Investigation of rock fall mechanism and risk mapping of Yadak village area in north of Khorasan Razavi

Rock fall hazard assessment is a fundamental land-use planning tool in high mountain area, where human settlements progressively develop across side valley areas, using the worth of potential losses and the restoration costs. The aim of this paper is to evaluate the potential of rock falls along the north east of the Yadak village. This village is located in the Khorasan-Razavi province near the Ghochan city in the northeast of Iran. The existence of the Tirgan limestones with abundant joints and fractures in the north part of the Yadak village causes instability such as rock falls that provide many problems for the residents. Many factors such as rock type, slope morphology, drainage pattern and the seismic activity are considered in this research as affecting factors. For joints investigation in the study area, the dip and dip direction of more than 180 discontinuities measured and analyzed using dips. Since most of the slope instability along the north part of the Yadak village are the rock falls type. Rocfall software was used to investigate the rock fall mechanism. Finally, the rock fall hazard zonation map is prepared using GIS program.