Document: NUREG-0800
Document ID: ce3522a1-5c42-492a-95d7-9087534cf63c
Document Type: srp
Title: STABILITY OF SLOPES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070270.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.5
CFR Part: 
CFR Title: 

Content:
d to demonstrate that there is an adequate margin of safety. A number of different methods of analysis are available in the literature. Computer analyses should be verified by manual methods. Analysis using both deterministic and probabilistic approaches is desirable.23 To be acceptable, the static analyses should include calculations with different assumptions and methods of analysis to assess the following factors: 1. The uncertainties with regard to the shape of the slope, boundaries of the several types of soil within the slope and their properties, the forces acting on the slope, and pore pressures acting within the slope. 2. Failure surfaces corresponding to the lowest factor of safety. 3. The effect of the assumptions inherent in the method of analysis used. 4. Adverse conditions such as high water levels due to the probable maximum flood (PMF), sudden drawdown, or steady seepage at various levels. In general, safety factors related to the slope hazard are needed; however, actual values depend somewhat on the method of analysis, on the assumptions concerning the soil properties, on construction techniques, and on the range of material parameters. To be acceptable, the dynamic analyses must account for the effect of cyclic motion of the earthquake on soil strength properties. Actual test data are needed for both the in situ soils as well as for any materials used in the construction of dams or embankments. As discussed above, the various parameters, such as geometry, soil strength, modeling method (location and number of elements (mesh) if a finite-element analysis is used), and hydrodynamic and pore pressure DRAFT Rev. 3 - April 1996 2.5.5-6 forces, should be varied to show that there is an adequate margin of safety (Refs. 34 and 35). Where liquefaction is possible, major dam foundation slopes and embankments should be analyzed by state-of-the-art finite-element or finite difference methods of analysis. Where there are liquefiable soils, changes in pore