This code of practice outlines the general requirements for the design and construction of retaining walls. It covers aspects like site investigation, materials, calculation of earth pressures, stability checks, drainage measures, and construction supervision.
Covers general principles and guidelines for the design and construction of various types of retaining walls.
Quick Reference Values
Minimum Factor of Safety against Sliding1.5
Minimum Factor of Safety against Overturning1.5
Minimum depth of foundation below ground level900 mm
Allowable tension in concrete for overturning check0 N/mm2
Minimum weep hole diameter75 mm
Key Formulas
Pa = 0.5 * Ka * γ * H^2 — Rankine's active earth pressure
Pp = 0.5 * Kp * γ * H^2 — Rankine's passive earth pressure
Ka = (1 - sin(φ)) / (1 + sin(φ)) — Coefficient of active earth pressure for level backfill
Practical Notes
Provision of effective drainage (weep holes, granular backfill, longitudinal drain) is the most critical aspect for the safety and longevity of a retaining wall, as it prevents buildup of hydrostatic pressure.
This is a general code; for specific applications like bridge abutments or waterfront structures, other specialized codes (e.g., from IRC or other relevant bodies) must be used in conjunction.
Always consider potential surcharge loads from adjacent traffic, structures, sloped backfill, or temporary construction activities when calculating earth pressures.