Assessment of discontinuous rock slope stability with block theory and numerical modeling: a case study for the South Pars Gas Complex, Assalouyeh, Iran

In this study, a geotechnical model has been used to analyze the stability of a discontinuous rock slope. The main idea behind block theory is that it disregards many different combinations of discontinuities and directly identifies and considers critical rock blocks known as key blocks. The rock slope used as a case study herein is situated in the sixth phase of the gas flare site of the South Pars Gas Complex, Assalouyeh, Iran. In order to analyze the stability of discontinuous rock slopes, geotechnical modeling which was divided into geometrical sub-modeling and mechanical sub-modeling has been utilized. This model has been established upon the KGM (key-group method) algorithm which was based on the limit equilibrium method and block theory and prepared and coded by the Mathematica software. According to the results of the stability analysis, the analyzed slope was determined to be in the category of needs attention, and the security level, calculated through the FORM (first-order reliability method) analysis, was estimated to be 1.16. In order to verify the model, the results obtained from the model were compared with those of the UDEC software, which is a numerical method based on distinct components. As a conclusion, it was determined that the results of the model agreed well with those of the numerical method.