The retaining wall supporting the garden around a dwelling in an area of steeply sloping ground had started to suffer structural distress, and the public road at the toe of the wall also started to show signs of cracking. However, the dwelling itself showed no signs of movement. We have been instructed to undertake an assessment of the likely causes of ground movement.
We commenced with a desk study including a review of the history of movements in the area, and an inspection of the site by an engineering geologist experienced in geomorphological mapping.
A Conceptual Ground Model was prepared and a site investigation was then designed to check this model and provide further information on the ground and groundwater conditions.
Our investigation overcame significant access constraints, but involved dry sampling of the soils, coring of the bedrock and the installation/monitoring of inclinometers and standpipe piezometers.
The Conceptual Ground Model was updated with the information obtained in the investigation, and the likely failure mechanisms presented to the technical project team. An assessment was also made of the scale of likely future movements in the area.