Assessment and Retrofit of the Bridge over Kouris River, Cyprus

12th International Conference on Structural Analysis of Historical Constructions, 2021

This study assesses the earthquake performance of a historical masonry arch bridge in Aizanoi ancient city, which is located in the mid part of Turkey near Kütahya. Aizanoi was the capital of the territory called Aizanitis, located in the area of Phrygia. Historians agreed that Roman settlement in this area started in 3 rd millenium BC. The structure is made of stone and has five arches of 5.40m, 6.70m, 7.30m spans. Rise of the arches are varying from 2.70m to 3.65m. Restoration works have completed in 2018. Before the restoration works have been started the bridge was used for vehicles, even for heavy trucks. Today the bridge is using only for pedestrians. After a detailed site investigation, material characterisation and soil tests were performed, ambient vibration test was carried out on site, by placing accelerometers at several points on bridge span to capture dynamic properties of the structure. Different methods such as Frequency Domain Decomposition, SSI were used to extract the experimental natural frequencies, mode shapes, and damping ratios from these measurements. Experimental results were compared with those obtained by the linear finite element analysis of the bridge. Good agreement between mode shapes was observed in comparison, though natural frequencies disagree by 8-10%. The boundary conditions of the linear finite element model of the bridge were adjusted such that the analytical predictions agree with the ambient vibration test results. According to the total strain crack material model, the calibrated linear FE model was extended into a nonlinear model then Nonlinear Static Pushover analyses of the bridge along longitudinal and transversal directions were performed. Obtained results are in good agreement with previous case studies' results. In order to compare collapse load of the bridge with pushover analysis results, kinematic limit analysis procedure is used to assess longitudinal and transverse seismic capacities. The capacity curves are obtained by means of limit analysis approach. The study is aimed to identify on one hand the horizontal load multiplier that activates the kinematic mechanism, on the other hand the collapse displacement. The numerical results of the structural capacity so found have been compared with the results available in literature and acceptable agreement of the results have been obtained.

2014

Seismic retrofitting of existing bridges, aimed at enhancing their safety level under earthquake conditions according to current design standards, is often a challenging task. When designing the strategy for seismic retrofitting, in fact, the practitioner have often to face remarkable limitations to the possible interventions, mostly due to the geometry of the original structures and to construction site accessibility issues. A meaningful example of this task is represented by the concrete bridge over the Tanaro and Bormida rivers of the A21 Italian highway between the cities of Turin, Alessandria and Piacenza, managed by Satap S.p.A in Turin. The overall bridge is characterized, in fact, by three different structural types consisting of: (a) a box girder deck, (b) a deck supported by regular r.c. beams and (c) a deck supported by p.c. beams. The analysis of the seismic vulnerability of the bridge in its „as-built‟ configuration has been carried out according to the current Italian ...

Challenge journal of structural mechanics, 2021

A large proportion of road and railway bridges, present in Turkey served for many years, have been completed their service life or will soon. Continuing safety and sustainability of these bridges under traffic loads have been of great increasing importance to roadway and railway transportation line to be continuous servicing. In addition, the demolition and reconstruction of bridges that have reached the end of their service life or are nearing completion will have a negative impact on the country's economy. All of these requirements' detailed examination of bridges in order to provide economical and safe service, considering current vehicle loads and earthquake loads. The Mahmutçavuş Bridge is investigated as a simply supported continuous composite roadway bridge at this work. The finite-element model of the bridge is constituted by site investigation and measurement. Different truckloads using for the design of the bridge are determined, and static analysis of the bridge is conducted. Seven earthquake records are scaled for two different earthquake design spectrums. The nonlinear time-history analyses are conducted, considering Δ-δ effects. The performance of the bridge for varying truckloads and earthquake loads is investigated, and results are discussed in detail.

The Retro TA project funded by the European commission within the Series-project aims at studying the seismic behaviour of existing reinforced concrete (RC) bridges and the effectiveness of innovative retrofitting systems. The research activity focuses on old bridges, designed chiefly for gravity loads. Towards this aim, the seismic vulnerability of an old Italian viaduct with portal frame piers (Rio Torto Viaduct) is evaluated and an isolation system is designed using both yielding-based and slide spherical bearings. Some results of predictive numerical analyses, both for “as-built” and “isolated” configuration are illustrated and discussed. The work is subdivided in two parts: the present paper is devoted to the analysis of the “as-built” configuration. The structure is assessed through dynamic analyses. To do so, the Italian guidelines for the seismic assessment of existing bridges, proposed within the Reluis research program (2005-2008), are employed. Progressive damage using natural records is estimated and failure modes of the system components are accurately analyzed. The assessed systems is found substandard; it is thus deemed necessary to utilize an adequate retrofitting system such as seismic isolation.

The project proposal is about the Reinforced Concrete Maluos Bridge situated along the Bukidnon-Davao City Road at Kabalansihan, Kitaotao, Bukidnon. The said project is designed using the analysis for reinforced concrete. Certain parameters for the reinforced concrete structure has been considered in order to attain the objectives formulated in the project for better results. Accordingly, the factors and parametric awareness that may affect the integrity of the bridge was considered. The elements of the bridge, the materials and its corresponding properties, the different types of loading including impact, and the different design assumptions has been rigorously considered. Portland cement, coarse and fine aggregates, water, admixtures, and deformed bars are materials that made up the reinforced concrete has been identified and defined according to its properties and specifications as base on theoretical codes. Compressive and tensile strength, stress-strain curve, Modulus of Elasticity, creep and shrinkage, and quality control of both concrete and the reinforcing bars were further elaborated. Next, the strength design method, NSCP designs assumptions and safety provisions, loads and load combinations as based on AASHTO and NSCP, and software programs used in the calculations and design were discussed thoroughly. Under the plans and specifications were the architectural and structural drawings which were shown. Such architectural drawings includes the top view, general elevation, and isometric view of the bridge while on the structural drawings includes the detailed drawings of the beam, slab, barriers, and footings. Followed by the plans and specifications are the results and discussion of the project. This is where the important parameters and factors in the analysis and assumptions of the design was discussed. After the analysis is the conclusion and recommendation for the project. The bridge is designed to support an MS18 (H20-44) vehicle. The bridge is composed of eight reinforced concrete beam/girder with a dimension of 350mm x 620mm. Beams located on both ends, supporting sidewalk live loadings, has 5-25mm reinforcements, while beams supporting the roadway has 11-25mm reinforcements. Moreover, it is composed of a 200mm-thick slab with a 125mmthick wearing course made of asphalt. Lastly, a spread footing with a dimension of 9.54m by 3.5m with a thickness 600mm and with a 25mm diameter reinforced bars has been designed. More detailed and elaborated results are presented in Chapter 5.

Bridges are among those types of structures which their serviceability under service loads and after earthquakes is extremely important. Tehran is located in a region with a high risk of seismic activity, so it seems necessary to conduct visual inspection and field observations throughout this city in order to make technical evaluation and assess the structural and non-structural weaknesses and defects in vital urban structures such as the bridges. On this basis, this study assessed the structural condition and non-structural weaknesses of the RC bridge on the Hakim-Kan river intersection in Tehran, and presented basic strategies for its maintenance and seismic retrofit.

2nd Istanbul Bridge Conference, 2016

Turkey having a great civilization history inherited many cultural heritage structures such as mosques, bridges, baths and madrasahs. Historical bridges constitute a significant part within these heritages and most of such structures were constructed as masonry stone arch bridges and so the preservation and transferring them to the next eras becomes an important issue. To contribute protection and rehabilitation of stone arch bridges in structural way, historical Justinianus Bridge, situated on the Sakarya River of Turkey and made of stone arch form, was investigated structurally. It is heritage from ancient Roman Era. Several damage, deterioration, deficiencies are observed on the structural system in the current state. 3D structural modeling of the bridge was performed by Finite Elements Modeling (FEM) through DIANA software. Separate modeling of arches, spandrel walls and backfill were considered with different material properties to consider interaction between such members. Modal characteristics were investigated by modal analyses. Structural analyses were carried out under self-weight/dead loads, live loads and seismic loading. Structural response and behavior of the bridge were investigated and discussed in terms of normal and shear stress distribution, mode shapes as well as displacements. It was aimed to analyze these damages which have occurred under gravity and lateral loading with engineering methods and to evaluate results of analysis for restoration in this study. The bridge has experienced many earthquakes since it was built, besides environmental and aging effects. Currently, various such as stone and masonry cracking, material loss and vegetation have been observed on the bridge.

Bridge Maintenance, Safety and Management, 2012

The existing stock of road and railway bridges in Italy and in most European countries frequently exhibits insufficient performances, both in terms of structural safety and functionality, compared to the current demands coming from modern structural codes, transportation systems and necessity of reducing the costs of maintenance. Quick and reliable methodologies are then needed to assess the specific vulnerability of any bridge typology, in any possible environmental and operating conditions. In the first part of the paper the application of such type of methodologies to both road and railway transportation infrastructure in Italy is described showing that, e.g., masonry arch bridges are usually quite robust structural systems, r.c. bridges generally present durability problems and are vulnerable to seismic actions, steel bridges, other than presenting durability problems, are particularly vulnerable to fatigue. Typical retrofitting interventions considered in these studies are also briefly presented. In the second part of the work significant case studies of retrofitting interventions are in more detail described, focusing on four existing r.c. bridges, which represent an homogeneous set, all of them being part of the post-II nd World War reconstruction on the Adige River (the second longest river in Italy). These bridges are examples of some of the most usual typologies adopted in that historic period, and the defects they evidenced after fifty years of service life were typical of these kind of structures, being often the consequences of a poor maintenance and the lack of durability rules in the original design. The refurbishment interventions are presented outlining a methodological approach, which takes into account the typological characteristics of the structure, the state of maintenance, the functional requirements and the environmental aspects connected to the repair and strengthening system.