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

Dealing with uncertainty, caused e.g. by materialparameters varying in a wide range or simply by alack of knowledge, is one of the important issuesin deep excavation projects. Traditionally, thereare two approaches that reflect uncertainty in thedesign; deterministic and non-deterministic. Theusage of numerical methods such as the FiniteElement Analysis as a deterministic approach, isbecoming more widespread. On the other hand,engineers have not yet applied non- deterministicanalysis in deep excavations broadly. The articlepresents RS-FEM (random set finite elementmethod), a non-probabilistic method, in Iran-Zamin deep excavation project in Tehran. In thisproject, cohesion, angel of internal friction andstiffness of soil are considered as major variables.Sensitivity analysis is employed to identify thevariables that have negligible effects on desiredresults and finite element analysis is applied withtwo groups of variable. Horizontal displacementand safety factor play important role in deepexcavations and due to this fact, these parameterhave been considered as a major response tointerpret. This result has been compared to in-situmeasurements and it shows that lower bound ofresponse of finite element analysis is somehowsimilar to measurements. Finally, the accuracy andvalidity of this method has been investigated ingeotechnical problems.

Keywords:

Iran-Zamin excavation , uncertainty , random set finite element , sensitivity analysis , failure