Slope stability problems along the Israeli Mediterranean beach cliffs and ways for improving its stability

R. Ben-David
ROVED, Geological Consultant, Lion, Israel

D. David
Consulting Foundation Engineer, Herzlia, Israel

ABSTRACT

The cliffs along the Mediterranean coast of Israel are composed of friable sandstone and clayey-sandy soil of Late-Pleistocene age in which constant erosion occurs. Geotechnical works south of the city of Netanya, along some 4 km of the coastal cliffs, included a geotechnical field survey and a detailed aerial photography study was carried out. The retreat of the cliff front during the last 30 years was 0-25 m, averaging 15 m (~0.5 m/y). It was clear that erosion by the waves along the foot of the cliffs and runoff towards the beach upon their surface are the most destructive processes. Therefore, a design method to prevent runoff towards the beach and to reduce the impact of the waves at the cliff base may prevent landslides along the cliffs. Land use pressure for construction in these environments requires the cooperation of geologist, geomorphologist soil and marine engineers to develop methods to improve the cliffs' stability.