Bridge monitoring in Japan: the needs and strategies.

This paper discusses the development of bridge monitoring in Japan. Firstly, the background of the development of bridge monitoring is described. The need for monitoring was originally influenced by geographical conditions. Due to the fact that Japan is prone to natural disasters and has a severe environment for deterioration; monitoring of the environment and loading conditions with respect to natural hazards has been conducted for several decades. In the last decade, bridge monitoring has extended its function as an instrument for an efficient stock management. Based on the accumulation of bridge stock and concentrated construction in former years, many bridges in Japan are expected to have serious deterioration problems within the next decade. The second part of the paper describes the concept of bridge monitoring as an essential part of risk reduction. To improve bridge safety, monitoring technologies for risk and vulnerability are implemented. In this concept, structural health monitoring serves as a tool for vulnerability monitoring. The third part of the paper outlines strategies implemented for bridge monitoring in Japan. They are categorised into three main groups according to the purpose of monitoring: natural hazard and environment condition, effective stock management, and failure prevention. Examples of bridge monitoring systems that implement these strategies and the lessons learned from monitoring experiences are also presented in this paper. [ABSTRACT FROM AUTHOR]