Coulomb Theory Active Pressure Coefficient, Ka Ka -- Effective soil friction angle, φ' (degrees) Backslope angle, β (degrees) Back face of wall angle to horizontal, θ (degrees) Wall friction angle, δ (degrees) Calculate Ka Ka calculation details
Chart Interpolation Passive Pressure Coefficient, Kp Kp -- Select Kp chart to use Chart for Vertical Wall with Sloping Backfill Chart for Vertical and Sloping Walls with Horizontal Backfill Soil friction angle, φ (degrees) Wall friction angle, δ (degrees) Backslope angle, β (degrees) Back face of wall angle, θ (degrees) Calculate Kp Kp interpolation details