Professional Presentations:

Waterside Stability of Delta Levees; Hultgren, Edwin M.; CALFED Bay-Delta Program Science Conference, Sacramento, California; January 2003. - Historically, the exterior (waterside) slopes on most Delta levees were designed using prescriptive criteria, most commonly 2:1 (horizontal to vertical) slopes. 

Actual levee slopes vary widely, from much flatter to much steeper.  As levee crests are raised to improve flood protection, stability of waterside slopes will be affected.  Proper characterization of peat strength beneath waterside slopes is needed for assessing stability of the slopes.  Many factors may affect undrained strength in the peat.  In the study, the results of consolidated-undrained strength tests are used to assess undrained strength.  The affects of strength increases from seepage are also considered. Computed factors of safety for slope stability for various shear strength characterizations are compared to observed performance of delta levees.