Institute for Concrete and Masonry Structures, Technical University Munich, Germany

Under horizontal loads, e.g. due to wind or earthquake actions, the distribution of the lateral forces to the several shear walls in multi-storey masonry structures is usually calculated assuming a linear-elastic behaviour. Though, with rising horizontal load levels and the associated eccentricities the compressed part and consequently the stiffness of the walls is reduced. The rate of the stiffness reduction of each wall depends on the vertical load level, the geometric properties and the position in the whole structure. To study theses effects, numerical investigations have been carried out on a spatial finite-element system. The RC-floor slabs were considered to remain uncracked and the vertical shear walls were described by a nonlinear material law. The interface between horizontal RC-slabs and the vertical masonry walls was assumed to be fixed as tension failure perpendicular to the bed joints was included in the material model of the masonry walls. The chosen finite-element-approximation enabled to cover shell deformations and also plate deformations. From the results, the changing distribution of the lateral loads to the shear walls and also the stress state in each wall was determined.