Many building sites have slopes on them, whether they are steep bank waterfront or mountainous terrain. The most recent BC Building Code enacted strict guidelines for building above or below slopes. Most people think of slope stability issues are important for building at the top of a steep slope. However, there is cause for concern when building at the base of a slope as well.
When building in a designated steep slope area, a Slope Stability Assessment has to be conducted. Depending on the type of soil and how close to the crest of a slope the developer would like to build, various methods for determining a safe setback are used. In the most stringent cases, such as building as close to the crest of a slope as possible, we employ drilling to determine soil stratigraphy, laboratory soil testing and computer modelling to determine a safe building location according to the BC Building Code. Various Geotechnical Engineering techniques, including those in conjunction with a Structural Engineer, can be implemented to achieve a desired setback.
When building at the base of slopes, rock fall hazards, landslide run out, and other issues are considered when establishing a safe setback distance.