Σεισμική συμπεριφορά ξηρολιθοδομής

Group Leader: Paulo Lourenco, University of Minho, Portugal

Preservation of the architectural heritage is a fundamental issue in the cultural life of modern societies. In recent years, large investments have been concentrated in this area, leading to development in the areas of inspection, non-destructive testing, monitoring and structural analysis of monuments. Nevertheless, understanding, analyzing and repairing historical constructions remains one of the most significant challenges to technicians.
The main objective of this research project is the understating of dry joint masonry mechanics, under biaxial loading through experiments. This type of masonry is a representative configuration of large number of existing monumental structures, which are made of dry stone joints or exhibit no tensile strength at the joints due to weathering. The obtained experimental results will be used for the calibration of sophisticated numerical methods based on micro and macro modeling, in order to reproduce the observed experimental behavior and for parametric studies for providing guidelines for practitioners.
A series of shaking tests will be performed on dry masonry specimens to examine the behavior of those walls under seismic loading. First, a set of tests will be carried out using different pre - compressive vertical stresses in order to examine the influence of compressive load. Then, the internal arrangement of masonry units (sawn, hand-cut and irregular units) in the global response of the walls will be examined under in plane cycling loading. Finally a series of tests with three leaves masonry walls will be performed applying in plane and out of plane base acceleration. The types of masonry that are going to be tested are shown in Figure 1, while in Figure 2 the shaking table experimental set-up is depicted.

Dry stone masonry wall
Irregular stone masonry wall
Rubble masonry stone wall
Three leaf masonry stone wall
Three leaf masonry irregular stone wall
Figure 1. Types of masonry
Figure 2. Shaking table experimental set-up.

Preliminary static tests have already performed during ECOLEADER. In Figure 3 the shear testing apparatus is shown. The two walls were tested under recyclic imposed horizontal displacement, while the vertical load was kept constant without any variation through out the test. The crack pattern of stone masonry is shown in Figure 4

Figure 3. Static tests - experimental set-up.
Figure 4. Crack pattern of wall.