Evaluate the capability of key-groups method development using numerical methods for finding the critical key-group in analysis of stability of rock slopes

The key block is a well-known method in stability analysis of jointed rock slope. This method is based on the finding & analysis of the key block. In this method if none one of the blocks were unstable we can conclude the rock mass is stable. Sometimes a collection of some stable blocks makes an unstable group, therefore the stability analysis of jointed rock masses leads to investigation of the groups of blocks that are potentially dangerous for the stability of a rock slope. The key-groups method detects the critical groups and focuses the stability calculations on them. For three dimensional development and also increase the efficiency, accuracy and speed of key-group method, combining it with numerical methods is focused. This objective can be achieved in two parts: A: finding the critical key-group and analysing the interaction between the blocks of a key-group. B: analysing the interaction between the critical key-group and rock mass and analyse the stability of rock mass. In this research the blocks interaction of key-groups was analysed, firstly to evaluate the performance of the key-groups method and then to choose the best numerical methods for method development based on fuzzy multi criteria decision maker. At the end, discontinuous deformation analysis was selected as the compatible numerical method with standards. These two methods were combined and the algorithm as well as the primary program were prepared in mathematica software. The results reveals combining the key-groups method with numerical methods results in good performance of identifying and assessing the sustainability of key-groups.