The purpose of this study is first to determine the conditions for excessive torsional irregularity and then to discuss the validity of code provisions. A parametric investigation is performed on six groups of typical structures with varying shear wall positions, story, and axis numbers. It is found that torsional irregularity coefficients increase as the story numbers decrease, i.e., maximum irregularity coefficients occur for single-story structures. They reach maximum values when the asymmetrical shear walls are placed as close as possible to the centers of mass. However, the results obtained for floor rotations are quite contradictory. A new provisional definition for torsional irregularity coefficient based on floor rotations is proposed.

An attempt to estimate the displacement demands of precast cantilever columns has been presented here. The purpose of the findings presented is to set up a more reliable design philosophy based on dynamic displacement considerations instead of using acceleration spectrum based design which initiates the action with unclear important assumptions such as the initial stiffness, displacement ductility ratios etc. The sole aim of this chapter is to define a procedure for overcoming the difficulties rising right at the beginning of the traditional design procedure.For that purpose first 12 groups of earthquake records cover the cases of far field, near field, firm soil, soft soil possibilities for 2/50, 10/50 and 50/50 earthquakes with minimum scale factors are identified associated to the present fundamental period of structure. And they are reselected for each new period of structure during the iterative algorithm presented here and they are used to remove the displacement calculations based on static consideration. Nonlinear time history analysis (NLTHA) are employed within the algorithm presented here which takes into account the strength and stiffness degradations of structural elements and the duration of records which are ignored in the spectrum based design philosophy.

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One of the essential concerns in railway systems is the lifetime of rail tracks. The safety of rail fastening systems plays a significant role in rail track longevity. A standardized laboratory test procedure is required to be followed to evaluate the performance of rail fastening systems on the European railways according to EN 13146 standard series. In this study, longitudinal rail restraints and pullout resistances were experimentally determined following EN 13146-1 and EN 13146-10, respectively. Two different types of prestressed concrete sleepers (namely B320 type and B70 type) having the same concrete quality, design axle load, and design speed but different dimensions and fastening systems were used in the experimental studies. All specimens used in this study were seen to satisfy the conditions given in the standards. It was also observed that the fastening system used in B320 type prestressed concrete sleepers results in slightly higher axial load and pull-out load capacities.

An attempt to find out the most probable displacement demands of precast cantilever columns has been presented here. The purpose of the findings presented is to set up a more reliable design philosophy based on dynamic displacement considerations instead of using acceleration spectrum based design which initiates the action with unclear important assumptions such as the initial stiffness, displacement ductility ratio etc. The sole aim of this paper is to define a procedure for overcoming the difficulties rising right at the beginning of the traditional design procedure. For that purpose first 12 groups of earthquake records cover the cases of far field, near field, firm soil, soft soil possibilities for 2/50, 10/50 and 50/50 earthquakes with minimum scale factors are identified associated to the present fundamental period of structure. And they are reselected for each new period of structure during the iterative algorithm presented here and they are used to remove the displacement calculations based on static consideration.Nonlinear Time History Analysis (NLTHA) are employed within the algorithm presented here which takes into account the strength and stiffness degradations of structural elements and the duration of records which are ignored in the spectrum based design philosophy.