An Algorithm to Justify the Design of Single Story Precast Structures

Abstract

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.

A Code Compatible Approach to Justify the Seismic Design of Simplified Structures

“… Several more checks has been added to the flow chart presented in [15] to have more refined one for controlling the sufficiency of sectional ductility needed to provide the required displacement ductility and to check the allowable tip rotations to keep the top beams stable in their original position and check for the overall stability of the columns. The algorithm proposed may be supported depending on new research in the field of defining reasonable limits for tip rotations and loss of safety against overall stability of the structure.…”

“…It will be assumed that the flexural EI, and shear GF', rigidities of the column are both constant along the height of the element. Since the stiffness coefficients of such a member can be derived easily, the case with variable EI and/or GF' can be handled easily as well [15,16,17].…”

“…Shortly the ratio of these two expressions yield the following formula ( ) (15) The graphical representation of this ratio is presented in …”

Slope Deflection Transfer Matrix Method for Continous Beams

“…The Slope Deflection Method, which is one of the classical methods used in structural analysis, has been taken part in the literature [17] [18] [19] [20].…”

Betonarme Binaların Mevcut Deprem Performansının Belirlenmesi İçin TBDY-2018’ de Önerilen Doğrusal Hesap Yönteminin Uygulanması Üzerine Bir İrdeleme

“…İkincisi, "kesin çözüm" olarak kabul edilen ve detaylı üç boyutlu modelleme ile doğrusal olmayan analizin yapıldığı ETABS yazılımıdır[5]. Üçüncü yazılım ise düzlem sistemlerin doğrusal ve doğrusal olmayan analizlerini yapabilen DC2B yazılımıdır[6]. Deprem ivme kayıtlarının seçimi ve ölçeklendirilmesi Zaman tanım alanında doğrusal olmayan analizlerde kullanılan deprem yer hareketlerinin seçimi, TBDY-2018 uyarınca, mevcut yapının bulunduğu bölgenin depremselliği, zemin sınıfı, faylanma mekanizmaları ve fay sistemlerine olan mesafeleri dikkate alınarak yapılmıştır.…”