Demountable Frame Structure with an Elastically Embedded Diaphragm

Abstract

Precast reinforced concrete demountable column system with elastically mounted diaphragms inserted into frame sections developed within the TACR grant project [1] was verified by a pseudo-dynamic tests in the UTAM AV CR experimental facility. The experimental verification and theoretical analysis was aimed at identifying the stiffness characteristics and dynamic response of the “frame” section, including the evaluation of the effect of demountable joints while mounting the diaphragm on beams using elastic (rubber) bearings. The experimental verification was performed for three different diaphragm to beam connections made by a rigid screw connection and by a connection with elastic bearings with two different stiffness values. During the first phase of the experimental verification the structure was exposed to pseudo-dynamic loading by a hydraulic jack controlled by deformation or by amplitude and corresponding frequency of the jack. The absolute deformations of the structure as well as relative deformations between individual structural elements were monitored by means of linear deformation sensors. The force necessary for reaching these deformations was also monitored. In the second phase of the experimental campaign the natural frequencies and dampening characteristics were identified. Based on the obtained values, the stiffness and dynamic characteristics of the frame structure with three different types of the stiffening diaphragm connections were identified and were compared with numerical model. Theoretical analysis and results of experimental research proved the satisfactory resistance of the proposed multi storey building system.