Failure Modes and Seismic Strengthening Methods of Masonry Structures

Masonry buildings represent a large portion of the buildings around the world and in Iran especially in the small cities. Therefore seismic assessment and retrofit of masonry structures is becoming an important problem. Also historical structures are made of masonry materials. Masonry structures have poor seismic resistance and are the most vulnerable during an earthquake. To know about these weak points leads to chose appropriate method of strengthening. Modes of failure in masonry wall can be organized in two broad categories: in-plane failure, where loads act in the plane of the wall; and out-of-plane failure, where loads act perpendicular to the wall's face. Evidence of both types of failure can be found at all earthquakes, although out-of-plane failures are far more prominent. Also masonry infill walls can be found as interior and exterior partitions in reinforced concrete and steel frame structures. Since they are normally considered as architectural elements, the infill walls presence is often ignored by structural engineers. In this paper failure modes and several methods for retrofitting the masonry structures are discussed.

Keywords:

masonry structure , seismic retrofit , vulnerable