Slovak Journal of Civil Engineering最新文献_第2页

Hydraulic Calculations of a Telescopic Water Intake 伸缩式取水口的水力计算

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Slovak Journal of Civil Engineering Pub Date : 2023-06-01 DOI: 10.2478/sjce-2023-0013

A. Lipin, A. Sepahvand, N. Rustamova

{"title":"Hydraulic Calculations of a Telescopic Water Intake","authors":"A. Lipin, A. Sepahvand, N. Rustamova","doi":"10.2478/sjce-2023-0013","DOIUrl":"https://doi.org/10.2478/sjce-2023-0013","url":null,"abstract":"Abstract Telescopic water intake structures allow for the selective intake of water from the top layers of a reservoir. A telescopic water intake has a high degree of mobility, and a wide field of application; at the same time, it is very simple and convenient to operate. Despite these advantages, an exact calculation method for a telescopic water intake is lacking (Lipin, 2020; Lipin, 2022). Therefore, the purpose of this research is to develop an exact calculation method for a telescopic water intake. In order to perform this task, all the structural elements of a telescopic water intake were analyzed separately by means of existing hydraulic principles. The impact of the critical submergence depth of the water intake funnel on the operability of a telescopic water intake was studied, and an equation for the critical submergence depth calculation was proposed. The optimal range of the flow rate coefficient ( μ =0.30 - 0.45) was proposed for calculating the funnel flow rate, and the correlation between the flow rate and funnel inlet diameter was defined. The optimal curvature radius of the elbow was proposed. In order to verify the above mentioned parameters and correlations, analytical and numerical calculations of specific examples were performed. The results of the numerical modelling demonstrated that the critical submergence depth and shape of the water intake funnel, as defined by the analytical calculations, ensured its effective operation free of cavitation and vortexes. The analytically calculated dimensions of the telescopic column, following the numerical modelling results, provided normal hydraulic conditions without active cavitation. According to the numerical modelling, the proposed curvature radius of the elbow was sufficient to avoid significant cavitation and vortex formation in the elbow structure. This research can provide guidance for the design of telescopic water intake structures.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"61 - 69"},"PeriodicalIF":0.4,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41474310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Verification of the Ramberg-Osgood Material Model for the Fire Design of Steel Members 钢构件防火设计中Ramberg-Osgood材料模型的验证

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Slovak Journal of Civil Engineering Pub Date : 2023-06-01 DOI: 10.2478/sjce-2023-0008

Samer Nemer

{"title":"Verification of the Ramberg-Osgood Material Model for the Fire Design of Steel Members","authors":"Samer Nemer","doi":"10.2478/sjce-2023-0008","DOIUrl":"https://doi.org/10.2478/sjce-2023-0008","url":null,"abstract":"Abstract In this paper, the modified Ramberg-Osgood constitutive equations for calculating the stress-strain of steel at elevated temperatures using the parameters determined based on the transient state tensile test results achieved at the Helsinki University of Technology are verified. This is done by numerically comparing the global and local buckling capacities of I-shaped steel members incorporating the modified Ramberg-Osgood model along with the material model given in the fire section of Eurocode EN1993-1-2. For this purpose, a numerical model using the ABAQUS software was developed. Then, nonlinear analyses with imperfections (GMNIA) were performed to compare the buckling capacities of the steel columns and beams of four different hot-rolled cross-sections (IPE160, IPE180, HE100B, HE500B), made of steel grade S355, at three different temperatures (400°C, 500°C, 600°C). The results showed that adopting the modified Ramberg-Osgood model can lead to the same buckling capacities resulting when using the EN1993-1-2 material model for steel temperatures of less than 400°C. However, adopting this model for 600°C overestimates the buckling capacities in most cases.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"9 - 15"},"PeriodicalIF":0.4,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43377069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of Indoor Air Quality in a Kindergarten 某幼儿园室内空气质量分析

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Slovak Journal of Civil Engineering Pub Date : 2023-06-01 DOI: 10.2478/sjce-2023-0007

Petra Stiborova, Andrea Badurova, I. Skotnicova

引用次数: 0

Comparative Study of the Lightening of Concrete Through the Use of Recycled Tire Rubber and Expanded Clay Aggregate 再生轮胎橡胶与膨胀粘土骨料对混凝土轻量化的比较研究

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Slovak Journal of Civil Engineering Pub Date : 2023-06-01 DOI: 10.2478/sjce-2023-0009

R. Djebien, Rachid Kebout, Amel Bouabaz

{"title":"Comparative Study of the Lightening of Concrete Through the Use of Recycled Tire Rubber and Expanded Clay Aggregate","authors":"R. Djebien, Rachid Kebout, Amel Bouabaz","doi":"10.2478/sjce-2023-0009","DOIUrl":"https://doi.org/10.2478/sjce-2023-0009","url":null,"abstract":"Abstract The waste of tire rubber is characterized by the generation of huge amounts, which is annually discarded. This waste causes problems for human health and the environment. Thus, the valorization of recycled tire rubber in concrete production is considered as an alternative and sustainable solution. This experimental work is a comparative study, which aims to investigate the possibility of using recycled tire rubber as a fine aggregate in the production of lightweight concrete. To achieve this objective, two types of lightweight concrete containing (35, 70 and 100%) of expanded clay and (5, 10 and 15%) of recycled tire rubber as a fine aggregate were produced. Their fresh properties were investigated using slump, density and air content tests, while the hardened properties were investigated by compressive strength, flexural strength, ultrasonic pulse velocity, and water absorption tests. The results obtained showed that the utilization of both expanded clay aggregate and recycled tire rubber leads to a reduction in density and mechanical strength but increases the porosity of lightweight concrete. However, the lightweight concrete containing the expanded clay aggregate had a higher efficiency factor than those containing recycled tire rubber.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"16 - 24"},"PeriodicalIF":0.4,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41584603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Coarse Aggregate Rap Content on the Mechanical and Shear Performance of HMA by the UPT Method 用UPT法研究粗集料Rap含量对HMA力学和剪切性能的影响

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Slovak Journal of Civil Engineering Pub Date : 2023-06-01 DOI: 10.2478/sjce-2023-0014

M. Khabiri, Meysam Saboohi

{"title":"Effects of Coarse Aggregate Rap Content on the Mechanical and Shear Performance of HMA by the UPT Method","authors":"M. Khabiri, Meysam Saboohi","doi":"10.2478/sjce-2023-0014","DOIUrl":"https://doi.org/10.2478/sjce-2023-0014","url":null,"abstract":"Abstract In recent years, the use of materials derived from recycled asphalt has attracted the attention of airfield and highway construction researchers. Since the making of these products is economically cost-effective, one idea about how to use them is to use coarse-grained crumbs from recycled Asphalt Pavement (RAP), which are agglomerates that can be found in coarse RAP, as a replacement for virgin asphalt.The goal of the current study is to investigate the performance of hot mix asphalt created with various percents of RAP. The punching shear strength of cylindrical specimens versus the penetration of steel rods with fixed and determined diameters into an asphalt specimen is one of the tests used to study the shear strength of asphalt. Other typical tests include a test of the structural strength and resilient modulus with two rectangular and sinusoidal loading shapes, respectively, as well as the specimen's strength against different temperatures of asphalt mixtures containing 10, 20, and 30% coarse-grained RAP. The results show that the resilient strength of the samples with a maximum 30% coarse-grained RAP is within reasonable limits. Furthermore, the semi-sinusoidal loading has a higher resilience modulus than rectangular loading. It is also observed during uniaxial penetration testing (UPT) that increasing the RAP increases the penetration of the steel rod, thereby implying that the shear strength of the asphalt has decreased.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"70 - 78"},"PeriodicalIF":0.4,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48650117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Impact of Climate Change and Regulation of the Water Regime on the Morphological Structure of the Floodplain Forests in Petržalka, Slovakia 气候变化和水态调控对斯洛伐克Petržalka漫滩森林形态结构的影响

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Slovak Journal of Civil Engineering Pub Date : 2023-03-01 DOI: 10.2478/sjce-2023-0006

Viktória Gáspár, A. Škrinár

{"title":"The Impact of Climate Change and Regulation of the Water Regime on the Morphological Structure of the Floodplain Forests in Petržalka, Slovakia","authors":"Viktória Gáspár, A. Škrinár","doi":"10.2478/sjce-2023-0006","DOIUrl":"https://doi.org/10.2478/sjce-2023-0006","url":null,"abstract":"Abstract The main landscape-forming component has always been the forests in the lowlands. The devastation and disturbance of forest areas by anthropogenic activity change the ecological conditions in their environment. Climate and atmospheric changes affect the balance of the mutual relationships between individual components, as well as the existence of direct and feedback relationships in forest ecosystems. The transformation of bioclimatic and ecological conditions have caused the degradation of the Pannonian floodplain forest communities in Slovakia. Urbanization in Bratislava has caused the fragmentation of the surrounding forests. With changes in sunlight and heat conditions, flood-plain communities are forced to become acclimatized to drier conditions, which lead to morphological and structural changes in their composition. In this study we examined phytocenological records from 1999 to 2020 from various sources. The survey points to the impact of climate change and anthropogenic influences on biodiversity. The absence of floods and the drying of floodplain forest soils could have caused this change in the species' composition.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"52 - 57"},"PeriodicalIF":0.4,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44308752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hardening Accelerators (X-Seed 100 BASF, PCC, LKD and SALT) as Strength-Enhancing Admixture Solutions for Soil Stabilization 硬化加速剂(X-Seed 100 BASF, PCC, LKD和SALT)作为土壤稳定的强度增强添加剂溶液

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Slovak Journal of Civil Engineering Pub Date : 2023-03-01 DOI: 10.2478/sjce-2023-0002

P. Lindh, Polina Lemenkova

{"title":"Hardening Accelerators (X-Seed 100 BASF, PCC, LKD and SALT) as Strength-Enhancing Admixture Solutions for Soil Stabilization","authors":"P. Lindh, Polina Lemenkova","doi":"10.2478/sjce-2023-0002","DOIUrl":"https://doi.org/10.2478/sjce-2023-0002","url":null,"abstract":"Abstract This study is aimed at evaluating the strength of stabilised soil collected from the Port of Norvik, Stockholm, Sweden, where 350,000 m3 of clay had to be stabilized. The tests were performed in the laboratory of the Swedish Geotechnical Institute (SGI). The soil was stabilised by binder mixtures using Portland cement clinker (PCC) and lime and lime kiln dust (LKD). Accelerators (X-seed 100 BASF, PCC, LKD and salt) were added to the soil samples for quicker stabilization. The strength of the stabilised soil was assessed using resonance frequency measurements of seismic P-waves by an ICP accelerometer in order to estimate the shear strength of the soil and to evaluate the effects from the accelerators, binder ratios, and the curing temperature on the gains in stabilization and strength. Various proportions of the binders were tested, i.e.: 50/50 cement/lime and 50/50 PCC/lime. The temperature was measured using a calorimeter in double experiments. The results showed that the accelerators improve the strength in the stabilized specimens and enhance the soil performance for engineering construction work.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"31 1","pages":"10 - 21"},"PeriodicalIF":0.4,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48264116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Physical-Mechanical Properties of Waterproofing Materials Applied to Roofs in the Context of UV Degradation 紫外线降解条件下屋顶防水材料的物理力学性能

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Slovak Journal of Civil Engineering Pub Date : 2022-12-01 DOI: 10.2478/sjce-2022-0027

Jozef Kováč, M. Palko, A. Kleinová

引用次数: 0

Redesign of an Intake Fish Pass Structure 进气鱼道结构的重新设计

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Slovak Journal of Civil Engineering Pub Date : 2022-12-01 DOI: 10.2478/sjce-2022-0028

L. Čubanová, P. Dusicka, Martin Orfánus, J. Rumann

引用次数: 1

Comparative Study of Lightweight Concretes Based on Hemp and Flax Straw 大麻与亚麻秸秆轻质混凝土的对比研究