Reliability analysis in Iran-Zamin excavation by application of Random Set Finite Element Method

Dealing with uncertainty, caused e.g. by material parameters varying in a wide range or simply by a lack of knowledge, is one of the important issues in deep excavation projects. Traditionally, there are two approaches that reflect uncertainty in the design; deterministic and non-deterministic. The usage of numerical methods such as the Finite Element Analysis as a deterministic approach, is becoming more widespread. On the other hand, engineers have not yet applied non- deterministic analysis in deep excavations broadly. The article presents RS-FEM (random set finite element method), a non-probabilistic method, in Iran-Zamin deep excavation project in Tehran. In this project, cohesion, angel of internal friction and stiffness of soil are considered as major variables. Sensitivity analysis is employed to identify the variables that have negligible effects on desired results and finite element analysis is applied with two groups of variable. Horizontal displacement and safety factor play important role in deep excavations and due to this fact, these parameter have been considered as a major response to interpret. This result has been compared to in-situ measurements and it shows that lower bound of response of finite element analysis is somehow similar to measurements. Finally, the accuracy and validity of this method has been investigated in geotechnical problems.