Seismic response of horizontal concrete facade systems in reinforced concrete prefabricated buildings

The seismic performance of prefabricated, reinforced concrete (RC) structures with horizontal concrete façade systems typically used across Central Europe was investigated. Extensive static and dynamic experiments supported analytical and numerical research presented in the dissertation. Many tests were successfully simulated by newly defined numerical models. A basic in-plane response mechanism of the fastening system consists of three distinct stages: sliding with limited friction, contact with the panel causing an increase in stiffness of the connection and brittle failure. The top connections are the weakest components of the fastening system. Experimental observations during the shake table tests and extensive parametric study showed that the column drift along the single panel could measure capacity and demand on the fastening system. Various important parameters and their influence on the seismic response were analysed. The initial position of cladding connections significantly influences the responses and the drift capacity of the system. Thus, a proposal was made in the dissertation to improve the façade system based on providing more space for connections to slide. The influence of the façade system on the response of the main structure is small. It can be noticed only for very slender structures with small tributary mass. The response of the main precast structure could be reasonably well estimated with a current design approach. A relatively simple procedure for estimating the approximate demand on the façade system is given. At the end of the thesis, a numerical analysis and evaluation of a restrainer system were performed.Raziskan je bil potresni odziv AB-montažnih stavb z betonskimi vodoravnimi fasadnimi sistemi, ki se pogosto uporabljajo v srednji Evropi. Analitične in numerične študije, ki so predstavljene v doktorski nalogi, so bile podprte z obsežnimi dinamičnimi preizkusi. Številni testi so bili uspešno simulirani z na novo definiranimi numeričnimi modeli. Osnovni mehanizem odziva fasadnih stikov je sestavljen iz treh značilnih faz: faza drsenja, pri kateri se aktivira majhno trenje, stik s panelom, ki povzroči skokovito porast togosti stika, in krhka porušitev. Ugotovljeno je bilo, da so zgornji stiki najšibkejši člen pritrdilnega sistema. S preizkusi na potresni mizi in parametrično študijo je bil ugotovljen mehanizem odziva celotnega montažnega sistema z vodoravnimi paneli in analiziran vpliv panelov na odziv glavne montažne konstrukcije. Ugotovili smo, da lahko obremenitev in kapaciteto sistema stikov izrazimo s pomikom stebra na ravni panela. V okviru parametrične študije je bil analiziran vpliv različnih parametrov na potresni odziv panelov in konstrukcije. Pokazali smo, da je odziv vodoravnega fasadnega sistema odvisen predvsem od začetnega položaja stikov. Vodoravni fasadni sistemi imajo v splošnem majhen vpliv na odziv glavne montažne konstrukcije. Vpliv je opazen le ob zelo vitkih konstrukcijah z majhno maso povprečnega stebra. V nalogi je ovrednoten trenutni projektantski pristop, s katerim lahko razmeroma dobro ocenimo odziv glavne montažne konstrukcije. Podan je sorazmerno preprost postopek za približno oceno obremenitev fasadnega sistema. V zadnjem delu disertacije sta bili narejeni numerična analiza in presoja pridrževalce