design standards
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2022 ◽  
Vol 12 (1) ◽  
pp. 503
Author(s):  
João Leite ◽  
Paulo B. Lourenço ◽  
Nuno Mendes

Several factors influence the behaviour of masonry infilled frames, which have been the subject of previous research with moderate success. The new generation of European design standards imposes the need to prevent the brittle collapse of infills and makes the structural engineer accountable for this requirement, yet it fails to provide sufficient information for masonry infill design. The present study aimed to compare experimental results with the provisions of the standard for the computation of the demand and capacity of infilled frames. Three reinforced concrete buildings with different infill solutions were constructed at a 1:1.5 scale. The infill walls were tested until collapse, or severe damage, using the shake table of the National Laboratory for Civil Engineering, Portugal, and their response was measured using accelerometers attached to the walls. The European normative standard provides results close to the experimental ones as far as demand and capacity are concerned. Based on the experiments, two design proposals for infill walls are presented here, one for the definition of the natural frequency of the infills, and another for a reduction factor to account for the presence of openings in the out-of-plane capacity of infills.


2022 ◽  
Vol 2153 (1) ◽  
pp. 012004
Author(s):  
J F Márquez-Peñaranda ◽  
J R Pineda-Rodríguez ◽  
J P Rojas-Suárez

Abstract Bridges represent an important application of physics capable of solving real transportation problems. Knowledge of convenience of different mechanical solutions when analyzing and designing bridge is needed. For these reasons, this work is focused on the study of convenience of using two types of bridges. Simply supported short-medium span bridges (30 m to 45 m) are usually excessively long when choosing reinforced concrete solutions and usually short for other types of structures such as cable-stayed or cantilever bridges. The suitability of simply supported bridges leads to the need of studying their cost benefit ratios. This work studies the cost benefit ratio for post-tensioned concrete beams and structural steel girders in simply supported straight bridges. Eight models built of type I sections were used in both cases to analyze the bridges using a software based on the stiffness method. Span of each bridge was set to 30 m, 35 m, 40 m, and 45 m. The convenience of each type of bridge was done comparing the total and the cost per linear meter of each solution (post-tensioned and structural steel). Comparison was done using material consumption, labor, and construction processes costs only. Also, allowable vertical displacement given by current bridge design standards was verified.


2021 ◽  
Vol 21 (6) ◽  
pp. 303-311
Author(s):  
Dong Jun Kim ◽  
Kyung Min Choi ◽  
Yang Ho Song ◽  
Jung Ho Lee

The rise in average sea level due to climate change aggravates the vulnerability of coastal areas, increasing the likelihood of flooding due to erosion of outfall to the coast and rivers. Therefore, the design standards of defense facilities should be strengthened to address such increased risk of flooding. Accordingly, in this study, a plan to adjust the disaster prevention performance target rainfall for two research areas was selected in consideration of the regional characteristics of the coastal area and the average sea level rise predicted for 2050, and the disaster prevention performance target rainfall increased from at least 89% to up to 169%. Based on these results, it is believed that this study can serve as a basis for improving data on rainfall targets for disaster prevention performance with consideration of future sea level rise in coastal cities.


Author(s):  
Armagan Altinisik ◽  
Emre Bolova

The prediction model for the energy contributors is studied to define the effect of door components. The model is validated by experimental measurements on produced vehicles. The correlation of the control results and the evaluation methods among the representative customers, appraisers and senior experts are performed and compared by objective energy measurements. The subjective evaluation aims to clarify real customer expectations in door closing process and carry it to new product development phase. This will also improve the competency of appraisers in final assembly approval zones. The energy contributors for boot swing door is numerically calculated and validated by experimental measurements in easy and hard-closing doors. Subjective evaluations in 45 vehicles with different closing energies were performed by three different groups as representative customers, appraisers, and senior experts. The results were evaluated by statistical tools. The major energy contributors were found as air binding, seal resistance and check strap both in the calculations and in the experiments. The results demonstrated good correlation between numerical model and objective measurements. Besides, the subjective evaluations showed parallel trends with objective energy measurements. The variation in customer evaluations is more than appraisers and experts. Customers are severer in the evaluations of hard-closing doors and more sensitive in 10° door closing angle. This is a unique study for rear boot swing door closing effort in an LCV model. The study contains both definitions of factors, components that contributes in door closing energy and subjective evaluations to correlate the closing behaviors of representative customers, appraisers, and senior experts. The output of the study would be used to improve the vehicle control plan (VCP) and design standards in new model development phase.


Author(s):  
Megha Bhatt ◽  
◽  
Sandip A. Vasanwala ◽  

Reinforced concrete chimneys are tall industrial structures specially used in power plants to expel waste gases at high enough elevation. Based on the study of various literature available for the subject, various geometrical, material, and loading parameters to be followed to prepare the test specimens are presented in this paper so that the test specimen represents the behaviour of the actual RC chimney. The special construction process required to be followed is described in this paper along with the various analytical checks to be performed before the actual application of lateral loads on test specimens. Different design standards give different design recommendations mainly in terms of the stress-strain curve of concrete and steel. So, various experimental tests performed by applying the lateral load on specially designed and casted test specimens which represents the actual chimney in the field helps the researchers to compare the various design standards and helps the industry to opt for the same.


2021 ◽  
pp. 074193252110636
Author(s):  
So Yeon Kim ◽  
Mandy Rispoli ◽  
Rose A. Mason ◽  
Catharine Lory ◽  
Emily Gregori ◽  
...  

Technology has been widely used to teach reading skills to students with autism spectrum disorder (ASD), but the quality of research backing up this practice has not yet been fully investigated. The purpose of this review was to examine the quality of research on technology-aided reading interventions for students with ASD and summarize study characteristics of research studies with meeting the What Works Clearinghouse (WWC) design standards. A total of 31 studies using group design ( n = 4) or single-case design ( n = 27) were systematically aggregated, and 16 studies (52%) met the WWC design standards. Study features related to participants, intervention, technology usage, and outcome variables were synthesized for these 16 studies. Results indicated that two types of technology (i.e., computer, iPad) were used to deliver reading instruction through software programs or support interventionist-directed reading instruction. Finally, implications for research and practice are discussed.


Author(s):  
I. I. Vedyakov ◽  
D. V. Konin ◽  
A. A. Egorova ◽  
I. V. Rtishcheva

The present work provides an overview and analysis of scientific, technical, regulatory, and methodical Russian and foreign literature regarding using glass as a material for load-bearing structures of buildings. In the absence of design standards, an experimental study of usually one or two samples is necessary each time glass structure is used; however, this is insufficient to determine the distinct pattern of material performance. Since jointing the glass structures has been rarely studied, the number of tests is minimal, thus preventing establishing the unambiguous material operation and its calculated physical and mechanical characteristics. The article considers and evaluates the test results of glass structures obtained by various methods. The particular values of ultimate stresses and deformation modulus lie in a wide range. The technology, manufacturing process, and starting materials have a significant influence on the characteristics of glass, including multilayer glass. This article stresses the need for developing regulatory technical and methodical documents, the design and testing standards for glass structures and their jointing. It is necessary to classify load-bearing glass structures by various criteria.


2021 ◽  
Author(s):  
Fabiana Castino ◽  
Bodo Wichura ◽  
Harald Schellander ◽  
Michael Winkler

<p>The characterization of the snow cover by snow water equivalent (SWE) is fundamental in several environmental applications, e.g., monitoring mountain water resources or defining structural design standards. However, SWE observations are usually rare compared to other snow measurements as snow depth (HS). Therefore, model-based methods have been proposed in past studies for estimating SWE, in particular for short timescales (e.g., daily). In this study, we compare two different approaches for SWE-data modelling. The first approach, based on empirical regression models (ERMs), provides the regional parametrization of the bulk snow density, which can be used to estimate SWE values from HS. In particular, we investigate the performances of four different schemes based on previously developed ERMs of bulk snow density depending on HS, date, elevation, and location. Secondly, we apply the semi-empirical multi-layer Δsnow model, which estimates SWE solely based on snow depth observations. The open source Δsnow model has been recently used for deriving a snow load map for Austria, resulting in an improved Austrian standard. A large dataset of HS and SWE observations collected by the National Weather Service in Germany (DWD) is used for calibrating and validating the models. This dataset consists of daily HS and three-times-a-week SWE observations from in total ~1000 stations operated by DWD over the period from 1950 to 2020. A leave-one-out cross validation is applied to evaluate the performance of the different model approaches. It is based on 185 time series of HS and SWE observations that are representative of the diversity of the regional snow climatology of Germany. Cross validation reveals for all ERMs: 90% of the modelled SWE time series have a root mean square error (RMSE) and a bias lower than 45 kg/m² and 2 kg/m², respectively. The Δsnow model shows the best performance with 90% of the modelled SWE time series having an RMSE lower than 30 kg/m² and bias similar to the ERMs. This comparative study provides new insights on the reliability of model-based methods for estimating SWE values. The results show that the Δsnow model and, to a lower degree, the developed ERMs can provide satisfactory performances even on short timescales. This suggest that these models can be used as reliable alternative to more complex thermodynamic snow models, even more if long-term meteorological observations aside HS are scarce.</p>


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