Lateral load elements; stepwise [cut off]

Reading of the question: the end of the question is cut off in the scan, so it is read as: "List the elements of masonry structure resisting lateral loads. Describe the stepwise load path (design procedure) for lateral loads."

Elements resisting lateral loads

1. Shear walls: load-bearing masonry walls parallel to the lateral force (in-plane shear and rocking resistance).
2. Roof and floor diaphragms: rigid horizontal slabs that distribute the force to the shear walls.
3. Cross (transverse) walls, piers and buttresses: support the walls against out-of-plane bending.
4. RCC/timber bands and tie columns: give box action and tie the walls together.
5. Foundation and plinth band.

Stepwise procedure

1. Find the lateral force: the seismic base shear $V_B = A_h W$ (IS 1893 / NBC 105) or the wind load (IS 875 Part 3) on the walls and roof.
2. Distribute the base shear to the floor and roof levels in proportion to $W_i h_i^2$ (weight and height of each level).
3. Transfer the force from each diaphragm to the shear walls in proportion to their stiffness (rigid diaphragm) or their tributary area (flexible diaphragm).
4. Check each shear wall for in-plane shear stress $\tau = V/(L\,t)$ against the permissible shear stress $f_s = 0.1 + f_d/6 \le 0.5$ N/mm$^2$ (IS 1905 cl. 5.4.3).
5. Check overturning and the extreme-fibre stresses (axial plus bending), with no tension in the masonry.
6. Check each wall for out-of-plane bending, spanning vertically or horizontally, with a permissible flexural tension of 0.07 N/mm$^2$ (vertical bending, M1 mortar).
7. Provide bands, corner steel and connections to complete the load path to the foundation.

 Force -> Diaphragm -> Shear walls -> Foundation -> Ground
             (cross walls support walls out-of-plane)