Analysis of bearing capacity of temporary columns in top down construction methods

Abstract

One of the methods of construction which are increasingly used in urban conditions is a "Top Down" method. This method of construction is suitable when constructing buildings with a larger number of underground floors. Construction of the building is done from top to bottom where the ceilings of a structure are used for shoring of the structure for pit protection. One of the important elements in this method are internal ceiling supports. In the design engineers tend to minimise the costs and dimensions of these supports. This leads to the problem of their stability and capacity. This paper presents the analysis of bearing capacity of steel pipe filled with concrete which is on the bottom end elastically wedged in a pile and on the upper end in a constructed cealing of the building.

Jedna od metoda gradnje koja se sve više primenjuje u gradskim uslovima jeste "Top Down" metoda. Ovakav način gradnje je pogodan kada se izvode objekti sa većim brojem podzemnih etaža. Konstrukcija objekta izvodi se odozgo na dole pri čemu se tavanicama objekta vrši razupiranje zaštitne konstrukcije temeljne jame. Jedan od bitnih elemenata kod ove metode jesu unutrašnji oslonci tavanica. Pri projektovanju teži se da koštanje, odnosno dimenzije ovih oslonaca budu minimalne. To dovodi do problema njihove stabilnosti i nosivosti. U radu se prikazuje analiza nosivosti stuba od čeličnih cevi ispunjenih betonom koji su sa donje strane elastično uklješteni u šip, a sa gornje strane u izvedenu konstrukciju objekta.