Bridge, and so on. Safety of ships and bridges is becoming a prominent issue for management of ships and navigation. In order to conform to the urgent need of navigation safety in bridge areas, it is necessary to carry out research on pre-control to ensure safety of ships and bridges, to pilot ships safely and effectively.There are three determinant causes inducing ship-bridge collision, including human factors, mechanical failure and environment factors.Under severe environment situation or sudden accidents, i.e. out of control, some ship-bridge collision incidents are caused by mishandling due to psychological stress of pilots. Others are caused by hydrodynamic interaction between ships and bridges. Some pilots do not understand the intrinsic mechanism of hydrodynamic interaction between ships and bridges; do not know the potential consequences induced by hydrodynamic interaction, for an example, incomplete control state of ship motion. In order to ensure navigation safety in bridge area, an active pre-control system of anti-collision between ships and bridges was established based on mathematical models of under-control ship, incomplete-control ship and out-of-control ship.To ensure navigation safety in bridge area, the following three issues should be solved.The first one is to predict the trajectory breadth of under-control ship. Taking comparing result of trajectory breadth and clean breadth of bridge as the safety criterion to judge the under-control ship can pass bridge safely or not.The second one is to assign precaution area, in which ship-bridge collision may happen if under-control ship loss control due to wind and current drift motion. In this thesis, the area is called as Critical Collision Zone (CCZ) of out-of-control ship.The third one is to predict that in which zone the incomplete control state will happen for ships under head-on, overtaking and overtaken situation and for ships navigating near piers. In this thesis, the zone is called as Critical Uncontrollable Zone (CUZ) of incomplete-control ship.To establish active pre-control system of anti-collision between ships and bridges will significantly reduce the impact of human factors and the probability of ship-bridge collision accidents, based on the precaution of trajectory breadth of under-control ship, precaution area for out-of control ship and incomplete control zone for incomplete-control ship.Main contents of the thesis are as follows:(1) To illustrate the necessity and urgency of research on ship navigation safety in bridge area, statistics of collision accidents between ships and bridges were compiled.(2) Based on the ship maneuverability theory, maneuverability mathematical model for ship under control was set up which could be used to simulate ship's motion trajectory and to identify the various ship's safety passing width. Considering low speed characteristics of ships navigating in bridge area, wind-induced and current-induced ship drift model were established.(3) With ship maneuverability mathematical model, ship maneuverability simulator was used to simulate ships'navigation trajectories.(4) Concept of CUZ, in which the rudder cannot provide sufficient lateral force and/or moment to maintain the ship under control when ship approaches to other ship or marine structure, was put forward firstly. CUZ was systematically analyzed with different water depth, ship length, ship speed and stagger between ships. New generic equation of CUZ was established.(5) Based on mathematical model for ship out of control, considering CUZ, CCZ model was put forward firstly.(6) With mathematical model for ships under control, out of control and uncontrollable ship, initiative pre-control system of anti-collision between ships and bridges was firstly put forward.Based on simulation, mathematical models for ships under control, out of control and uncontrollable ships were established. Ships'safety passing width, CUZ and CCZ were put forward and analyzed. Finally, pre-control system of anti-collision between ships and bridges was established. The methods proposed in this thesis may provide a new way to research navigation safety in bridge area.