Self-Centering Behavior of Unbonded,Post-Tensioned Precast Concrete Shear Walls

Self-centering ability of unbonded post-tensioned precast concrete shear walls has been attributed to the presence of post-tensioning force. However, the experimental results presented in this paper indicate that the post-tensioning force may completely die out during cyclic loading while the walls are able to retain their superior self-centering characteristic. Moreover, the analytical study presented in this article indicates that with proper configuration of end-anchorages for post-tensioned tendons, self-centering of post-tensioned walls can be achieved even when the post-tensioning force vanishes. This study also investigates the effects of tendon layout, tendon end-anchorage configuration, and external vertical load on the self-centering ability of unbonded precast concrete shear walls subjected to earthquake loading.     

Functional change as an indicator of transformation near the old city centre of Istanbul

Over time, the residential areas close to city centres have experienced change in their function and social structure. In Istanbul a functional and social change is also observed, especially in the residential buildings near the historical city centre. This study investigated this process of transformation through a research project conducted in the southern part of the Istanbul Historical Peninsula (old city centre) and documents the recent functional changes in this district. It also considers the role of tourism in the process of inner city transformation. On the basis of the data collected during the study, proposals are forwarded for the future development of the area.