Rapid Drawdown - Duncan Three-Stage Total Stress Method
July 14, 2009
Rapid drawdown is one of the most severe loading conditions that can occur along drainage channels. During spring flooding, the levels in canals can be high. Once the floodwaters recede, the levels in these drainage channels can drop quite rapidly and result in shallow slope failures. These shallow failures can lead to larger slope deterioration if they are left unattended.
Analysis of rapid drawdown is commonly required for any earth levee design. There are two commonly used methods:
SVSlope allows analysis by either of these methods. The traditional total stress analysis method is implemented in order to allow comparison in the software between the two. The effective stress method has typically been avoided in the past due to the inability of software to perform this type of analysis, but SVFlux and SVSlope allow easy analysis of effective stress scenarios.
An example of the rapid draw-down analysis may be found in SVSlope_Group_3 > RDD01.svm, pictured above. It is part of our distributed public models, which are available with the download of SVOffice 2009. A movie illustrating the ease of this calculation is available. An animated tutorial demonstrating the entry of geometry is also available.