ABSTRACT
This chapter describes the proposed back analysis procedure for determining the strength parameters of geomaterials from measured displacements. In order to overcome the paradoxes of design and monitoring of slopes, monitoring results such as measured displacements should be linked with the strength parameters, such as cohesion and internal friction angle of geomaterials. Once the strength parameters are determined, the factor of safety of slopes can be calculated and the original design can be verified. If the back-calculated factor of safety is still sufficiently large, then the slopes must be adequately stable for the construction to proceed. However, if the factor of safety is less than that adopted at the design stage, additional support measures, such as drainage borings, earth anchors and piles, should be installed to stabilise the slopes. In addition, the design of the additional support measures is possible using the strength parameters determined by back analyses.
