Structural Investigation of a Historical Masonry Arch Bridge under Far-Fault Earthquakes

In this research, it is aimed to observe a feature study around the assessment of static and dynamic productivity of a historical arch bridge (HAB) (Konjic Bridge (KB)) in view of dissimilar far fault earthquakes (FFEs). To explore the conduct of FFEs on KB, finite element model (F-E-M) of the KB is assembled and evaluated under various FFEs using ANSYS. Then, FFEs are considered as a result of their distinct, destructive velocity pulse characteristics. The maximum displacement values were found and correlated with the principal stresses and strains. At the conclusion of this investigation, it is observed that the arch of HAB has not more impact on the structural reaction of HAB. Furthermore, it is obviously detected that tensile stresses have not got the critic tensile strength (TS). Additionally, life cycle assessment (LCA) for HAB is also explored and observed that improving the longtime stress/strain values for HAB reduces the HAB life-expectancy dramatically

Köprü Zemin Etkileşiminin Deprem Etkisinden Dolayı Köprü Elemanlarında Oluşan Kuvvetlere Etkisi

Konferans Bildirisi-- İstanbul Teknik Üniversitesi, Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2017Conference Paper -- İstanbul Technical University, Theoretical and Applied Mechanical Turkish National Committee, 2017Bu çalışmada, yakın mesafeli deprem haraketlerinin köprü ayaklarında bulunan kazıklardaki yorulma davranışı üzerindeki etkisi incelenmiştir. Bu amaçla, Amerika Birleşik Devletlerindeki Guthrie Country Köprüsü üç boyutlu olarak modelenmiş ve sonlu elemanlar yöntemi uygulanarak ANSYS programında analizleri yapılmıştır. Üç boyutlu analiz sonuçlarından, yakın mesafeli deprem haraketlerinin, zemin boyunca kazık davranışı göz önüne alınarak, kazıkta meydana gelen yerdeğiştirmeler araştırılmıştır. Çalışma sonucunda, köprü-zemin etkileşiminin, integral köprü elemanlarında yakın mesafeli deprem haraketlerinden büyük oranda etkilediği saptanmıştır.In this study, the effect of soil bridge interaction on the magnitude of the internal forces in the integral bridge components due to near fault effects is studied. For this reason, 3-D Finite Element Model (FEM) of The Guthrie Country Bridge in USA is developed using the program ANSYS to numerically predict their fatigue performance in near fault regions. Using the results of the 3-D FEM, performance and displacement of steel piles in near fault regions are investigated. At the end of this study, the analyses results revealed that soil bridge interaction has significant effect on the magnitude of internal forces due to near fault regions in the components of integral bridges

Examination of masonry arch bridge’s life-cycle assessment under far-fault earthquakes

U radu je prikazano statičko i dinamičko ispitivanje ponašanja povijesnog zidanog lučnog mosta izloženog djelovanju potresa dalekog rasjeda. U prvom koraku izrađen je model konstrukcije primjenom metode konačnih elemenata uz pomoć programa ANSYS i SAP2000. Navedeno je napravljeno kako bi se ustanovilo mogu li se usporediti najveći mogući pomaci, primarna naprezanja i elastične deformacije. Iz svega navedenoga, ključni je element oštećenja gornja strana plohe. Nadalje, ocjenjivanjem životnog ciklusa zidanog lučnog mosta, uočene su povećane vrijednosti naprezanja i deformacija mosta čime se njegovo očekivano trajanje drastično smanjilo.The goal of this study is to examine the historical masonry arch bridge’s static and dynamic behavior using far-field fault earthquakes. The first step is to build a finite element model with ANSYS and SAP2000. This is done to see if the greatest possible displacements, primary stresses, and elastic strains compare. From above, the belt’s upper side appears to be vital for damage. Furthermore, a historical masonry arch bridge’s life cycle assessment is also researched and observed, which results in increased stress and strain values for the bridge, causing its expected life span to be drastically reduced

Entegral köprülerde çelik h-kazıkların düşük devirde yorulma performansı.

Integral bridges are jointless bridges where the superstructure is connected monolithically with the abutments. Due to seasonal temperature changes the abutments are pushed against the approach fill and then pulled away, causing lateral displacements at the top of the piles that support the abutments. This may result in the reduction of their service life due to low-cycle fatigue effects. In this research, both analytical and experimental studies are conducted to investigate the effect of thermal induced cyclic displacements/strains on the low cycle fatigue performance of steel H-piles at the abutments of integral bridges. First, a new cycle counting method is developed to determine the number and amplitude of large and small pile displacement/strain cycles due to seasonal and daily temperature fluctuations. Then, a new equation is developed to determine a displacement/strain cycle amplitude representative of a combination of a number of small and large amplitude cycles existing in a typical temperature induced displacement/strain history in steel H-piles of integral bridges. Then, nonlinear finite element models (FEMs) of the steel H-pile specimens used in the experimental part of this research study are developed using the computer program ANSYS. Next, FEM of these test specimens are subjected to a loading similar to that is used in the experimental testing. The main purpose of conducting such nonlinear analyses is to identify potential problems that may be encountered during testing and to improve the test apparatus if necessary. Low cycle fatigue tests are then conducted to investigate the fatigue life of steel H-piles subjected to thermal induced cyclic strains/displacements. The tests are designed to study the effect of several parameters, namely; (i) pile size (ii) equivalent length of the pile, (iii) orientation of the pile (strong axis or weak axis bending), (iv) small amplitude cycles (displacement history with and without small amplitude cycles), iv) amplitude of the small displacement/strain cycles with respect to that of large displacement/strain cycles and (vi) the magnitude of the axial load applied on the pile. Furthermore, nonlinear FEMs of the steel H-pile specimens are developed using the program ANSYS to numerically predict their low cycle fatigue performance under cyclic thermal induced displacements/strains. .Ph.D. - Doctoral Progra

Effect of longitudinal stiffeners on the flanges to improve the low cycle fatigue performance of steel H-piles

In this study, the effect of stiffeners on the low cycle fatigue life of steel H-piles in integral bridges is investigated to prevent local buckling occurring at high strain amplitudes. For this purpose, experimental testing of a number of regular and stiffened steel H-piles under cyclic displacement reversals is conducted. Then, to compare experiment results with the finite element model for the HP220x57 steel specimen, finite element model is constructed similarly according to actual HP220x57 steel specimen in the test set up

Low-cycle fatigue in steel H-piles of integral bridges; a comparative study of experimental testing and finite element simulation

Integral abutment bridges (IABs) are those bridges without expansion joints. A single row of steel H-piles (SHPs) is commonly used at the thin and stub abutments of IABs to form a flexible support system at the bridge ends to accommodate thermal-induced displacement of the bridge. Consequently, as the IAB expands and contracts due to temperature variations, the SHPs supporting the abutments are subjected to cyclic lateral (longitudinal) displacements, which may eventually lead to low-cycle fatigue (LCF) failure of the piles. In this paper, the potential of using finite element (FE) modeling techniques to estimate the LCF life of SHPs commonly used in IABs is investigated. For this purpose, first, experimental tests are conducted on several SHP specimens to determine their LCF life under thermal-induced cyclic flexural strains. In the experimental tests, the specimens are subjected to longitudinal displacements (or flexural strain cycles) with various amplitudes in the absence and presence of a typical axial load. Next, nonlinear FE models of the tested SHP specimens are developed using the computer program ANSYS to investigate the possibility of using such numerical models to predict the LCF life of SHPs commonly used in IABs. The comparison of FE analysis results with the experimental test results revealed that the FE analysis results are in close agreement with the experimental test results. Thus, FE modeling techniques similar to that used in this research study may be used to predict the LCF life of SHP commonly used in IABs

Structural Investigation of a Historical Masonry Arch Bridge under Far-Fault Earthquakes

In this research, it is aimed to observe a feature study around the assessment of static and dynamic productivity of a historical arch bridge (HAB) (Konjic Bridge (KB)) in view of dissimilar far fault earthquakes (FFEs). To explore the conduct of FFEs on KB, finite element model (F-E-M) of the KB is assembled and evaluated under various FFEs using ANSYS. Then, FFEs are considered as a result of their distinct, destructive velocity pulse characteristics. The maximum displacement values were found and correlated with the principal stresses and strains. At the conclusion of this investigation, it is observed that the arch of HAB has not more impact on the structural reaction of HAB. Furthermore, it is obviously detected that tensile stresses have not got the critic tensile strength (TS). Additionally, life cycle assessment (LCA) for HAB is also explored and observed that improving the longtime stress/strain values for HAB reduces the HAB life-expectancy dramatically