DESIGN OF SLOPES ASSOCIATED WITH HIGHWAYS BRIDGES AND CULVERTS

Seven of the more widely used methods of analysis of slope stability, applicable to planar, circular and arbitrarily shaped slip surfaces, are reviewed in detail. Other methods developed for arbitrarily shaped slip surfaces but more cumbersome in their application are outlined. The analyses are all presented in terms of effective stress, allowing consideration of the pore water pressure distribution in A slope, but are equally applicable in terms of total stress to "immediate stability" situations where pore pressures can be ignored. A range of slope stability charts are available as design aids for the rapid analysis of simple slopes in homogeneous soils, and applicable to circular slip surfaces. The site investigation as the process of assembling the relevant data required to carry out the stability analysis of a slope is reviewed. Guidelines for the determination of the relevant soil shear strength parameters and pore pressure distribution applicable to particular stability situations are presented. The general nature of slope stability problems in particular soil types is discussed. An appreciation of the sources of uncertainty in stability parameters and in the method of analysis is presented. While the uncertainties in the stability analysis may be partly self-compensating, a higher probability of failure is associated with a greater degree of uncertainty. The factor of safety adopted in the design of a slope should be consistent with the probability of failure, and hence should reflect in particular the degree of uncertainty in the data used. Guidelines for the selection of an appropriate factor of safety are presented. Finally practical methods of improving slope stability are reviewed. (TRRL)

• Corporate Authors:

  National Roads Board, New Zealand

  Road Research Unit, P. O. Box 12-041
  Wellington,   New Zealand 
• Authors:
  • Hadfield, G J
  • Toan, D V
  • Blakeley, J P
• Publication Date: 1981-6

Media Info

• Features: Figures; References; Tables;
• Pagination: n.p.

Subject/Index Terms

• TRT Terms: Bridge design; Bridges; Charts; Coefficients; Culverts; Design; Design methods; Equilibrium (Mechanics); Failure; Highway bridges; Homogeneity; Pore water pressures; Portland cement concrete; Safety; Shape; Shear strength; Slip surfaces; Slope stability; Slopes; Soil stabilization; Soils; Strength of materials; Stresses; Structural design; Ultimate load design
• Uncontrolled Terms: Site investigation
• Old TRIS Terms: Slope protection
• ITRD Terms: 6486: Chart; 9011: Design (overall design); 7145: Equilibrium; 5520: Failure; 5916: Homogeneity; 6452: Limit; 5762: Pore water pressure; 5504: Safety coefficient; 9073: Shape; 5531: Shear; 5722: Site investigation; 5794: Slip surface (soil mech); 2831: Slope (terrain); 5783: Slope stability; 4156: Soil; 5544: Strength (mater); 5575: Stress (in material)
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00349994
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Report/Paper Numbers: Project 47 Monograph
• Files: ITRD, TRIS
• Created Date: Jun 30 1982 12:00AM