Rock masses stresses investigation based on overcoring with CSIRO cell test and 3D finite element modeling in Aqabat Al-Sulbat Road at Aseer Province, Saudi Arabia: Numerical approach

Abstract

Rock masses slopes stability is a real problem and represents an important concern in Aseer Province, in order to avoid rock fall process on the main roads. For this reason, it is necessary to explore, inspect, investigate, and understand the natural stresses within these rock masses taking into a consideration the third dimension. In this sense, the state of stresses within the rock masses depends on the characteristics of Commonwealth Scientific and Industrial Research Organization (CSIRO) cell and the dimension of the overcoring hole. Furthermore, in order to achieve the 3D modeling, the characteristics of the rock masses mentioned before are introduced in the model using “Surfrac” program written in Pascal and FORTRAN, coupled with “Abaqus” software to simulate the stresses matrix in the model. As a result, the main findings of this research are summarized in three points: the first is dealing with the CSIRO cell itself, where the direction of the gauge is important during the measurement of stresses; in fact, the perpendicular gauges work better than those parallel to the hole axis. The second is evident from the model that the direction of hole must be perpendicular to the dip direction of the rock layers, allowing giving better results compared to others. The third is the selection of the measurement site requiring involving the regional stresses of the study area according to geological investigation. Finally, it is interesting to carry out geophysical exploration in the site to understand the local tectonic movement of rock masses. Moreover, a detailed map can highlight the main fractures and faults network and overlap them with the most important projects deployed in Aseer province for maintenance and monitoring.