Q1: If the length of a wall on either side of a lintel opening is at least half of its effective span L, the load W carried by the lintel is equivalent to the weight of brickwork contained in an equilateral triangle, producing a maximum bending moment

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When the length of a wall on either side of a lintel opening is at least half of its effective span L, and the load W carried by the lintel is equivalent to the weight of brickwork contained in an equilateral triangle, it results in a configuration that induces a maximum bending moment on the lintel. This scenario creates a situation similar to a concentrated load being applied at the midpoint of the lintel span. The weight of the brickwork in the equilateral triangle is concentrated at the center of gravity of the triangle, which coincides with the midpoint of the lintel span due to the symmetrical arrangement. In structural analysis, a concentrated load applied at the midpoint of a simply supported beam generates a maximum bending moment at the mid-span. Similarly, in this scenario, the concentrated load effect from the equilateral triangle of brickwork creates a maximum bending moment at the midpoint of the lintel span. Therefore, by ensuring that the length of the wall on either side of the lintel opening is at least half of its effective span and distributing the load of the equilateral triangle of brickwork appropriately, the configuration maximizes the bending moment on the lintel, leading to efficient load distribution and structural performance.