Investigation of the arching in rock-fill dam ten years after end construction using Numerical analysis and monitoring

In the present study, the mechanical behavior of Vanyar Rock fill dam has been evaluated ten years after the completion of the dam body.3D numerical analysis was performed based on the finite element method for the body and dam supports in Midas software. The data recorded by the tools in the dam body were compared with the results of numerical analysis at the tools site. The results showed that the amount of settlement, amount of pore pressure and the total stress obtained from the numerical analysis were consistent with the data recorded by the instruments. In linear behavior between instrumentation data and numerical analysis of settlement, pore pressure and total stress correlation coefficients were 84, 67 and 99%, respectively. .The maximum settlement values obtained from numerical analysis and instrumentation were 1.79 and 1.90 m, respectively, for pore pressure of 450 and 420 kPa, for total stress of 1440 and 1205 kPa. According to the calculations, the maximum ratio of Arching coefficient in Vanyar dam obtained from instrument readings and numerical analysis was 0.77 and 0.91, respectively, which are both less than one, as well as the maximum Ru from numerical analysis and instruments installed in the core Respectively 0.35 and 0.47. Which are less than the predicted value in the design stage of 0.5. Therefore there is no possibility of core curvature, which indicates that the dam is within safe range in terms of hydraulic failure.