Monitoring and identification of landslide slopes by GPS survey

点击翻译按钮获取中文摘要

Twelve observing points and benchmarks are settled in and around the Taguchi landslide, Okayama Prefecture. Landslide movement of about 2cm a year had been observed by borehole inclinometer in the lower part of thie landslide, however, the middle and upper part of this landslide had not been investigated. In order to recognize sliding slopes and to depict the boundary of landsliding blocks, static GPS surveys were carried out four times in a year. Small amount of landslide movement was detected at the middle part, but no obvious movement was detected by these surveys. No more than 2 cm per a year of movement was detected at the lower part of this landslide was detected, and it coincides with the borehole inclinometer monitoring. More than 5 cm of movement was detected at a point on a new road embankment and it showed failure of the embankment was possible. Municipal government decided to reinforce the embankment from this survey result.As a result, GPS survey was proved to have ability to detect landslide movement of greater than 5 mm. It is enough precision for the purpose of monitoring and identification of landslide slopes, although stable benchmark should be chosen carefully.