This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destruct...This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destructive and non-destructive tests. Two different methods are used to evaluate the bridge seismic vulnerability. The first method adopts a deterministic approach and corresponds to a single non-linear static analysis, performed as described in the Eurocodes. The second method employs a probabilistic approach and considers the variability of the involved mechanical parameters(structure geometry and properties of the building materials) and seismic parameters(intensity of the action and site conditions). This method associates the probabilistic values of ground acceleration exceedance to the estimated seismic vulnerability. This is shown by means of fragility curves, which allow to take into consideration the uncertainty of the various components involved in the definition of the seismic vulnerability and display the seismic damage scenarios. Currently no code requires to perform this calculation procedure. In addition,this work compares the values of masonry mechanical properties specified in the Eurocodes with those obtained in an extensive investigation campaign involving more than one hundred masonry bridges. Compressive strength and longitudinal elasticity modulus are the relevant mechanical parameters investigated. The outcomes of this research can contribute to the development of a more efficient maintenance system of the masonry bridges belonging to the railway network. This has an important role when it comes to establishing the priority order of assets intervention.展开更多
This paper demonstrates that Venetian architecture was the result of specifically conceived structural mechanics and construction techniques,which allowed structural design to take full advantage of materials.Venice w...This paper demonstrates that Venetian architecture was the result of specifically conceived structural mechanics and construction techniques,which allowed structural design to take full advantage of materials.Venice witnessed the creation of “structural art” that drastically reduced the incidences of failure caused by extremely soft soils and aggressive environment,which extended the operating horizons of masonry and timber structural materials to the extent that very bold structures were obtained also before the preeminent materials of modern structures.While normal masonry constructions can be governed by Euclidean geometry,Venetian buildings are far more complex and elusive in form.Venice and its architecture can be interpreted and comprehended only in the remit of structural engineering,which played a central role in enabling the construction of the city.The fundamental determinants of Venetian building morphology—the underlying logic of form in architecture,entailed a tectonic form midway between the masonry construction and the skeletal structure.展开更多
In this paper,numerical non-linear analyses of the “Guglie” bridge,located in the historical city of Venice(Italy),are proposed.The focus is twofold:on the sensitivity of the realized shape of the bridge by referenc...In this paper,numerical non-linear analyses of the “Guglie” bridge,located in the historical city of Venice(Italy),are proposed.The focus is twofold:on the sensitivity of the realized shape of the bridge by reference to originally designed shape;and on sensitivity to mechanical parameters of constituent materials.The history of this bridge is very interesting,and the bridge actually built is different from the Marchesini’s project(1580).In fact,in the original design drawing,the shape of the arch is a perfect circle arch,while the shape of the actually built arch is not perfectly circular.Hence,in the aim to evaluate sensitivity of bridge behaviour to designed and realized shape,non-linear analyses are carried on by means of FEMs(Finite Element Models)under in-plane state hypothesis.Furthermore,parametric tests are also performed for evaluating the influence of masonry mechanical parameters on non-linear bridge behaviour.展开更多
Kathmandu World heritage buildings are made from low strength construction especially traditional bricks. From the lesson from 2015 Gorkha earthquake, saving those buildings in severe quake has been a challenging job....Kathmandu World heritage buildings are made from low strength construction especially traditional bricks. From the lesson from 2015 Gorkha earthquake, saving those buildings in severe quake has been a challenging job. It requires proper assessment of its mechanical properties and strengthening as per seismic requirement. An investigation of mechanical properties on brick masonry heritage building has been done and presented here. Nondestructive test - elastic wave tomography at existing walls of the buildings and destructive tests shear, compression and combined loadings on the wallets made from bricks collected from old buildings The several test tests were conducted to find the properties of brick elements and walls such as, density, modulus of elasticity, Poisson’s ratio, shear modulus, shear wave velocity.展开更多
On 26 th October 2015, an Mw 7.5 earthquake struck northern Pakistan, with its epicenter located 45 km southwest of Jarm in the Hindu Kush region of Afghanistan. The earthquake resulted from reverse faulting at a dept...On 26 th October 2015, an Mw 7.5 earthquake struck northern Pakistan, with its epicenter located 45 km southwest of Jarm in the Hindu Kush region of Afghanistan. The earthquake resulted from reverse faulting at a depth of 210 km, resulting in 280 fatalities and substantial damage to some 109,123 buildings. Regional seismicity, characteristics of recorded strong motions, damage statistics, and building performance observations are presented. Earthquake damage was mostly constrained to seismic-deficient unreinforced masonry(URM) buildings. Typical failure modes included toppled minarets, partial or complete out of plane collapse of URM walls, diagonal shear cracking in piers, flexural cracking in spandrels, corner damage, pounding damage, and damage due to ground settlement. The majority of human loss resulted due to failure of URM walls and subsequent roof collapse. URM buildings located in rural hilly areas closer to the epicenter suffered more intense and frequent damage than urban URM buildings located farther away in larger cities.展开更多
基金a collaboration between Sapienza University of Rome and Standard Infrastructure Civil and ExperimentalItalian Railway Network(RFI).
文摘This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destructive and non-destructive tests. Two different methods are used to evaluate the bridge seismic vulnerability. The first method adopts a deterministic approach and corresponds to a single non-linear static analysis, performed as described in the Eurocodes. The second method employs a probabilistic approach and considers the variability of the involved mechanical parameters(structure geometry and properties of the building materials) and seismic parameters(intensity of the action and site conditions). This method associates the probabilistic values of ground acceleration exceedance to the estimated seismic vulnerability. This is shown by means of fragility curves, which allow to take into consideration the uncertainty of the various components involved in the definition of the seismic vulnerability and display the seismic damage scenarios. Currently no code requires to perform this calculation procedure. In addition,this work compares the values of masonry mechanical properties specified in the Eurocodes with those obtained in an extensive investigation campaign involving more than one hundred masonry bridges. Compressive strength and longitudinal elasticity modulus are the relevant mechanical parameters investigated. The outcomes of this research can contribute to the development of a more efficient maintenance system of the masonry bridges belonging to the railway network. This has an important role when it comes to establishing the priority order of assets intervention.
文摘This paper demonstrates that Venetian architecture was the result of specifically conceived structural mechanics and construction techniques,which allowed structural design to take full advantage of materials.Venice witnessed the creation of “structural art” that drastically reduced the incidences of failure caused by extremely soft soils and aggressive environment,which extended the operating horizons of masonry and timber structural materials to the extent that very bold structures were obtained also before the preeminent materials of modern structures.While normal masonry constructions can be governed by Euclidean geometry,Venetian buildings are far more complex and elusive in form.Venice and its architecture can be interpreted and comprehended only in the remit of structural engineering,which played a central role in enabling the construction of the city.The fundamental determinants of Venetian building morphology—the underlying logic of form in architecture,entailed a tectonic form midway between the masonry construction and the skeletal structure.
文摘In this paper,numerical non-linear analyses of the “Guglie” bridge,located in the historical city of Venice(Italy),are proposed.The focus is twofold:on the sensitivity of the realized shape of the bridge by reference to originally designed shape;and on sensitivity to mechanical parameters of constituent materials.The history of this bridge is very interesting,and the bridge actually built is different from the Marchesini’s project(1580).In fact,in the original design drawing,the shape of the arch is a perfect circle arch,while the shape of the actually built arch is not perfectly circular.Hence,in the aim to evaluate sensitivity of bridge behaviour to designed and realized shape,non-linear analyses are carried on by means of FEMs(Finite Element Models)under in-plane state hypothesis.Furthermore,parametric tests are also performed for evaluating the influence of masonry mechanical parameters on non-linear bridge behaviour.
文摘Kathmandu World heritage buildings are made from low strength construction especially traditional bricks. From the lesson from 2015 Gorkha earthquake, saving those buildings in severe quake has been a challenging job. It requires proper assessment of its mechanical properties and strengthening as per seismic requirement. An investigation of mechanical properties on brick masonry heritage building has been done and presented here. Nondestructive test - elastic wave tomography at existing walls of the buildings and destructive tests shear, compression and combined loadings on the wallets made from bricks collected from old buildings The several test tests were conducted to find the properties of brick elements and walls such as, density, modulus of elasticity, Poisson’s ratio, shear modulus, shear wave velocity.
基金the United Arab Emirates University under research grant G00001603.
文摘On 26 th October 2015, an Mw 7.5 earthquake struck northern Pakistan, with its epicenter located 45 km southwest of Jarm in the Hindu Kush region of Afghanistan. The earthquake resulted from reverse faulting at a depth of 210 km, resulting in 280 fatalities and substantial damage to some 109,123 buildings. Regional seismicity, characteristics of recorded strong motions, damage statistics, and building performance observations are presented. Earthquake damage was mostly constrained to seismic-deficient unreinforced masonry(URM) buildings. Typical failure modes included toppled minarets, partial or complete out of plane collapse of URM walls, diagonal shear cracking in piers, flexural cracking in spandrels, corner damage, pounding damage, and damage due to ground settlement. The majority of human loss resulted due to failure of URM walls and subsequent roof collapse. URM buildings located in rural hilly areas closer to the epicenter suffered more intense and frequent damage than urban URM buildings located farther away in larger cities.