This code provides guidelines for the structural design of unreinforced masonry buildings. It covers materials like bricks and mortar, design principles using the allowable stress method, and specific requirements for stability, walls, and columns, including crucial provisions for earthquake-resistant design in different seismic zones.
Specifies design and construction requirements for load-bearing and non-load-bearing masonry walls and buildings.
Quick Reference Values
Maximum slenderness ratio for a load bearing wall27
Maximum eccentricity for axial loadt/6 (where t is thickness)
Minimum thickness for two-storey load-bearing brick wall190 mm
Typical curing period for masonry7 days
Minimum grade of mortar for load-bearing clay brick wallsM2
Key Formulas
SR = Effective Height / Effective Thickness — Slenderness Ratio Calculation
ks = (1.25 - SR/24) — Stress Reduction Factor for Slenderness (for SR > 6)
kb = 1.0 + 0.05(e/t) — Stress increase factor for eccentricity (for e <= t/6)
Practical Notes
Mortar quality is critical and often the weakest link. Strict supervision of batching, mixing, and application is essential for achieving designed strength.
The seismic provisions, such as horizontal bands at plinth, lintel, and roof levels, are mandatory in seismic zones III, IV, and V and should not be omitted.
Properly accounting for wall openings and providing required strengthening around them is crucial for structural integrity.