ABSTRACT
Fracture characterization of potentially unstable cliffs is a crucial problem which can only partly be solved by geological measurements at the surface. This chapter aims to combine Laser Scanning and geophysical techniques for obtaining the best possible image of the fracture pattern at the surface and inside the rock mass. Two limestone cliff sites around Grenoble, exhibiting different geometrical and geotechnical features, were investigated in order to show the potential and the limits of the methods. Rock fall hazard assessment is a complex problem in high cliff areas, due to the difficulty of measuring and mapping geological structures on the cliff face, and to the little information about the internal discontinuities provided by these conventional mapping techniques. Airborne and terrestrial laser scanning techniques are increasingly used for mapping in landslide detection and rock engineering. The geophysical methods have been increasingly used for cliff investigation, both on the plateau above the cliff and on the cliff face itself.
