Blast Load Capacity of Highway Bridge Columns
| Autor: | Lukić, Sanja |
|---|---|
| Přispěvatelé: | Draganić, Hrvoje, Varevac, Damir, Radić, Ivan, Trogrlić, Boris |
| Jazyk: | chorvatština |
| Rok vydání: | 2023 |
| Předmět: | |
| Popis: | Armiranobetonski mostovi su rasprostranjeni diljem svijeta i od velike su važnosti za prometnu infrastrukturu i svakodnevne aktivnosti. Stoga ne čudi da su u posljednje vrijeme atraktivna meta terorističkih napada. Najkritičniji element mosta je stup jer njegovim urušavanjem, cijela konstrukcija gubi nosivost. Više od 50 % izvršenih terorističkih napada je izvršeno eksplozivnim napravama, a najučestaliji scenarij napada na mostove je eksplozivom postavljenim u automobil ispod rasponske konstrukcije mosta u blizini stupa. Na temelju pregleda projekata državnih arhiva Hrvatskih cesta i Hrvatskih autocesta izdvojeni su najučestaliji oblici armiranobetonskih stupova. Nakon preliminarnih numeričkih simulacija 9 oblika stupova u Ansys Autodyn programu, izabran je stup razvedenog pravokutnog poprečnog presjeka, označen kao P6. Stup P6 ima najmanji poprečni presjek, zadržava skoro najveće tlakove na prednjoj plohi u usporedbi s ostalim presjecima, najučestaliji je na osječkoj obilaznici i dimenzioniran je prema Jugoslavenskom standardu. Prema tome, glavni cilj ove doktorske disertacije je bio određivanje otpornosti izabranog stupa na pretpostavljeni scenarij napada eksplozivnom napravom. Eksperimentalno ispitivanje je provedeno u suradnji s Hrvatskom vojskom koja je osigurala eksploziv, prostor za provedbu eksperimenta i osoblje za rukovanje eksplozivom. U doktorskom radu je osmišljen koncept eksperimentalnog ispitivanja, a nakon provedbe eksperimentalnih ispitivanja, dana je katalogizacija oštećenja stupova prema razinama oštećenja te je zaključeno kako stup ima dovoljnu otpornost na djelovanje pretpostavljene količine eksploziva koja stane u automobil srednje veličine. Zatim su na temelju izgleda oštećenja napravljeni i kalibrirani numerički modeli u Ansys Autodyn programu koji će poslužiti za buduće analize stupova nadvožnjaka pri djelovanju eksplozije. Reinforced concrete bridges are common all over the world and are of great importance for transport infrastructure and everyday life. Therefore, it is not surprising that they have recently been an attractive target for terrorist attacks. The most critical element of the bridge is the column because if it collapses, the entire structure loses its load-bearing capacity. More than 50% of terrorist attacks have been carried out with explosive devices, and the most common scenario in attacks on bridges is the placement of explosives in a car under the span structure of the bridge near the column. Based on a review of the State Archives of Croatian Roads and Croatian Highways projects, the most common forms of reinforced concrete columns were filtered out. After preliminary numerical simulations of 9 column shapes in Ansys Autodyn software, a column with a branched rectangular cross-section was selected, designated as P6. Column P6 has the smallest cross-section, retains almost the highest pressures on the front side compared to the other sections, is the most frequent on the Osijek bypass and is dimensioned according to the Yugoslavian standard. The main objective of this doctoral thesis was to determine the resistance (load-bearing capacity) of the selected column to the assumed scenario of an attack with an explosive device. The experimental test was conducted in cooperation with the Croatian Army, which provided the explosives, the space for the experiment and the personnel to handle the explosives. In the doctoral thesis, a concept for experimental tests was developed. After the experimental tests were carried out, the damage to the column was catalogued according to the degree of damage, and it was concluded that the column sufficiently withstood the impact of the assumed amount of explosive that would fit in a medium-sized car. Subsequently, numerical models were created based on the damage pattern and calibrated in the Ansys Autodyn software, which will be used for future analyses of overpass columns under blast loads. |
| Databáze: | OpenAIRE |
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