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Assessment of a concrete arch bridge using static and dynamic load tests
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Assessment of a monumental concrete arch bridge with a total length of 210 meters having three major spans of 30 meters and a height of 65 meters, which is located in an earthquake-prone region in southern part of the country is presented in this study. Three-dimensional finite element model of the bridge was generated using a commercially available general finite element analysis software and based on the outcomes of a series of in-depth acceleration measurements that were conducted on-site, the model was refined. By using the structural parameters obtained from the dynamic and the static tests, calibrated model of the bridge structure was obtained and this model was used for necessary calculations regarding structural assessment and evaluation.
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... Historically, arch bridges have been mostly known as masonry structures (Figure 2a,b [20,21]) but worldwide examples have been also realized using different materials ( Figure 2c,d [22,23]). the main drawbacks of these types of tests concern the lack of energy to supply the whole experimental layout. ...
... Historically, arch bridges have been mostly known as masonry structures ( Figure 2a,b [20,21]) but worldwide examples have been also realized using different materials (Figure 2c,d [22,23]). [20]; (b) Villanova bridge [21]; (c) Viaduct Cairate [22]; (d) S. Giovanni Paolo II bridge [23]. ...
... Historically, arch bridges have been mostly known as masonry structures ( Figure 2a,b [20,21]) but worldwide examples have been also realized using different materials (Figure 2c,d [22,23]). [20]; (b) Villanova bridge [21]; (c) Viaduct Cairate [22]; (d) S. Giovanni Paolo II bridge [23]. ...
This paper presents the results of an experimental dynamic campaign carried out on a reinforced concrete multi-span arch bridge. Five expeditious ambient vibration tests were conducted separately on five spans (one test in each span) of the bridge using only six piezoelectric uniaxial accelerometers. Modal parameters were identified through the well-known Enhanced Frequency Domain Decomposition (EFDD) procedure developed using Matlab R2021b software. At the same time, a finite element model was accurately implemented through a commercial software (Midas Civil) to evaluate the main modal features. A manual model update was successively pursued varying the elastic modulus of the reinforced concrete to make the identified and numerical modes as close as possible. A complete and suitable instrumentation to perform global experimental dynamic tests is not always available. Recursive/Multiple tests have different advantages: handy, easily executable, and could provide a more robust identification thanks to a statical characterization. The paper aims to highlight the peculiarities of recursive/multiple dynamic tests on multi-span arch bridges. The procedure also provides useful suggestions for designing a permanent and continuous vibration-based monitoring system.
... It should be noted that for these viaduct bridges, material properties were not provided from the original constructional drawings, and any material samples could not be extracted due to the conservation of the architectural heritage. Therefore, the material properties were estimated based on the previous studies on similar structures [73][74][75][76]. ...
... The FE models of the viaduct bridges were validated through comprehensive in-situ field acceleration measurements [76,79,80]. To capture the dynamic response of the viaducts accurately, high-sensitivity accelerometers capable of detecting minimal vibrations were strategically placed at the mid-span points on each side of the bridges. ...
While many railway viaducts still in use in Turkish railway networks are located on active fault zones that produced historical destructive earthquakes, they are not seismically designed in accordance to current standards. This study aims to provide a better understanding about the serviceability fragility of such systems by conducting detailed probability-based seismic assessments under near-field and far-field earthquakes. To achieve this, firstly, 3D finite element models of a range of selected viaducts in Turkey were generated based on their original design drawings. The developed FE models were validated by comparing the analytical modal frequencies with the results of in-situ dynamic tests involving a series of acceleration measurements. Nonlinear time history analyses were then carried out under 25 near-field and 25 far-field real three-component ground motion recordings to obtain the seismic response of each selected viaduct. Subsequently, probabilistic seismic demand models were defined using linear regression analysis to determine relationships between engineering demand parameters (EDPs) and ground motion intensity measures (IMs). Peak ground acceleration (PGA), peak ground velocity (PGV) and spectral acceleration at 1.0 s (Sa (1.0)) were used as the IM parameter, while the maximum lateral displacement of the bridge spans for different service velocities defined in the Eurocode was considered as the EDP at serviceability damage state. Finally, analytical fragility curves for all the selected railway viaducts were developed considering maximum damage probability for the IM levels. The results, in general, demonstrate the seismic vulnerability of the existing viaducts in Turkey. It is shown that while at low speed limits the viaducts exposed to far-field ground motions were more vulnerable than those under near-field ground motions, at high speed limits the viaducts subjected to near-field ground motions were more vulnerable. Also, it is seen that reinforced concrete and masonry viaducts are generally more vulnerable to earthquakes than the steel viaducts. The outcomes of this study should prove useful for the seismic risk assessment, loss estimation and rehabilitation of the railway transportation networks in future studies.
... This fact combined with the resistance offered to this wind component by the facade of each bridge produced sufficient excitation source resulting in small amplitude vibrations that could be recorded by the employed instrumentation. The second type of excitation that was employed, namely vertical in-plane excitation, was produced from a sudden drop of a weight on the deck of each stone masonry bridge (Aoki et al. 2007;Manos et al. 2015aManos et al. ,2015bManos et al. , 2016Manos et al. , 2017Ozden et al 2012;Ruocci et al. 2013). ...
This study presents a method for validation of numerical models of stone masonry arch bridges using in-situ and laboratory measurements. These numerical models are utilized in assessing the expected performance of specific case studies of stone masonry bridge structures in Greece towards meeting the demands of extreme events that include design seismic loads. At first, the work focuses on in-situ measurements conducted at selected old stone masonry bridges, using up-to-date system identification techniques, in an effort to quantify their dynamic characteristics in terms of eigen-frequencies, eigen-modes and damping properties. This information provides a basis for realistic numerical simulations towards studying the structural behaviour of such stone masonry bridges and assessing their expected structural behaviour in extreme future seismic events. Selected in-situ measurements are presented together with their use in numerical models of various levels of complexity. Afterwards, a series of experimental tests are presented on bridge materials (stone blocks and mortar) and triplet shear and bending tests. Through the laboratory measurements non-linear constitutive material or interface laws are determined. Thus, the failure criteria of such structures are employed to 3d solid finite element models used for the seismic assessment of masonry bridge structures.
... Furthermore, through monitoring the bridge stress, they were able to make estimations for the bridge fatigue and maintenance intervals. Caglayan et al. [52] identified a large, historically significant masonry bridge in a seismicity-active region using field experiments. Their model was calibrated using finite element analysis results. ...
Masonry arch bridges are an integral part of the transportation infrastructure, and their vulnerability to seismic events is a significant concern. The factors that contribute to their susceptibility include the age of the bridge, the quality of the materials used in its construction, the bridge geometry, and different vulnerability assessment techniques. This paper aims to provide an in-depth understanding of these factors, their interrelationships, and their impact on the seismic vulnerability of masonry arch bridges. Finally, one of the historical masonry arch bridges in Iran was selected, and the analytical fragility curves were developed to determine the seismic vulnerability. The outcomes of this review hold significant implications for bridge engineers, transportation authorities, and policymakers. However, the review highlights the need for further research to develop more effective mitigation strategies. More research is necessary to understand the complex interplay between the factors contributing to the seismic vulnerability of masonry arch bridges.
... The Schmidt hammer is a low-cost and easy to use tool that using onsite examination of cultural heritage structures [54][55][56]. In this study, an L-type Schmidt hammer was used to determine the surface stiffness of the historical Malatya Taşhoran Church walls (Fig. 21). ...
In this research, computational models of masonry arch bridges were constructed, taking into account distinctive features such as span dimensions, height, and arch thickness, while the arch width was maintained as a constant parameter throughout the modeling process. The finite element analysis software, ANSYS version 16, was utilized to create these computational representations. To evaluate the structural integrity and load-carrying capabilities of these bridges, loading scenarios were applied to both the center section of the bridge and a quarter of the arch span. The analytical methodology adopted for this purpose was static thrust analysis. Subsequently, the study delved into the influence of the geometrical characteristics of the arches on their load-carrying capacity. The findings of this research hold potential utility in guiding and informing the reconstruction of historic bridges that have been completely or partially demolished.
In this study, the topology optimization approach was adopted to reduce the material used in manufacturing. Specifically, the mass optimization technique was deemed suitable. Mass optimization eliminates the parts that don't affect a bracket’s overall strength while under load, resulting in weight reduction and material savings. Two shelf brackets were designed to test this theory and were subjected to mass optimization. A static structural analysis of this optimized model was carried out to confirm the optimization findings. These designs were then manufactured using the 3D-printing process. The yield points were next determined by performing a uniaxial tensile test on the shelf brackets. The outcome of the tests was subsequently compared with the simulation results, and a cost analysis model was created as an output. Ultimately, a reduction of 70% in mass was achieved with acceptable structural strength. In related optimization studies, the connecting part of an unmanned aerial vehicle's landing gear has been optimized resulting in fuel savings. The theory that topology optimization may be used to make both light and stiff parts at the same time has been proven by the results of this research as well as other studies that have been done on the same topic.
The paper summarizes the dynamic-based assessment of a reinforced concrete arch bridge, dating back to the 50's. The outlined approach is based on ambient vibration testing, output-only modal identification and updating of the uncertain structural parameters of a finite element model. The Peak Picking and the Enhanced Frequency Domain Decomposition techniques were used to extract the modal parameters from ambient vibration data and a very good agreement in both identified frequencies and mode shapes has been found between the two techniques. In the theoretical study, vibration modes were determined using a 3D Finite Element model of the bridge and the information obtained from the field tests combined with a classic system identification technique provided a linear elastic updated model, accurately fitting the modal parameters of the bridge in its present condition. Hence, the use of output-only modal identification techniques and updating procedures provided a model that could be used to evaluate the overall safety of the tested bridge under the service loads.
Existing test results of full-scale in-service masonry arch bridges are analysed to determine appropriate material properties for the modelling of this structural type. Three-dimensional nonlinear finite element models of three masonry arch bridges are generated using a commercially available finite element package. The behaviour of the masonry is replicated by use of a solid element that can have its stiffness modified by the development of cracks and crushing. The fill is modelled as a Drucker–Prager material, and the interface between the masonry and the fill is characterised as a frictional contact surface. The bridges are modelled under service loads, and the model results are compared to the results of a program of field testing of the structures. It is found that the assumption of a reasonable set of material properties, based on visual observations of the material and construction of the structure, implemented through a program of three-dimensional nonlinear finite element analysis enable good predictions of the actual behaviour of a masonry arch bridge.
The Tanaro Bridge, an 18 span masonry bridge built in 1866, has been investigated both in service conditions and at different stages of its demolition. A comparative characterization of the brickwork was performed by means of compressive tests on cylinders, flat jacks, sonic and sclerometer tests, while the natural frequencies and mode shapes of the bridge and the brickwork damping have been identified by dynamic tests on the bridge. Data from material testing were used to set up FEM models, so that the reliability of the material characterization procedures is demonstrated by comparison between the dynamic tests and FEM results. A rational comparative analysis of the results showed that: (i) a large part of the bridge needs to be monitored if the mode shapes are to be identified through dynamic tests; (ii) elastic FEM models can provide some information on the bridge response under service loads provided the mechanical parameters are adequately identified. Besides, some information has been deduced on the effectiveness, in service conditions, of some retrofitting technique: (i) transversal tie bars through the arch thickness have been proved almost ineffective; (ii) internal spandrels were found to be quite efficient in connecting adjacent spans.
Recent advances in the analysis of masonry arch bridges, substantiated by extensive testing programs in the United States and Europe, provide bridge engineers and inspectors with increasing confidence that reasonable estimates can be made of the capacity of these structures. Observations of ultimate strength testing indicate that spandrel walls and fill contribute greatly to the strength and stiffness of these structures, and that loads approaching the plastic collapse load can often be obtained. Observations from service load testing indicate that the development of cracking and non-linearity under service loads can be a significant indicator of the capacity of the structure. Modeling of these structures has shown the importance of restraint of the abutment to the overall resistance of the structure, and has recently shown the importance of transverse effects in diminishing the strength of structures with high spandrel walls or thin arch rings.
An efficient numerical procedure based on the cubic spline technique is developed to obtain the vertical displacements of the bridge deck using the slope values measured at selected points under the test loading. Most static load tests of bridges are performed to evaluate the stiffness characteristics of bridge structures or to check the accuracy of their computer models. From this standpoint, vertical displacements of the bridge under certain loads have a crucial importance. However, if the bridge is over a river, a lake, muddy ground, or a major highway, conventional displacement transducers cannot be used appropriately for this purpose. Furthermore, strong wind and the bridge's height badly affect the accuracy of the transducers. Another way to obtain bridge deflections is to use an indirect method. Tiltmeters, which have been increasingly used for construction monitoring and structural testing of bridges, are suitable devices in terms of indirect deflection measurements because of their characteristics such as high sensitivity, easy installation, and small electrical drift. The testing and evaluation procedure developed was applied on a real bridge, and the results indicated that this method could be applied to obtain vertical displacements of bridges as an alternative to the use of conventional displacement transducers.
The behavior of filled masonry arch bridges under truck loading is examined by service load testing and by developing a finite-element model of a unit width of the structure. The held tests included five structures varying in span from 3 to 12 m. The structures tested included a group of three structures of similar geometry, material, age, and geographic location. The testing program demonstrated the significance of the linearity of the response to different loading levels and the importance of permanent deformations in evaluating a structure. The field tests also gave evidence of the range of responses of similar structures, and showed some evidence of the development of an incipient mechanism. The analytical model included approximation of the load distribution through the fill and the restraint to movements of the arch ring developed by the fill and spandrel walls. Reasonable approximations of the experimentally observed response of the structures were obtained using the analytical model. Guidance in selecting material properties and stiffnesses for the abutments and fill-in modeling masonry arch structures is given.
To evaluate the remaining strength of a plain concrete arch bridge, dynamic and static load test was carried out. In the static test, up to 7300 kN of weight was applied, and in the dynamic test, a 1200 kN locomotive was used. The bridge demonstrated relatively stiff and strong response, despite initiation of enormous cracks, and it yielded under load levels much greater than the service load. The performance could be compared to a multi-layered continuous structure rather than to an arch form. The study showed that the bridge still enjoyed relatively large strength reserve and proper dynamic performance, despite deep and wide cracks, suffering from carbonation, and being more than 60-year old.
The assessment of unreinforced masonry structures, especially in arched or vaulted forms, is difficult to undertake in practice. A structural engineer is often confronted with a standing, apparently competent, structure that seems to defy most of the rules of structural behavior as incorporated in modern building codes. The engineer must then choose between reinforcing the structure according to a modern understanding of material strength and structural behavior or trying to make sense of the behavior and anticipated strength of the structure on a more fundamental level. A manual has been developed to introduce a sympathetic structural engineer to some of the principles of unreinforced masonry and to provide some basic instructions in preparing a finite element model of complex vaulted masonry structures using widely available modern tools of structural analysis (Boothby et al. 2006). Based on the manual, this paper gives guidance on the application of finite element tools for linear and non-linear assessment of arches. Detailed instructions are given for development of geometric models, solid models and meshing and entering material properties, boundary conditions and loads for models of complex three-dimensional structures, such as domes and vaults.
This paper describes the static, dynamic and long-term tests of bridges in situ, which have been performed in the Czech and Slovak Republics since 1968. The standard methods are supplemented with the criteria for the elastic and permanent deformations, natural frequencies and the dynamic impact factors. The monitoring of stresses under usual traffic loads provides important data for the fatigue of bridges, for the estimation of their residual life and for the determination of inspection intervals. Modal analysis and identification ascertain the characteristic properties of bridges from their response. The damage in bridges may be reflected in the changes of their natural frequencies or modes of natural vibration.
Measurements are increasingly used to augment traditional assessments of structural state. Measurements of deflections, rotations and strain provide indications of damages as well as changes in the values of parameters such as Young's modulus. Finite element model updating methods have been developed in the 1990s for identifying structural state from measurements. Currently most methods aim to determine the values of stiffness coefficients that result in measured responses. In the present work, a model calibration method identifies causes of structural behaviour such as support conditions and material properties. Static measurement data is employed for model calibration. A case study of the Lutrive bridge in Switzerland illustrates the methodology. Candidate models whose responses reasonably match measured data are identified. These models are then examined in order to determine whether the calibrated values are physically possible. Such examinations lead to either model rejection or further measurements.