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The Structural Performance of Stone-Masonry Bridges
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... On the contrary, their size spans from 8m to 40m when a single arch is employed (Konitsa) or over 70m for multi-arch structures (Plaka). More information on the geometry, construction characteristics and mechanical properties of the employed materials are given by Manos et al. (2016). Today, these structures have retain but only a small part of this primary function, as new roads and bridges have been built to facilitate the contemporary transportation needs. ...
... Due to space limitations only selective measurements of the out-of-plane response, which was recorded utilizing either the wind or the drop weight excitation are included here. More information is reported by Manos et al. (2016). Frequency range (Hz) F F T amplitud e (mm/sec) Out-of-plane Hor. ...
... All available information, measured during the in-situ campaign, on the geometry of each one of these parts was used in building up these numerical simulations. The mechanical property values obtained from the stone and mortar sample tests were utilized (see Manos et al. (2016). Moreover, there is important information that is needed in order to form with some real-ism the boundary conditions at the river bed and banks. ...
... 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.
... Maintenance tasks such as inspections, repairs, and upgrades are vital for preserving structural integrity and performance [22]. Research has shown that maintenance levels significantly influence infrastructure vulnerability to seismic events, highlighting a gap in how maintenance practices influence seismic risks [23], [24], [25], [26], [27], [28], [29]. Infrastructure functionality critically depends on each component's consistent performance, making maintenance crucial for mitigating seismic vulnerability. ...
A severe seismic event can cause significant damage to infrastructure systems, leading to both direct and indirect severe consequences. Thus, a comprehensive risk management approach is essential for developing earthquake-resilient infrastructure. This study introduces an innovative approach to seismic risk assessment that incorporates maintenance considerations with seismic fragility curves. Our methodology distinctively quantifies the impact of maintenance conditions on seismic risk, providing insights into the dynamic evolution of risk associated with loose maintenance and accelerated deterioration. It suggests that the condition of infrastructure maintenance and its level of deterioration significantly influence seismic resilience. By integrating the Building Performance Indicator (BPI) with deterioration over time, the proposed approach assesses their combined effect on fragility curves to calculate the total risk over the infrastructure's lifecycle (TRLC – Total Risk over Life Cycle). We demonstrate this methodology through a case study of a low-voltage substation in Bik'at HaYarden, Israel. A Monte Carlo simulation was carried out to examine the particular conditions of the substation thoroughly. Additionally, a sensitivity analysis was carried out to better understand how maintenance conditions influence the TRLC over time. Our findings reveal a statistically significant correlation between infrastructure performance and maintenance condition, and their subsequent impact on the TRLC. Notably, we found that loose maintenance conditions significantly increase the uncertainties in seismic risk. This research offers researchers, stakeholders, and decision-makers a novel and comprehensive view on the critical role of maintenance in managing and mitigating seismic risk.
... Several studies aimed to consider maintenance parameters regarding seismic vulnerability. Manos et al. [35] discussed maintenance issues related to the structural integrity of stone-masonry bridges. However, no analytical process was introduced. ...
A severe seismic event can cause significant damage to infrastructure systems, resulting in severe direct and indirect consequences. A comprehensive risk-management approach is required for earthquake-resilient infrastructure. This study presents an innovative approach to seismic risk assessment and aims to integrate maintenance considerations with seismic fragility curves. The proposed methodology uniquely quantifies the impact of maintenance conditions on seismic risk, presenting a dynamic perspective of risk changes attributable to maintenance and deterioration. The methodology hinges on the hypothesis that the maintenance condition of the infrastructure and the level of deterioration impacts the seismic resilience of the infrastructure. The methodology synergizes the Building Performance Index (BPI) and the deterioration over time to evaluate their cumulative effect on fragility curves to estimate the infrastructure’s total risk over the lifecycle (TRLC). This proposed methodology is demonstrated through a case study of a low-voltage substation in Bik’at HaYarden, Israel. A Monte Carlo simulation was carried out for the specific conditions of the analyzed substation. A comprehensive sensitivity analysis was performed to understand better the effect of maintenance conditions over time on the TRLC. Key insights reveal a statistically significant correlation between infrastructure performance and maintenance and their consequential impact on the TRLC. Notably, declining maintenance conditions intensify seismic risk uncertainties. The research proposes to researchers, stakeholders, and decision-makers a novel comprehensive perspective on the indispensability of maintenance for seismic risk management and mitigation.
... As in all such cases, the most challenging stage of this work was developing the input parameters due to the lack of reliable information about the mechanical properties of the stones that make up the bridge. To mitigate this, articles about similar bridges in nearby cities in Turkey and other countries were studied [8,[14][15][16][17], and geotechnical studies in the Kurdistan Region were taken into account. In particular, the work of Daoud et al. [18] was consulted, where the authors presented valuable data on the mechanical properties of limestone in our region. ...
This study aimed to investigate the stress-strain and strain energy density (SED) states of Dalal stone arch bridge in Mesopotamia. Structural modeling of ancient bridge made of natural stone has been proven reliable, and accurate results have been obtained using 3D finite elements. Based on the more applicable theories of failure, a general methodology is presented for evaluating the ringstone of the largest ellipse-shaped arch of the Dalal Bridge. The elliptical arch was built in the COMSOL Multiphysics complex using 70 3D elements to represent the number of stones used along the length of the arch in the Dalal Bridge. Therefore, to create an accurate model, the coordinates of the four nodes of each stone were entered. Then, all domains were extruded for 0.8 m in the y-axis direction, i.e., 0.8 m of the bridge width was selected for investigation. That is, tapered fields were used to represent the stones of the arch ring. Using Rankine’s, St. Venant’s, and Haigh’s theories, the qualitative and quantitative characteristics of all components of the stresses and SED states are investigated. The maximum positive values of the principal stresses, σ1, σ2, and σ3, in the 3D model reach 1.4, 0.51, and 0.09 MPa, respectively, and their maximum negative values were 13, 6.8, and 3.4 MPa, respectively. The equivalent principal stresses determined via a 2D investigation did not exceed these values. Evaluating the ringstone against the maximum principal strain theory (i.e., St. Venant’s theory) reveals a safety factor of four in the existing state. Also, application of Haigh’s theory confirms the results of the previously applied approaches. Even though the safety of the arch, according to the total strain energy theory (i.e., Haigh’s approach), has been verified, a significant variation in the nonuniformity of the distribution of the SED (0.0011 J/m3–4416 J/m3) confirmed that the geometry of the investigated arch is not optimal for applied loading. The maximum value of the vertical component of the displacement is 3.4 mm, significantly lower than the allowable deflection for such an arch span.
... Bricks and mortar are well-known to behave and interact nonlinearly and accordingly to complex models (for instance, Ref. [4] analysed in detail the evolutionary phenomenon of mortar de-bonding, while Ref. [54] proposed an identification procedure for seismic damage); splitting or surface spalling may happen due to stress concentration over time, and loss of bricks cohesion, while generally unlikely, is not impossible. The interested audience may refer to Ref. [5] for a deeper discussion about the structural performances of masonry bridges in the context of Structural Bridge Engineering. ...
The increasingly request for the maintenance of the architectural heritage has led in the last decades to the extensive use of System Identification (SI) techniques for Structural Health Monitoring (SHM) purposes. These proved to be useful tools for assessing the state of conservation of the built environment and its behaviour in operating conditions. In particular, historical masonry structures and infrastructures present several compelling difficulties. Masonry is non-linear and its mechanical properties are uncertain due to the presence of local irregularities and its internal texture. Moreover, centuries-old buildings are severely affected by deterioration, eventual restoration interventions, and exposure to weather conditions. In this work, the Fast Relaxed Vector Fitting (FRVF) approach is proposed as a rapid, efficient, and reliable instrument for the vibration-based SI of such structures. The method is preliminarily validated on simple numerical examples and a multi-damaged cantilevered box beam, then tested on a true 1:2 scaled model of a masonry two-span arch bridge. The results match well the estimations from other well-established SI techniques, such as the Eigensystem Realization Algorithm (ERA), and can be utilised for damage assessment (with all the standard advantages and limitations of modal-based outlier detection). Stabilisation diagrams and frequency-damping plots are also proposed for FRVF.
The present study presents a series of in-situ measurements conducted at selected old stone masonry bridges, using up-to-date system identification techniques, in an effort to identify their dynamic characteristics in terms of eigen-frequencies, eigen-modes and damping properties. All these information is part of a data base that can be used in the future as a reference for identifying noticeable changes in these dynamic characteristics as part of a structural health monitoring effort for these bridges. Moreover, this information provides a basis for build-ing 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 building numerical models of various levels of complexity. These numerical models are finally utilized in assessing the expected performance of specific case studies of stone masonry bridge structures in Greecetowards meeting the demands of extreme events that include design earth-quake loads. The described system identification technique can also be linked to specific actions, such as earthquake activity, and thus serve as warning for specific maintenance counter-measure.
The seismic performance of “Greek” churches made by low-strength unreinforced masonry is examined. These structures were damaged during recent strong seismic activity in Greece combined with long term effects from foundation settlement. Measurements from shear-sliding laboratory tests of stone masonry triplets are presented and discussed together with corresponding numerical simulation results in an effort to quantify the in-plane sliding shear failure criterion. The cohesive surface interaction constitutive law was employed in forming realistic limit-state criteria for such weak mortar stone masonry. Next, the performance of specific “Greek” churches is numerically simulated employing simplified dynamic linear elastic analysis and assumed limit-state criteria. This simplified approach yielded realistic predictions of the observed performance. However, the necessity to obtain a comprehensive set of measured strength properties for such type of masonry construction is underlined. From this simplified dynamic linear elastic analysis it can be concluded that the soil-foundation deformability results in a significant increase in the tensile stress demands at critical regions. This conclusion is also in agreement with the observed damage.
Mexico has an important number of cities recognized by the UNESCO as World Heritage Site. Many of them have highway and railway bridges with an important historical value product of the construction techniques and materials implemented in those days. In spite of their importance, very few efforts have been led to study the masonry historic bridges’ origin and pathologies that eventually would conduct to a failure condition. The main objectives of this work are to identify the dynamic properties of the masonry historic bridges, to characterize, in a second stage, bridges pathologies, to develop numerical models that allow the correct identification of the structural components of the bridges and subsequently to identify the damage mechanisms of this type of structures, and finally to evaluate the influence of the epicentral distance and seismic fault on the seismic vulnerability of the bridges. The study determines the dynamic properties of five existing historical bridges by conducting a campaign of ambient vibration tests. These results allowed to calibrate numerical models used to construct fragility curves and to determine the seismic vulnerability of the bridges.
The study presents the results of an investigation that identifies among the available records in Greece those that reveal near-source characteristics, using a procedure based on damage potential parameters. The findings reaffirm the opinion that earthquakes with magnitude less than M ¼ 6.0 present near-source phenomena that can cause severe damage to relatively stiff structures, common in urban areas. Spectra from selected accelerograms of near-source records are compared with the corresponding elastic spectra of the current Greek Seismic Code, (EAK 2000), the impulsive character of the Greek near-source records is ascertained and shortcomings of EAK 2000 to account for near-source effects are demonstrated. Based on records from seismic events in Greece and records from international earthquakes of small-to-moderate magnitude, the study demonstrates that there exists a near-source magnitude-distance region, where the velocity pulses have smaller amplitude and period in comparison with earthquakes of great magnitude. A simplified representation of three pulse types is, also, adopted for near-source events. It is found that the type-A pulse related to permanent displacement phenomena does not characterize Greek records. In addition a simple criterion is developed to identify the most appropriate simplified pulse type for near-source seismic events independently of magnitude. r
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.
The subject of earthquake engineering has been the focus of my teaching and research for many years. Thus, when Mario Paz, the editor of this handbook, asked me to write a Foreword, I was interested and honored by his request. Worldwide, people are beginning to understand the severity of the danger to present and future generations caused by the destruction of the environment. Earthquakes pose a similar threat; thus, the proper use of methods for earthquake-resistant design and construction is vitally important for countries that are at high risk of being subjected to strong-motion earthquakes. Most seismic activity is the result of tectonic earthquakes. Tectonic earthquakes are very special events in that, although they occur frequently, their probability of becoming natural hazards for a specific urban area is very small. When a severe earthquake does occur near an urban area, however, its consequences are very large in terms of structural destruction and human suffering.
Past earthquake disasters in Greece, during the last thirty years, demonstrate that the severity of destruction is not only due to the intensity of the seismic event but also to the urbanization of the affected region and the vulnerability of certain types of buildings. Considerable damage was sustained by both old unreinforced masonry structures as well as by relatively new multistory reinforced concrete structures with "soft story" at their ground floor level. The most important observations made during six past earthquake disasters are presented in a summary form and discussed. The most remarkable case of extensive structural damage was caused from the resent Athens 1999 earthquake. The consequent discussion focuses on the following issues: (1) Classification of structural damage and their underlying causes. (2) Repair and strengthening of damaged structures. (3) Upgrade the seismic design. (4) Plans for earthquake preparedness. (5) Assessing the vulnerability of certain type of structures (schools, hospitals, public buildings etc). (6) Education specialized in earthquake engineering. (7) The enrichment of the strong motion data base.
The focus of this paper is to illustrate the importance of model calibration and in situ vibration testing by comparing the finite element model predictions of the earthquake response of the two historical arch bridges, Osmanlı and Şenyuva, before and after model calibration. The three-dimensional finite element models of these two arch bridges, built in the ANSYS finite element program, are used to predict bridge dynamic characteristics, such as natural frequencies and mode shapes. Following the analytical study, ambient vibration tests were conducted to experimentally obtain dynamic characteristics of these two bridges. During ambient vibration tests, accelerometers were placed at several points on the bridge to collect the vibration response due to natural and operational excitation sources. Enhanced frequency domain decomposition and stochastic subspace identification techniques were used to extract the experimental natural frequencies, mode shapes and damping ratios. Finite element models of the two arch bridges were adjusted such that the model predictions reproduce the ambient vibration test results with increased fidelity. The behavior of the masonry arch bridges under earthquake excitation recorded during the Erzincan Earthquake in 1992 is simulated by both the initial and adjusted finite element models. The findings of this study emphasize the importance of model calibration and ambient vibration testing.
In this paper is studied the ultimate failure (limit) load of stone arch bridges. The proposed model is based on finite element analysis with interfaces, simulating potential cracks, which allow for unilateral contact with friction. Opening or sliding of some interface indicates crack initiation. The ultimate load has been calculated by using a path-following (load incrementation) technique. Lack of a solution at a certain level of loading indicates onset of failure. For the validation of the proposed method, which is based on the contact model, the ultimate failure load is recalculated by using a modern implementation of the classical collapse mechanism method based on linear programming. Finally, the beneficial effect of the fill on the limit load of a real bridge is estimated and compared with experimental results.