Lateral strength of multi-storey masonry walls with openings and reinforcements

Abstract eng:
Aim of the paper is to present a simple procedure to evaluate the out of plane and the in-plane strengths of the reinforced masonry multistory walls with openings, the main resistant structural elements of typical historic masonry buildings. The wall is considered reinforced by steel ties and lintels, these last placed over the openings, under the architraves connecting the wall piers. The paper analyses both the out of plane and the in plane strength of the wall. The Heyman rigid in compression no tension model for the masonry material is assumed to establish a simplified model of the masonry wall; at the same time steel ties and masonry architraves will sustain only tensile or compressive forces. Further, the steel lintels placed over the wall openings will exhibit only bending strength. The basic failure in-plane mechanism of the multistory masonry wall is the sideways mechanism with toe rotation of piers. The lateral strength of the wall depends on two different effects: the first is due to lifting of the vertical dead loads during the pier rotation ,effect common to all masonry structures, as in the masonry arch; the second is due to the plastic bending developing in the steel lintels. By means Limit Analysis the kinematical multiplier of the horizontal forces can be easily evaluated. More difficult is to control that the kinematical multiplier could be the real collapse load of the wall. The redundancy of the internal horizontal stresses in the horizontal connections requires the solution of a system of inequalities. The solution procedure shows that, among all the various unknown, at least one will be equal to zero. This statement, together with the observation that the stress distribution in the connections can be assumed linearly varying with the height, solves the problem. The bending strengths of the steel lintels have significant relevance and they have to be chosen with accuracy in order to avoid local failures in advance to the overall failure mode of the multistory wall. Some examples are given and discussed in the paper.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket