Vol.8, No 2, 2010 pp. 225 - 234
UDC
624.01(045)=111
DOI:
10.2298/FUACE1002225Z
REDISTRIBUTION OF THE INFLUENCES IN SYSTEMS WITH SEMI-RIGID JOINTS ON ELASTIC FOUNDATIONS
Dragan Zlatkov, Slavko Zdravković, Marina Mijalković,
Biljana Mladenović, Tomislav Igić
University of Niš, Faculty of Civil Engineering and Architecture, Serbia
Most often, in the case of typefied prefabricated systems, foundations are designed and constructed as prefabricated elements as well. When the structure is exposed to high intensity loading and founded on a weak soil, beam foundations are often used instead of pad foundations. Beam foundations, stiffening girders, as well as beams which support the façade elements or partition walls, are treated as beams on elastic foundations, while joint of these girders to pad foundations or vertical support elements of a precast structure can be treated as semi-rigid. Modeling of systems with semi-rigid joints on elastic foundations, for different levels of rigidity of connections, is illustrated by an example of a frame under static loading. On the basis of the results of the calculation carried out in this paper, it is evident that taking into account the elastic foundations of the member and the corresponding degree of fixation of the member on this foundations significantly affects the magnitude of the forces in the cross-sections of the member, and on the redistribution of influences in the entire structure. Yet, the foundations-and-soil interaction exerted the highest influence on the magnitude of the stress in the foundation structure itself.
Key words:
precast structure, semi-rigid connection, redistribution of influences.
PRERASPODELA UTICAJA KOD SISTEMA SA POLUKRUTIM VEZAMA NA ELASTIČNOJ PODLOZI
Kod tipskih montažnih sistema često se i temelji projektuju i izvode kao montažni. Kada su opterećenja konstrukcije većeg intenziteta ili je tlo na kome je izvršeno fundiranje slabije nosivosti, umesto temelja samaca koriste se trakasti temelji. Trakasti temelji, grede za ukrućenje, grede koje nose fasadne elemente ili pregradne zidove tretiraju se kao grede na elastičnoj podlozi, a veze tih greda sa temeljima samcima ili vertikalnim nosećim elementima kod montažnih objekata mogu se smatrati polukrutim. Modeliranje sistema sa polukrutim vezama na elastičnoj podlozi, za različite stepene uklještenja, ilustrovano je primerom rama izloženog statičkom opterećenju. Na osnovu rezultata proračuna sprovedenog u ovom radu, evidentno je da uzimanje u obzir elastične podloge štapa i odgovarajućeg stepena uklještenja štapa na toj podlozi znatno utiče na veličinu sila u presecima tog štapa, kao i na preraspodelu uticaja u čitavoj konstrukciji. Ipak je najveći uticaj interakcije temelja i tla na veličinu naprezanja u samoj temeljnoj konstrukciji.
Ključne reči:
montažne konstrukcije, polukrute veze, preraspodela uticaja