Updated: Sep 26
DAARWIN has been used to help to understand how the water level behavior inside a tailing dam was, considering that this phenomenon has an important influence on the dam’s stability. DAARWIN was used to optimize groundwater flow parameters defined in a predictive numerical model to provide the best possible match to the measured values.
Among different possible optimization scenarios, it was finally decided to carry out a calibration of the horizontal permeability hence seeing the change on the ratio of horizontal and vertical permeability.
A sensitivity analysis was carried out before the backanalysis to identify what geotechnical units were the most sensitive. The purpose of the sensitivity analysis was to identify the units that control the groundwater flow behavior and, consequently, reduce the size of the problem.
The methodology followed consisted in increasing and decreasing 10 times the horizontal and vertical permeability (keeping the ratio constant) of each geotechnical unit with respect to design values. Only one geotechnical unit was changed at each calculus. After extracting the results, the area within the range of permeabilities was calculated. Those with the maximum difference were considered the most sensitive.
To carry out the backanalysis (soil parameters calibration) from the monitoring data, the horizontal permeability of the four most sensitive geotechnical units was the parameter selected to be identified.
Regarding the monitoring data, the last data of the whole piezometers installed on the site were analyzed.
The permeabilities considered were those with the minimum error between measured and calculated water head.
In conclusion, the use of DAARWIN tool in this project allowed to better know the hydraulic properties inside the dam. Therefore, the findings obtained in this particular project provided a case study to be considered in future designs. civil engineering, geotechnical, software engineer, geotechnical engineering, borehole