- Practice · 6 marks
Check of a solid brick wall under gravity load
Short answer
Using H_eff=0.75×3.2=2.4 m, SR=2400/230=10.43, k_s=0.879, k_a=1.0, f_c=0.879 N/mm². Self-weight 13.98 kN/m, total load 133.98 kN/m gives stress 0.583 N/mm² < 0.879, safe. Maximum total load capacity = 202 kN/m.
A single-storey load-bearing brick wall is 230 mm thick and 3.2 m high (clear height between floor and roof slab). The RC roof slab bears over the full wall thickness on both sides and gives lateral and rotational restraint at the top, and the wall is fixed at the base. The basic compressive stress is N/mm². The slab transfers a working load of 120 kN per metre length of wall at the top, and the unit weight of masonry is 19 kN/m³. Using the IS 1905 method with from the table (SR 10 → 0.89, SR 12 → 0.84), check the wall and find the maximum load per metre it can carry.
Step 1: Slenderness
Lateral and rotational restraint at both ends gives :
, so OK.
Step 2: Stress reduction factor
Interpolate between () and ():
Step 3: Permissible stress
Per metre length, area m² m², so ; for bricks .
Step 4: Actual stress at base
, so the wall is safe (utilisation 66 percent).
Step 5: Maximum load
Allowable additional slab load .
Answer: Actual stress 0.58 N/mm² < 0.879 N/mm², safe. Maximum total load = 202 kN/m (slab load about 188 kN/m).
✓ Answer checked by Claude Sonnet 5.5
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