Continuous monitoring system for excavated slopes using GPS

Kochi Prefecture frequently suffers from torrential rains during the typhoon season.
In September 1998 the Kochi Expressway was hit by an unprecedented heavy rain with a maximum hourly rainfall of 117 mm and a continuous rainfall of 951 mm. Along this expressway, which runs through steep mountains, there are many high and long slopes, which not only require a lot of work and time for inspection during heavy rains but could cause a major disaster. In fact, it was found after the torrential rains that some slopes were deformed.
Afer this experience, it was decided to urgently develop a slope management system capable of quickly detecting the risk of failure due to torrential rains and earthquakes. In September 1999, the Continuous Slope Monitoring System using GPS was introduced at five large slopes along the Kochi Expressway. This system is designed to display information on the displacements of the slopes on monitors installed at the operation office and send messages to the mobile phones of staff in case of emergencies.
Studies, including analysis on diurnal and seasonal fluctuations of the data obtained from this system, will continue to improve the accuracy of the system, and allow it to be used as a means of disaster prediction and effective slope inspection.

(Kochi Operation Office of the Shikoku Branch, Japan Highway Public Corporation)

Outline of the system

Data collection using slope observatory built on large slope and fixed observatory

ITS HANDBOOK 2000-2001（Nov 2000）