Shear wall is a structural system to counter the effects of lateral load .wind and sesmic loads are the common load that shear walls designed to carry.
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Shear wall is RCC wall used to prevent from wind and seismic loads. Lift shaft is designed as Shear wall. Separate foundation is provided for shear wall. We can't design all walls as shear walls as it will increase cost of construction. Different positions of shear wall should be tried for optimum design.