Project

RAMBEA - Realistic Assessment of Historical Masonry Bridges under Extreme Environmental Actions

Goal: The RAMBEA project aims at developing a novel computational strategy for accurate and efficient simulations of historical masonry bridges subject to extreme environmental actions, including loadings induced by earthquakes and flooding. The aim is to provide a comprehensive tool for realistic assessment with the potential of transforming current practice related to strengthening of critical assets, contributing to an increased resilience of the built environment and the preservation of important elements of the architectural heritage, thus responding to the safety and socio-economic needs. Old masonry bridges still play a critical role within the European transportation system. Moreover, they belong to the architectural heritage representing a valuable expression of past construction technology. Many of these structures are located in seismic regions and in areas subject to floods and hydrogeological instability which have been aggravated by climate change. Thus they can be exposed to extreme environmental actions which may potentially lead to bridge failure causing significant economic damage and the loss of structures with cultural and historical value. Currently, the response of masonry bridges under extreme loading is evaluated using simplified models due to the lack of efficient detailed models. However, these approaches do not allow for the complex 3D behaviour potentially leading to unrealistic and unsafe predictions. The main challenge of this project is the development of a more advanced strategy, based on a novel numerical description allowing for the 3D interaction between the different bridge components under extreme loading. More specifically, within the project it will be developed an efficient 3D finite element representation with macro-elements for the masonry parts of the bridge, an accurate description for the physical interface between masonry and backfill and an effective model calibration strategy utilising the results of non-destructive tests.

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Project log

Bartolomeo Pantò
added a research item
This paper presents the results of a numerical study on the Quebradas viaduct, which is located in the Minho region, a low-to-medium seismic risk area in Northern Portugal. The 5-span viaduct, which is made of regular granitic blocks, was built at the beginning of the 20th century. The bridge structure has been analysed by nonlinear dynamic analysis to represent the response up to collapse under earthquake loading. Numerical simulations have been performed adopting a macromodelling approach with a recently developed macroscale anisotropic masonry model with embedded discontinuities [1]. The model allows for the actual masonry bond requiring simple material calibration and enables the representation of tensile cracking, crushing and shear damage in the brick/blockwork. A two-scale representation is utilised, where 3D continuum elements at the structural scale are linked to embedded nonlinear interfaces representing mortar joints at the mesoscale. The adopted masonry material model has been validated against physical experiments in previous research within the RAMBEA project [2], considering the response of masonry arch and bridge specimens under cyclic loading, including dynamic actions induced by earthquakes [3].
Bartolomeo Pantò
added 2 research items
The paper presents a novel effective macro-modelling approach for masonry arches and bridges under cyclic loading, including dynamic actions induced by earthquakes. It utilises an anisotropic material model with embedded discontinuities to represent masonry nonlinearities. Realistic numerical simulations of masonry arch bridges under static and dynamic loading require accurate models representing the anisotropic nature of masonry and material nonlinearity due to opening and closure of tensile cracks and shear sliding along mortar joints. The proposed 3D modelling approach allows for masonry bond via simple calibration, and enables the representation of tensile cracking, crushing and shear damage in the brickwork. A two-scale representation is adopted, where 3D continuum elements at the structural scale are linked to embedded nonlinear interfaces representing the meso-structure of the material. The potential and accuracy of the proposed approach are shown in numerical examples and comparisons against physical experiments on masonry arches and bridges under cyclic static and dynamic loading.
Bartolomeo Pantò
added a research item
This paper presents an efficient hybrid continuum-discrete macro-modelling strategy with an enhanced multiscale calibration procedure for realistic simulations of brick/block-masonry bridges. The response of these structures is affected by the intrinsic nonlinearity of the masonry material, which in turn depends upon the mechanical properties of units and mortar joints and the bond characteristics. Finite element approaches based upon homogenised representations are widely employed to assess the nonlinear behaviour up to collapse, as they are generally associated with a limited computational demand. However, such models require an accurate calibration of model material parameters to properly allow for masonry bond. According to the proposed approach, the macroscale material parameters are determined by an advanced multi-objective strategy with genetic algorithms from the results of mesoscale “virtual” tests through the minimisation of appropriate functionals of the scale transition error. The developed continuum-discrete finite element macroscale description and the calibration procedure are applied to simulate the nonlinear behaviour up to collapse of multi-ring arch-bridge specimens focusing on the 2D planar response. The results obtained are compared to those achieved using detailed mesoscale models confirming the effectiveness and accuracy of the proposed approach for realistic nonlinear simulations of masonry arch bridges.
Bartolomeo Pantò
added an update
This session aims to present the most recent developments in the modelling, analysis and assessment of masonry vaulted structures and arch bridges. The focus is on computational methods and applications, thus particular attentions will be given to new mechanical descriptions, novel numerical techniques for nonlinear analysis but also to new experimental work for model validation and computer-based approaches for practical safety assessments.
There will also be the opportunity for authors of accepted abstracts who present their papers at the conference to submit their full paper for review and possible publication in the conference special issues of Computers & Structures (CAS) or Advances in Engineering Software. Further information can be found at the website: http://www.cstconference.com/
Deadline for submission of short papers 18th March 2022.
 
Bartolomeo Pantò
added a research item
A great proportion of the existing architectural heritage, including historical and monumental constructions, is made of brick/block masonry. This material shows a strong anisotropic behaviour resulting from the specific arrangement of units and mortar joints, which renders the accurate simulation of the masonry response a complex task. In general, mesoscale modelling approaches provide realistic predictions due to the explicit representation of the masonry bond characteristics. However, these detailed models are very computationally demanding and mostly unsuitable for practical assessment of large structures. Macroscale models are more efficient, but they require complex calibration procedures to evaluate model material parameters. This paper presents an advanced continuum macroscale model based on a two-scale nonlinear description for masonry material which requires only simple calibration at structural scale. A continuum strain field is considered at the macroscale level, while a 3D distribution of embedded internal layers allows for the anisotropic mesoscale features at the local level. A damage-plasticity constitutive model is employed to mechanically characterise each internal layer using different material properties along the two main directions on the plane of the masonry panel and along its thickness. The accuracy of the proposed macroscale model is assessed considering the response of structural walls previously tested under in-plane and out-of-plane loading and modelled using the more refined mesoscale strategy. The results achieved confirm the significant potential and the ability of the proposed macroscale description for brick/block masonry to provide accurate and efficient response predictions under different monotonic and cyclic loading conditions.
Bartolomeo Pantò
added a research item
A great proportion of the existing architectural heritage, including historical and monumental constructions, is made of brick/block masonry. This material shows a strong anisotropic behaviour resulting from the specific arrangement of units and mortar joints, which renders the accurate simulation of the masonry response a complex task. In general, mesoscale modelling approaches provide realistic predictions due to the explicit representation of the masonry bond characteristics. However, these detailed models are very computationally demanding and mostly unsuitable for practical assessment of large structures. Macroscale models are more efficient, but they require complex calibration procedures to evaluate model material parameters. This paper presents an advanced continuum macroscale model based on a two-scale nonlinear description for masonry material which requires only simple calibration at structural scale. A continuum strain field is considered at the macroscale level, while a 3D distribution of embedded internal layers allows for the anisotropic mesoscale features at the local level. A damage-plasticity constitutive model is employed to mechanically characterise each internal layer using different material properties along the two main directions on the plane of the masonry panel and along its thickness. The accuracy of the proposed macroscale model is assessed considering the response of structural walls previously tested under in-plane and out-of-plane loading and modelled using the more refined mesoscale strategy. The results achieved confirm the significant potential and the ability of the proposed macroscale description for brick/block masonry to provide accurate and efficient response predictions under different monotonic and cyclic loading conditions.
Bartolomeo Pantò
added an update
Within the RAMBEA project, an in-situ experimental programme, including non-destructive tests, has been carried out on the Quebradas Viaduct, Baião, Portugal, in collaboration with the Historical and Masonry Structures research group of the University of Minho. The experimental campaign comprised ambient vibration tests aimed at identifying natural frequencies and vibration modes of the bridge, sonic tests, and GPR tests to evaluate the thicknesses of external masonry leaves and masonry elastic properties. The results of the campaign will support the development of detailed mesoscale and macroscale models implemented by the Computational Structural Mechanics Group of Imperial College London to assess the performance of the viaduct under different loading scenarios, including traffic and earthquakes.
 
Bartolomeo Pantò
added a research item
Masonry vaults are present in a large number of historical structures and often used as flooring and roofing systems in monumental palaces and religious buildings, typically incorporating no backfill. Many of these structures are located in seismic regions and have been shown to be particularly vulnerable during recent earthquakes, with a need for accurate modelling to avoid future losses. Masonry vaults are often analysed using limit analysis procedures under the hypotheses of no-tension material and absence of sliding along the masonry joints. However, this method can be inaccurate for barrel vaults found in buildings, which are typically slender with no backfill. In this case, the masonry tensile strength and the progressive damage propagation play an important role in the nonlinear behaviour and ultimate strength of the vault. In this study, a detailed mesoscale finite element mesoscale approach is used to model slender unreinforced barrel vaults subjected to cyclic quasi-static and dynamic loading. According to this approach, 3D solid elements connected by 2D damage-plasticity interfaces are used to represent the arrangement of bricks and mortar present in the masonry. The proposed numerical description is first validated against the results from physical tests on a barrel vault under quasi-static cyclic loading. Subsequently, the shear response of a prototype vault is analysed by performing nonlinear simulations under prescribed horizontal displacements at the supports, considering also the influence of previous damage induced by earthquakes with different magnitudes.
Bartolomeo Pantò
added a research item
Masonry arches represent the most important structural components of masonry arch bridges. Their response is strongly affected by material nonlinearity which is associated with the masonry texture. For this reason, the use of mesoscale models, where units and mortar joints are individually represented, enables accurate response predictions under different loading conditions. However, these detailed models can be very computationally demanding and unsuitable for practical assessments of large structures. In this regard, the use of macro-models, based on simplified homogenised continuum representations for masonry, can be preferable as it leads to a drastic reduction of the computational burden. On the other hand, the latter modelling approach requires accurate calibration of the model parameters to correctly allow for masonry bond. In the present paper, a simplified macro-modelling strategy, particularly suitable for nonlinear analysis of multi-ring brick-masonry arches, is proposed and validated. A numerical calibration procedure, based on genetic algorithms, is used to evaluate the macro-model parameters from the results of meso-scale "virtual" tests. The proposed macroscale description and the calibration procedure are applied to simulate the nonlinear behaviour up to collapse of two multi-ring arches previously tested in laboratory and then to predict the response of masonry arches interacting with backfill material. The numerical results confirm the ability of the proposed modelling strategy for masonry arches to predict the actual nonlinear response and complex failure mechanisms, also induced by ring separation, with a reduced computational cost compared to detailed mesoscale models.
Bartolomeo Pantò
added a project goal
The RAMBEA project aims at developing a novel computational strategy for accurate and efficient simulations of historical masonry bridges subject to extreme environmental actions, including loadings induced by earthquakes and flooding. The aim is to provide a comprehensive tool for realistic assessment with the potential of transforming current practice related to strengthening of critical assets, contributing to an increased resilience of the built environment and the preservation of important elements of the architectural heritage, thus responding to the safety and socio-economic needs. Old masonry bridges still play a critical role within the European transportation system. Moreover, they belong to the architectural heritage representing a valuable expression of past construction technology. Many of these structures are located in seismic regions and in areas subject to floods and hydrogeological instability which have been aggravated by climate change. Thus they can be exposed to extreme environmental actions which may potentially lead to bridge failure causing significant economic damage and the loss of structures with cultural and historical value. Currently, the response of masonry bridges under extreme loading is evaluated using simplified models due to the lack of efficient detailed models. However, these approaches do not allow for the complex 3D behaviour potentially leading to unrealistic and unsafe predictions. The main challenge of this project is the development of a more advanced strategy, based on a novel numerical description allowing for the 3D interaction between the different bridge components under extreme loading. More specifically, within the project it will be developed an efficient 3D finite element representation with macro-elements for the masonry parts of the bridge, an accurate description for the physical interface between masonry and backfill and an effective model calibration strategy utilising the results of non-destructive tests.