Çok katlı çelik sanayi yapılarında taşıyıcı sistem seçimi ve boyutlandırma prensipleri

Abstract

Ağır ekipman yüklü çok katlı çelik sanayi yapılarında taşıyıcı sistem secimi ve konsrtikttif prensiplerle ilgili kriterlerin ele alınması ve bunların uygulamadan alınmış iki örnek Üzerinde incelenmesi çalışmanın esasını oluş turmaktadır. Ayrıca birinci örnekte yapının deprem ha linde Uc boyutlu statik ve dinamik coztimleri yapılmış tır. Çelik sanayi yapılarındaki taşıyıcı sistemler» rijit çerçeveli sistemler, dUsey kafes kirişli sistemler ve karma sistemler olmak Üzere Uc grup altında incelenerek, taşıyıcı sistemlerin seçimine etki eden faktörler ele a- lmmıstır. Geniş kullanım alanına sahip olan eleman en- kesitleri ve bir -esimler verilmiş olup, konsrtikttif esas lara deginilmeye çalışılmıştır. Birinci örnekteki taşıyıcı sistemin coztimtlnde matris- deplasman yöntemine göre hazırlanmış bir bilgisayar programı kullanılmıştır. Statik cöztim Uç yUkleme olarak yapılmıştır. Dinamik çözümde yapının ilk bes modu esas alınmış olup, mod sUper pozisyonu metoduna göre kesit te sirleri hesaplanmıştır. Bilgisayar çıkışlarından elde e- dilen kesit tesirleri kullanılarak statik ve dinamik çö- zUmleri arasında bir mukayese yapılmıştır.

Multi-Storey Industrial Steel Structures With Heavy Equipments In this study, systems o-f multi-storey industrial steel structures with heavy equipments have been exami ned on two examples. For this purpose, as the first step industrial steel structure systems have been classified into three main groups which are rigid-frame systems, braced-frame systems and systems composed of rigid and braced frames. Connections and cross section types of structural members used and applied widely in industrial steel structures have also been given. The structure in the first example have been analised for earthquake ef fects by using static and dynamic methods. In the static method, equivalent static forces have been used. Spect rum curve for dynamic analysis have been obtained from the specification for structures to be built in earthqu ake zones. Both anlyses have been performed by using a computer program which can execute three dimensional structural analysis. At the end of the study, dynamic and static solutions have been compared to each other and come to some conclusions. In the first example, the structure has a framework which consists of rigid and braced frames. In the struc ture, there are four axes in both directions and twelve floors; the height of the structure is 3*3.S5 meters and dimensions in the plane are 16.50 and 17.00 meters. Be am-column connections of internal axes were designed to carry moment, shear and axial forces, since they are com ponents of the rigid frame. Rigid connections were built using continous fillet- weld. In beam- column connections of external axes were designed to carry only shear and axial forces, by using bolts- regulai - course-thread. The framework of the structure in the second example consists of only braced frames. All beam-column connec tions were designed to transfer only shear and axial forces. The structure has four and six axes in two di rections, respectevely. Steel skeleton of the structure rises up +11.500 level between fifth and sixth axis, ot her axes +34.000 level. In beam- column connections, high strength bolts were used. The bracings elements in both structures were chosen in such a way so as to provide stability of the steel skeletons and to safely tranfer wind and earthquake lo ads down to foundations. In the applications of static method to the analysis of the structure in the first example, equivalent static forces for earthquake effects have been used. The analy sis have been performed considering three load conditi ons. Spectrum curve used in the dynamic analysis which is defined below, have been obtained from the specification for structures to be built in earthquake zones. 1.35K... lN ? K NN * < D, D. N The dynamic analysis options of the program include the following: Steady State Analysis Eigenvalue Analysis Response Spectrum (Seismic) Analysis In response spectrum analysis, the dynamic equilibri um equations associated with the response of a structure to ground motion is given by, MÜ+CÛ+KU=MÜ_ where, Q M is the mass matrix, C is the damping matrix, K is the stiffnes matrix, Ü is the ground acceleration, VIII Ü is the structural acceleration, Û is the structural velocity, U is the structural displacement. The computer program solves this system of equations using the mode superposition response spectrum approach. The ground exitation can occur simultaneously in three directions, namely, any two mutually perpendicular directions in the X-Y plane and in the Z direction. The two directions in the X- Y plane are de-Fined as 1 and 2 where direction 1 is de-Fined by the angle counterclockwise from the global X axis. measured z-i rGLOBAL REFENCE AXIS The spectrum curves are defined by digitized points of time period vs spectral acceleration. To get the maximum displacements and member -Forces, first the modal responses associated with a particular direction of ex citation are calculated. The modal responses are then combined using the complete quadratic combination tech nique. The total response is then calculated by summing the response from the three directions by the square root of sum of the squares (SRSS) method. At the end of the study two structural systems which differ in formations of the skeleton have been analised and obtained the conclusions below: IX Rigid frame systems are quite suitable for placing of equipments and horizontal and vertical mechanic axes in the structure. But they are generally expensive solu tions since wind and earthquake loads are carried by on ly rigid frames. Braced frame systems play an important role in the multi- storey industrial steel structures. The wind and earthquake loads acting on the structures with braced frames are carried by bracings and so, the structure members are able to be chosen more economically. Locations of the bracing elements are determined in the way so as not to restrict function-areas of the equ ipments in the structure with braced frames. In the last part of this study the static and dynamic solutions obtained from the computer have been generally compared to each other and the general conclusion below has been obtained: The column moments in dynamic solution are bigger than the column moments in static solutions. The axial forces in static solutions are bigger than the axial forces in dynamic solutions.