Discontinuity controlled probabilistic slope failure risk maps of the Altindag (settlement) region in Turkey

The evaluation of potential rock slope problems using stereographic project ion techniques known as kinematic analysis is one of the most important par ts of a slope stability investigation to be carried out in jointed rock med ia. In conventional stereoprojection techniques for the assessment of possi ble rock slope failures, the peak orientations of joints together with the slope geometry and the friction angle of the weakness planes are used. Othe r possible joint orientations which may be encountered in the rock media ar e ignored, although they belong to the group of joint peak orientations. In this study, nearly vertical jointed andesites cropped out at the Altindag settlement region in Ankara were studied in order to evaluate the relevance of this ignored discontinuity orientation data on slope stability. As a re sult: probabilistic risk maps for planar, toppling and wedge failures were produced using the kinematic rules and digital elevation model of the study area. The comparison of the distribution of the actual failures in the are a and the probabilistic risk maps prepared for the study area revealed that all of the identified failures are found to be located in the higher risk zones on the probabilistic risk maps. (C) 2000 Elsevier Science B.V. All ri ghts reserved.