A property development is planned for a site formerly used for sand extraction. The sand extraction has left exposed a layer of clay at the base of the slope. A line of large oak trees sit at the top of the embankment 1m from the edge at 10m intervals. For many months of the year the ground water level is at the surface. The developer is concerned that the slope is potentially unstable. The limit of the land available for geotechnical work is 15m from the top edge of the embankment. A borehole sample taken at the top of the embankment reveals a 5m layer of sand overlays a layer of clay at the site.
Suggest a way to stabilise the slope analysis you consider appropriate. Select the best solution and justify your choice. You should consider cost, performance and aesthetics.