Simulation of earthquakes on strengthened masonry walls: photogrammetric determination of kinematic shape changes

摘要

Abstract: In cooperation with the firm HILTI AG in Schaan the Swiss Federal Laboratories for Materials Testing and Research (EMPA) in Dubendorf, Switzerland is carrying out tests on masonry walls. The goal of these tests is to post-strengthen such walls in seismically endangered zones through the use of fiber- based composites. During the loading, the 3-D deformation behavior of the wall is determined. Each brick is provided with two measurement points. During the measurement phase the masonry wall deforms by up to 0.04 mm due to relaxation. Given a required deformation resolution of at least 0.04 mm, it is therefore necessary to employ a measurement technique that accurately and rapidly ascertains the wall condition in 3-D. In cooperation with the Institut fuer Photogrammetrie und Bildverarbeitung Technische Universitaet Braunschweig it was possible for the first time to employ five large-format Rollei LFC recording cameras synchronously for the deformation measurement. A spatial reconstruction of the wall shape was possible with an average standard deviation of 0.02 mm for the object coordinates in the plane of the wall, resp. 0.03 mm perpendicular to the wall. !4