numerical analysis and monitoring of a rockfill dam at the end of construction (case study: vanyar dam)

in this study, the mechanical behavior of vanyar dam was evaluated at the end of construction. a two-dimensional numerical analysis was conducted based on a finite element method on the largest cross-section of the dam. the data recorded by the instruments located in the largest cross-section were compared with the results of the numerical analysis at the place of instruments. the settlement, pore water pressure, and total vertical stress were the parameters used for evaluating the dam behavior at the end of construction. the results showed that the settlements obtained from the numerical analysis were in reasonable agreement with the data recorded by the instruments, which proved that the numerical analysis was implemented based on realistic material properties. in addition, the difference between the instruments and the numerical analysis in terms of total vertical stresses was discussed by focusing on the local arching around the pressure cells. furthermore, the arching ratios were calculated based on the results of the numerical analysis and the data recorded by the instruments. moreover, the pore water pressures and total vertical stresses, recorded by piezometers and pressure cells, respectively, were the two parameters utilized for evaluating the hydraulic fracturing phenomena in the core. the results demonstrated that the maximum settlement obtained from the numerical analysis was 1 m, which corresponded to 46 m above the bedrock on the core axis. the recorded data in the core axis indicated that maximum settlement of 0.83 m happened 40 m above the bedrock. in addition, maximum pore water pressure ratio recorded by the instruments (ru =0.43) was more than that obtained from the numerical analysis (ru =0.26) this difference was due to the local arching around the pressure cells. furthermore, the arching ratios in vanyar dam were found to be 0.83 to 0.90. in general, the results revealed that the dam was located on a safe side in terms of critical parameters, including settlement and hydraulic fracturing. in addition, results of the numerical analysis were consistent with those provided by the monitoring system