1,721,872 research outputs found
IP-OOP interaction in URM infilled frame structures: A new macro-modelling proposal
No full textReinforced concrete frame structures with unreinforced masonry (URM) infills represent a common construction practice all over the world. To correctly assess the seismic performance of these structures, prediction of the behaviour of masonry infills under in-plane (IP) and out-of-plane (OOP) loading, as well as their interaction, is of primary importance. Different approaches are available in the literature with different levels of approximation for assessment of the IP-OOP infill response, showing increasing interest in this field. In this context, this paper presents a new macro-element model which can simulate the behaviour of URM infill walls under seismic IP and OOP actions. The model is the evolution of an approach based on a 4-strut configuration characterized by one horizontal strut, one vertical strut and two diagonal struts representing the infill wall. The struts are modelled by fibre-section beam-column elements and their compressive behaviour is defined by empirical strength and strain parameters. The paper also presents some equations to obtain the empirical parameters mentioned, based on the actual mechanical properties of infill walls. In the paper, the validation of the proposed model with the experimental results available in the literature is discussed. Further, the improved capacity to simulate the arching mechanism in infill walls under OOP loads and the better reliability in capturing the interaction between the IP and OOP behaviours are described
Laser Scanning Systems in Highway and Safety Assessment Analysis of Highway Geometry and Safety Using LiDAR
No full textAnalysis of Highway Geometry and Safety Using LiDAR Biswajeet Pradhan,
Maher Ibrahim Sameen. fusion and optimization. ISPRS Journal of
Photogrammetry and Remote Sensing, 118, 22–36. Idrees, M. O., & Pradhan, B. (
2016). A decade ..
Artificial intelligence and spatial Modelling in natural hazards and environmental applications
No full textModeling and predicting geohazards is extremely difficult due to their complex behavior in the real-world. In fact, several aspects of these environmental applications are considered in computer-based modeling to accurately estimating real-world phenomena. Till date, none of the proposed methods have reached to zero uncertainties or errors to recognize the entire disaster’s events. Globally, many people have lost their lives due to various types of natural hazards. Therefore, it is important to detect, monitor and predict them to protect the inhabitants against the potential natural hazards that threaten human lives and properties. Recently, artificial intelligent (AI) methods have received a great deal of attraction due to their precision to model the complex problems such as natural hazards. AI can see different aspects of a complex problem with sufficient iteration and details. In recent years, implementation of AI models coupled with geospatial information systems (GIS) are the most efficient and accurate approach to model natural disasters i.e. flooding, earthquake, landslides, forest fire and drought rather than other existing methods. This gives an insight into the ability of applied AI models in some natural hazards applications
Out-of-Plane Behavior of URM Infill: Accuracy of Available Capacity Models
No full textThe aim of this paper is to check the accuracy of analytical capacity models available for the prediction of out-of-plane strength of unreinforced masonry (URM) infill walls. The accuracy of the available models is checked by detailed comparison with the existing experimental results. In doing so, both types of capacity models are evaluated: Type I for the prediction of the strength in the undamaged state, and Type II for the prediction of strength reduction in the in-plane damaged state. Results from the calculations are discussed, and the best among the available models are recommended. Furthermore, the influence of orthotropy of the infill masonry in the out-of-plane capacity predicted by the models is discussed. The paper also highlights the prospect of using the capacity models in the cases of infill-beam gap and infill with openings. In the paper, the best pairs of models (composed by a model for the prediction of the out-of-plane strength in the undamaged state and a model for the prediction of the reduction of the out-of-plane strength in the damaged state, not necessarily provided by the same author) for URM infill walls, are suggested for the first time
Out-of-Plane fragility of In-Plane damaged unreinforced masonry infills in low rise reinforced concrete buildings
No full textUnreinforced masonry (URM) is commonly used to make infill walls in reinforced concrete (RC) frame buildings. Such infill walls are highly vulnerable to out-of-plane (OOP) seismic loading and this can result in huge economic losses and human casualties. Therefore, fragility assessment of URM infill walls under seismic loads is important in view of performing large-scale risk analysis. In this paper, OOP fragility functions are provided based on a numerical investigation supported by a macro-element model. The fragility is calculated assuming the uncertainty in the geometric and mechanical properties of infills instead of the variability in the seismic input. Further, the effect of in-plane (IP) and out-of-plane (OOP) interaction is taken into account. Finally, the sensitivity of the results to the infill position in low rise buildings is discussed. Experimental data available in the literature are used for the validation of the output. Overall, the results indicated lower vulnerability in the OOP direction for infill walls without IP damage and high vulnerability in the OOP direction in the presence of previous IP damage. The vulnerability was found also increasingly proportional to the positioning of the panels at higher floors where the spectral acceleration of the structure is higher too. The proposed procedure can be extended to other types of infill walls depending on the construction technique of the site of interest, obtaining different and specific fragility curves for large-scale risk analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Out-of-plane behaviour of unreinforced masonry infill walls: Review of the experimental studies and analysis of the influencing parameters
Full text linkOver the last 50 years, research has mainly focused on characterizing the In-Plane behaviour of unreinforced masonry infill walls. Recently, the focus of research has been addressed to understanding Out-of-Plane behaviour, also from the experimental point of view. However, in the experimental campaigns, there is high variability in the geometrical and mechanical properties of URM infill walls and also in the application of Out-of-Plane loads. Therefore, it is important to outline and critically evaluate the major findings obtained by experimental studies and identify research gaps to better understand the differences and the affinity of apparently equivalent tests. In this paper, the extensive literature regarding the Out-of-Plane tests on infill walls has been reviewed with a detailed comparison of the experimental results based on different influencing parameters (slenderness ratio, aspect ratio, boundary conditions, openings, vertical load. In-Plane damage, strength of masonry and plaster, frame stiffness). Based on the study, the main areas that demand further experimental campaigns have been identified and recommended
Investigation of aqueous and light non-aqueous phase liquid in fractured double-porosity soil
No full textThe issue of leakage and spillage of light non-aqueous phase liquids (LNAPLs) and aqueous phase liquids (APLs) contribute to groundwater contamination, resulting in groundwater pollution and rendering the quality of groundwater unsafe for drinking and agricultural use. This paper aimed to investigate the APL and LNAPL in the deformable double-porosity soil, which has become important for sustainability of groundwater utilization and a comprehensive understanding of the characteristics of APL and LNAPL migration into the groundwater through the use of digital image processing techniques. The results of the experiments show that the flow of the APL and LNAPL migration was not uniformly downward. Faster migration occurred at the cracked soil surface condition compared to other locations on the soil surface that were not cracked, even when not using a liquid such as toluene. It was concluded that the factors that significantly influenced the APL and LNAPL migration was the soil sample structure, soil sample fracture pattern, physical interaction bonding between the liquid and soil sample, and capillary pressure of the fluid. The output of this study indicates that digital image analysis can provide detailed information to enable researchers to have better understanding and simulating the pattern of liquids migration characteristics that influence the groundwater resources
A review on soil erosion control studies
No full textSoil erosion resulting from heavy rainfall, depends on a number of factors, such as the native soil properties (the angle of internal friction, cohesion, unit weight, etc.), hydraulic conditions (surface runoff, groundwater seepage, etc.), the removal of vegetation and change in the surrounding environment. This study investigated the preliminary factors that could cause Soil erosion and detailed the literature through an exhaustive review of the previous published materials on the field and laboratory research works dealing with the soil erosion control techniques
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