An Improved Method of Estimating Slip Surface Through Ground Surface Displacement (of Landslide)
Abstract
After a landslide has occurred, it is important to estimate its characteristics and size at an initial stage of the disaster and to speedily take countermeasures for minimizing the damage. The existing method, however, has problems about safety and speed, as it requires entering the landslide mass. Now, as a faster method of grasping the size of the landslide, we, reviewing the method of estimating the shape of slip surface through the ground surface displacement vector, have developed a program for speedy estimation of it then and there. According to the result of the verifiction using the ground surface displacement vector measured at the actual landslide site, the calculted slip suface was comparatively in close accordance with the real slip surface, if measurement points of ground surface vectors were properly arranged. But when the number of measurement points at the head or toe was small and when the surface shape was complicated, this method proved less satisfactory. This paper describes an improved method and its verification as follows. 1. When there was great difference between displacement vectors of adjacent blocks, equal gradient condition was strict, and the estimated accuracy of slip surface falls, so weight coefficient determinant was added to the equal gradient condition equation of block boundaries. 2. As to the estimation of the scarp of the head, a new parameter (ground boundary parameter: arbitrary boundary point which moves toward the scarp) was introduced. The result confirmed that this improved method can be effectively applied to chair type and ship bottom type landslides whose displacements have deep sinking forms at their heads.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.H43I..08T
- Keywords:
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- 1810 Debris flow and landslides;
- 1816 Estimation and forecasting