Transmission And Substation Foundations - Technical Design Manual (TD06088E)

N γ Bearing Capacity Factor for SoiL Weight and Foundation Width. Q H .....................................................................Individual Helix Capacity D .................................................................Vertical Depth to Helix Plate φ .......................................................................Angle of Internal Friction γ ................................................................ Effective Unit Weight of Soil 4-11 s u ..................................................................... Undrained Shear Strength 4-12 F c .......................................................................................Breakout Factor 4-12 K 0 .............................................. Coefficient of Earth Pressure at Rest 4-13 A c .......................................................Surface Area of Truncated Cone 4-13 S a ......................................................Undrained Shear Strength of Clay 4-14 Q M .Total Bearing Capacity of Multi Screw Pile/ Helical Anchor 4-18 α ............................................................................................Adhesion Factor 4-19 Q s ............................................................................ Capacity Upper Limit 4-21 psf...................................................................... Pounds per Square Foot 4-23 Q t ........................ Total Ultimate Multi-Helix Anchor/Pile Capacity 4-27 σ ` vo .............................................................Effective Overburden Stress 4-31 (N 1 ) 6o ................................................................ Normalized SPT N-value 4-32 σ o ............................................Mean Normal Stress for Grout Column 4-37 D ....................Diameter of Timber, Steel or Concrete Pile Column 4-37 f s ................ Sum of Friction and Adhesion Between Soil and Pile 4-37 ∆ L f .......................................................................Incremental Pile Length 4-37 C a ...................................................................................... Adhesion Factor 4-38 s o ................................................................................. Mean Normal Stress 4-37 q.................................................. Effective Vertical Stress on Element 4-38 K..................................................Coefficient of Lateral Earth Pressure 4-38 ø................. Effective Friction Angle Between Soil & Pile Material 4-38 S........................ Average Friction Resistance on Pile Surface Area 4-40 P o ............................................................Average Overburden Pressure 4-40 K p ..............................................Coefficient of Passive Earth Pressure 4-45 K a ................................................Coefficient of Active Earth Pressure 4-46 H ..................................................Height of Wall or Resisting Element 4-46 P a ............................................................................ Active Earth Pressure 4-46 4-11 4-8 4-10 4-10

DESIGN METHODOLOGY

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