U. Jain
info
Please Note
<p>This page displays the records of the person named above and is not linked to a unique person identifier. This record may need to be merged to a profile.</p>
4 records found
1
Extracting cores with diameters of 100 to 150 mm from masonry structures has emerged as a novel, less destructive method for assessing the mechanical properties of masonry units, particularly their compressive strength. Unlike traditional methods, such as using larger wallets, this approach requires less material and causes minimal damage to the original structure, which is critical when dealing with historical buildings. However, to obtain consistent and reliable results, certain parameters, specifically the dimensions of the core cap, must be carefully defined, as they significantly influence the overall behaviour of the samples. The study employs a detailed block-based modelling approach, incorporating zero-thickness cohesive elements at the brick-mortar interfaces. Additionally, tangential and normal contact interactions were defined between the cap and core components. The concrete damage plasticity (CDP) model, implemented in ABAQUS, has been adopted as the constitutive model to account for the nonlinear behaviour of brick, mortar, and cap. The results indicate that the length of the cap has a more pronounced effect on the sample’s mechanical behaviour than its height. Additionally, the study investigates the mechanical properties of the interface between the cap and the core, identifying friction and normal stiffness as critical factors. These findings provide valuable insights for optimizing the core capping process and improving the reliability of masonry mechanical property assessments, particularly in the preservation of historical structures.
...
Extracting cores with diameters of 100 to 150 mm from masonry structures has emerged as a novel, less destructive method for assessing the mechanical properties of masonry units, particularly their compressive strength. Unlike traditional methods, such as using larger wallets, this approach requires less material and causes minimal damage to the original structure, which is critical when dealing with historical buildings. However, to obtain consistent and reliable results, certain parameters, specifically the dimensions of the core cap, must be carefully defined, as they significantly influence the overall behaviour of the samples. The study employs a detailed block-based modelling approach, incorporating zero-thickness cohesive elements at the brick-mortar interfaces. Additionally, tangential and normal contact interactions were defined between the cap and core components. The concrete damage plasticity (CDP) model, implemented in ABAQUS, has been adopted as the constitutive model to account for the nonlinear behaviour of brick, mortar, and cap. The results indicate that the length of the cap has a more pronounced effect on the sample’s mechanical behaviour than its height. Additionally, the study investigates the mechanical properties of the interface between the cap and the core, identifying friction and normal stiffness as critical factors. These findings provide valuable insights for optimizing the core capping process and improving the reliability of masonry mechanical property assessments, particularly in the preservation of historical structures.
Historical masonry quay walls in the inner city of Amsterdam need maintenance due to aging, and deterioration of foundations. These structures are not only critical to the transport infrastructure of the city, but also hold great heritage and monumental value being UNESCO World Heritage site. However, there is a notable lack of knowledge and documentation regarding the mechanical properties of these multi-wythe, unreinforced brick masonry walls, which poses challenges to the assessment of their structural safety. This research investigates the mechanical properties of masonry for typical quay walls presenting the results of experiments for four different quay wall locations in Amsterdam. Masonry properties were determined via core testing due to its minimal invasiveness to the structure and its ability to adopt standard extraction and testing facilities. Companion tests on brick and mortar were performed to evaluate their compressive properties. Samples were obtained from both above and below the waterline to assess the effect of submersion on the mechanical properties. This study offers an insight into the mechanical properties of quay walls in Amsterdam, enhancing understanding of multi-wythe masonry and supporting the assessment and preservation of urban infrastructure in Dutch cities.
...
Historical masonry quay walls in the inner city of Amsterdam need maintenance due to aging, and deterioration of foundations. These structures are not only critical to the transport infrastructure of the city, but also hold great heritage and monumental value being UNESCO World Heritage site. However, there is a notable lack of knowledge and documentation regarding the mechanical properties of these multi-wythe, unreinforced brick masonry walls, which poses challenges to the assessment of their structural safety. This research investigates the mechanical properties of masonry for typical quay walls presenting the results of experiments for four different quay wall locations in Amsterdam. Masonry properties were determined via core testing due to its minimal invasiveness to the structure and its ability to adopt standard extraction and testing facilities. Companion tests on brick and mortar were performed to evaluate their compressive properties. Samples were obtained from both above and below the waterline to assess the effect of submersion on the mechanical properties. This study offers an insight into the mechanical properties of quay walls in Amsterdam, enhancing understanding of multi-wythe masonry and supporting the assessment and preservation of urban infrastructure in Dutch cities.
Masonry quay walls are vital infrastructure in many historic cities, serving both functional and historical purposes. Originally designed as gravity retaining walls, they now face increased vehicle loads and widespread material degradation, particularly in timber foundations. Traditional assessment methods are often overly conservative, lacking standard procedures for multi-wythe masonry characterisation.With over 200 km of quay walls in Amsterdamrequiring renovation, there is an urgent need for practical, reliable assessment methods. This paper provides an overview of recent research conducted at TU Delft with focus on the response of masonry superstructure, presenting and discussing key advancements in the development of high-fidelity static and dynamic finite element models and minor-destructive testing for masonry mechanical property characterisation.
...
Masonry quay walls are vital infrastructure in many historic cities, serving both functional and historical purposes. Originally designed as gravity retaining walls, they now face increased vehicle loads and widespread material degradation, particularly in timber foundations. Traditional assessment methods are often overly conservative, lacking standard procedures for multi-wythe masonry characterisation.With over 200 km of quay walls in Amsterdamrequiring renovation, there is an urgent need for practical, reliable assessment methods. This paper provides an overview of recent research conducted at TU Delft with focus on the response of masonry superstructure, presenting and discussing key advancements in the development of high-fidelity static and dynamic finite element models and minor-destructive testing for masonry mechanical property characterisation.
Masonry structures occupy a significant share of the current building stock due to widespread material availability and cost-effectiveness. Regions with high seismicity, such as the Himalayas, have often developed a local seismic culture over the centuries. This has led to improved construction techniques providing an enhanced seismic performance, as evident from post-earthquake surveys in this area. In this framework, Bhatar is a building typology found in the greater Himalayan region, which features embedded horizontal timber bands in masonry walls, enhancing the box-behaviour and in turn avoiding their premature out-of-plane failure. This work aims to quantify the improvement of the out-of-plane performance of masonry walls because of the presence of horizontal timber bands. In order to achieve this research objective, numerical analyses were conducted in DIANA FEA finite element software starting from the few experimental results on this building typology available in the literature. These were used to calibrate the properties of masonry, which was represented as a homogeneous isotropic continuum, with nonlinearities taken into account by means of a total strain rotating crack model. Firstly, a U-shaped masonry wall having the same geometry and boundary conditions as the experimental tests was simulated using a 3D modelling approach. Non-linear static analyses were performed and very good agreement was obtained with the results from the literature. On this basis, the calibrated numerical model was then employed to conduct sensitivity analyses considering varying factors, such as masonry material properties, geometry, opening configurations, timber section sizes and properties. The outcomes of this extensive study show a considerable improvement in the out-of-plane response of the masonry walls in the presence of horizontal timber bands. Given the limited research conducted on the Bhatar building typology in the past, this work constitutes a further step towards a better understanding of the behaviour of Himalayan masonry structures under earthquakes, promoting more effective seismic risk reduction strategies. This improved understanding into timber’s role in imparting greater seismic resilience to masonry structures can inform better maintenance, conservation and preservation of heritage and historical masonry structures in the Himalayas.
...
Masonry structures occupy a significant share of the current building stock due to widespread material availability and cost-effectiveness. Regions with high seismicity, such as the Himalayas, have often developed a local seismic culture over the centuries. This has led to improved construction techniques providing an enhanced seismic performance, as evident from post-earthquake surveys in this area. In this framework, Bhatar is a building typology found in the greater Himalayan region, which features embedded horizontal timber bands in masonry walls, enhancing the box-behaviour and in turn avoiding their premature out-of-plane failure. This work aims to quantify the improvement of the out-of-plane performance of masonry walls because of the presence of horizontal timber bands. In order to achieve this research objective, numerical analyses were conducted in DIANA FEA finite element software starting from the few experimental results on this building typology available in the literature. These were used to calibrate the properties of masonry, which was represented as a homogeneous isotropic continuum, with nonlinearities taken into account by means of a total strain rotating crack model. Firstly, a U-shaped masonry wall having the same geometry and boundary conditions as the experimental tests was simulated using a 3D modelling approach. Non-linear static analyses were performed and very good agreement was obtained with the results from the literature. On this basis, the calibrated numerical model was then employed to conduct sensitivity analyses considering varying factors, such as masonry material properties, geometry, opening configurations, timber section sizes and properties. The outcomes of this extensive study show a considerable improvement in the out-of-plane response of the masonry walls in the presence of horizontal timber bands. Given the limited research conducted on the Bhatar building typology in the past, this work constitutes a further step towards a better understanding of the behaviour of Himalayan masonry structures under earthquakes, promoting more effective seismic risk reduction strategies. This improved understanding into timber’s role in imparting greater seismic resilience to masonry structures can inform better maintenance, conservation and preservation of heritage and historical masonry structures in the Himalayas.