Rapid Drawdown / Filling Transient Effective Stress Method
July 14, 2009
Analysis of rapid drawdown is commonly required for any earth levee design. There are two commonly used methods:
It is commonly viewed that a total stress analysis is most useful for a rapid draw-down case while an effective stress analysis is most useful for a long-term draw-down scenario. This is a misconception and the latest version of SVFlux and SVSlope allows for easy comparisons between the two. The effective stress analysis has traditionally been avoided due to the complexity of performing such an analysis in software. It remains a more rigorous analysis than the total stress analysis and has the benefit of providing a detailed picture of the performance of pore-water pressures during a draw-down scenario.
An example of the rapid draw-down analysis may be found in SVSlope_Group_3 > RapidDrawdownEffective.svm, which is part of our distributed public models (available with the download of SVOffice 2009). Pictured above is the effective stress method in SVFlux, showing the pore-water pressures. Below are the final results from SVSlope.
Ease of Use
SVSlope can also easily be used for the analysis of rapid filling. The example below illustrates the use of the software for the filling scenario. It is interesting to note the use of mesh refinement to improve the accuracy of the filling contours.
An example of the filling analysis may be found in our distributed public models as SVSlope_Group_3 > ReservoirFilling (available with download of the software).