Stavební obzor - Civil Engineering Journal最新文献_第2页

FUNCTIONAL USE OF THE AREA OF PRAGUE CASTLE WITH EMPHASIS ON THE NORMALIZATION PERIOD 功能区的使用强调了布拉格城堡的正常化时期

Stavební obzor - Civil Engineering Journal Pub Date : 2023-07-31 DOI: 10.14311/cej.2023.02.0019

Martin Šnorbert

{"title":"FUNCTIONAL USE OF THE AREA OF PRAGUE CASTLE WITH EMPHASIS ON THE NORMALIZATION PERIOD","authors":"Martin Šnorbert","doi":"10.14311/cej.2023.02.0019","DOIUrl":"https://doi.org/10.14311/cej.2023.02.0019","url":null,"abstract":"This paper deals with individual typological types and units in the Prague Castle area. It also focuses on the urban and historical development, as it is significantly influenced by the situation in the period under study. It focuses more closely on the period of the second half of the 20th century, and especially the period of normalization - the 1970s and 1980s.\u0000Prague Castle was and still is the seat of the monarch, or today the President of the Czech Republic. The historical context has had a considerable influence on the shape of the Castle (the succession of ruling personalities from different dynasties, the transformation from the position of the seat of the Habsburg monarchy and therefore the most important center in Central Europe to the position of the summer residence of the ruling family, etc.). Also unprecedented is the concentration of the main buildings of secular and ecclesiastical power in one area. The castle is a huge complex, combining morphological assumptions with the result of the work of a huge number of people. A number of foreign artists worked here, reaching world-class standards and both understanding and supporting the local genius loci. There are also many contrasts - political and constructional. For example, the imprints of monarchy and republic, church and secular power, ancient and modernist architecture, contrasts between the smallest buildings of houses and the largest palaces.\u0000On the basis of archival research and the study of expert literature, the reader is introduced to the progressive changes in the layout of the Castle complex and the associated changes in the functional use of the buildings and spaces in the aforementioned complex.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86005989","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

FRICTION TEST AND PARAMETER ANALYSIS OF PRESTRESSED CONCRETE CONTINUOUS BEAM BRIDGE 预应力混凝土连续梁桥摩擦试验及参数分析

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0005

Qingxin Yu, Quansheng Sun, Junyun Liu

{"title":"FRICTION TEST AND PARAMETER ANALYSIS OF PRESTRESSED CONCRETE CONTINUOUS BEAM BRIDGE","authors":"Qingxin Yu, Quansheng Sun, Junyun Liu","doi":"10.14311/cej.2023.01.0005","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0005","url":null,"abstract":"The prestressed ducts of prestressed concrete continuous girder bridges are usually three-dimensionally distributed and long in length. The control of prestress loss during construction is very important. In order to ensure the effect of prestress tensioning, the test and analysis of friction parameters of prestressed ducts are particularly important. Based on the tension process of a prestressed concrete continuous beam bridge, the initial tension stress, loading time and channel friction parameters of the prestressed concrete continuous beam bridge are tested by field tests. Combined with the measured friction parameters, the finite element software Midas / Civil is used to analyse the influence of friction parameters on the mechanical properties of prestressed concrete continuous beam bridge. The results show that when the prestressed steel with bending angle not more than 40° and length not more than 70 m is stretched, the initial tension stress is suggested to be set as 20 % of the tension control force and the loading time is 5 min. The measured tunnel friction parameters are larger than the standard value, and the tension control force should be adjusted during the formal tension construction；The deflection of the key section of the main beam increases with the increase of the friction parameters, and the roof stress decreases with the increase of the friction parameters. The change of channel deviation coefficient has a greater impact on the deflection and roof stress than the change of friction coefficient.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77824073","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

AN INVESTIGATION OF DAMPING MODIFICATION FACTORS CORRESPONDING TO DIFFERENT DAMPING RATIOS FOR SDOF SYSTEMS sdof系统不同阻尼比下阻尼修正因子的研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0004

E. Çelik, Onur Merter

{"title":"AN INVESTIGATION OF DAMPING MODIFICATION FACTORS CORRESPONDING TO DIFFERENT DAMPING RATIOS FOR SDOF SYSTEMS","authors":"E. Çelik, Onur Merter","doi":"10.14311/cej.2023.01.0004","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0004","url":null,"abstract":"The damping ratio is an important parameter in dynamic analyses and plays a key role in the design of building structures. Elastic response spectra are widely used in this design to describe the earthquake action in specific site classes. 5% damped response spectra are generally used for most of the conventional structures. However, other types of structures may not have a damping ratio of 5% and can have much lower or much larger damping ratios. The damping ratio is recommended at about 5% for concrete structures whereas it is estimated at 2% for steel structures. Tall slender buildings may have much lower damping ratios and low-rise buildings may be designed using much larger damping ratios than 5%. For these types of buildings, elastic response spectra are modified to account for different levels of damping ratios. This study proposes the damping modification factors (DMFs) which are computed using 5% response spectra as the benchmark. A strong ground motion set has been selected for the stiff site class and the displacement, pseudo-velocity, and pseudo-acceleration response spectra have been computed for single-degree-of-freedom (SDOF) systems. DMFs have been obtained in terms of these spectra and 3%, 10%, 20%, and 30% damping ratios have been considered. Variations of DMFs with different damping ratios have been obtained graphically. It can be seen from the results that DMFs are sensitive to the vibration period of the SDOF system.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78876231","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

DETERMINATION OF DESIGN PARAMETERS OF ASPHALT PAVEMENT BASED ON PG TECHNOLOGY 基于pg技术的沥青路面设计参数的确定

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0003

Haitao Zhang, Meiyi Gao, Shengsheng Ma, Huizhong Xiong

引用次数: 0

RESEARCH AND APPLICATION OF U-BIT CONSTRUCTION METHOD IN SUBWAY STATION ENGINEERING LOCATED IN SATURATED SOFT SOIL AREA u-bit施工方法在饱和软土地区地铁车站工程中的研究与应用

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0009

Yan Guo, Yanfei Zhu, W. Pan, Yeon-Ho Jin

{"title":"RESEARCH AND APPLICATION OF U-BIT CONSTRUCTION METHOD IN SUBWAY STATION ENGINEERING LOCATED IN SATURATED SOFT SOIL AREA","authors":"Yan Guo, Yanfei Zhu, W. Pan, Yeon-Ho Jin","doi":"10.14311/cej.2023.01.0009","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0009","url":null,"abstract":"In order to solve the problems existing in the construction of underground structures located in the downtown of saturated soft soil area, such as insufficient construction site, complex adjacent structures and great impact on the surrounding environment, the construction method of underground bundled integrate tunnel(U-BIT) is proposed. In this method, after steel pipes jacking completed, concrete is filled into the pipes, and prestress is tensioned to make each independent pipe combined to form a whole bearing structure, so as to achieve the purpose of reducing the size of structural components, improving the structural stiffness and bearing capacity. Based on the structural mechanical properties test and the project of Wuding Road Station of Shanghai Metro Line 14, the failure mechanism of bundled integrate structure, the tension technology of prestressed tendons in narrow space and the variation rules of ground surface subsidence are systematically studied. The research shows that structural seam sections will be destroyed before pipe sections, so ensuring the mechanical performance of seam sections is very important to make sure the structural safety. Since each independent pipe is combined to form an overall stable structure under the prestress effect, the subsequent soil excavation has little influence on the tension of prestressed tendons and ground surface deformation. Therefore, the above construction method can control the ground surface subsidence effectively and reduce the influence of underground engineering construction on the surrounding environment. ","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76943474","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

EXPERIMENTAL INVESTIGATION OF PERVIOUS CONCRETE TO IMPEL IT IN THE INFRASTRUCTURE OF PAKISTAN 透水混凝土在巴基斯坦基础设施中的推广试验研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0007

Madiha Shamim Madiha, Hira Shakeel Hira, Shafaq Naseer Shafaq

{"title":"EXPERIMENTAL INVESTIGATION OF PERVIOUS CONCRETE TO IMPEL IT IN THE INFRASTRUCTURE OF PAKISTAN","authors":"Madiha Shamim Madiha, Hira Shakeel Hira, Shafaq Naseer Shafaq","doi":"10.14311/cej.2023.01.0007","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0007","url":null,"abstract":"Pakistan is facing adverse environmental issues peculiarly in major cities. The condition gets worst during monsoon period when the whole city faces the urban flooding due to stagnation of storm water on all major streets and areas. The main reason is the lack of infra-structure to mitigate the crisis which is faced by the country during whole rainfall season. The introduction of Pervious Concrete in major pavement infra-structure can easily limit the problems of sump of rain water. As a part of road infrastructure, the upper layer of pavement can be pervious, making runoff water to move to sub-base. This paper offers the exploratory research to ascertain the compressive strengths and infiltration rate of different samples of Porous Concrete following the American Concrete Institute guidelines. The experiments were done with varying the properties of Pervious Concrete. The effects which were considered are curing time, mix proportion, percentage quantity of fine aggregate, ratio of water to cement and varying coarse aggregate size. The mix design ratio considered were 1:4, 1:5 and 1:6. For further experiment of infiltration rate, the custom slab was formed with dimensions 2’x1’x4” and was tested for all the desired ratios. For the purpose of cost comparison, a fixed size on land is kept as standard. The cost is compared for construction on the land, using three different materials: Pervious concrete, Traditional concrete and Asphalt premix.It was showed that the Traditional concrete is cheaper than the Pervious and Asphalt layer but Pervious concrete is also economical than Asphalt layer.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84095081","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

Research on a safety evaluation system for railway-tunnel structures by fuzzy comprehensive evaluation theory 基于模糊综合评价理论的铁路隧道结构安全评价体系研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0010

Yanfeng Li, Jialong Li, Jihe Zhao, Tongfeng Zhao, Dong Guo

{"title":"Research on a safety evaluation system for railway-tunnel structures by fuzzy comprehensive evaluation theory","authors":"Yanfeng Li, Jialong Li, Jihe Zhao, Tongfeng Zhao, Dong Guo","doi":"10.14311/cej.2023.01.0010","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0010","url":null,"abstract":"Long-term health detection of railway-tunnel is the development direction and trend of future railway tunnel research. Based on the actual engineering of a railway tunnel, this study developed a safety evaluation model for railway tunnel structures using a fuzzy comprehensive evaluation method and examined a health state evaluation method suitable for most railway tunnel structures. The results showed that the evaluation method comprehensively reflected the impact of various factors, which had strong practicality. The evaluation results were clear, accurate, and consistent with engineering practice. When using the safety factor index to study the stress of a railway tunnel structure, Midas/civil analysis showed that different levels of the surrounding rock structural vault in railway tunnels were in a tensile, control-bearing capacity state. When calculating safety factors, the range of a 60° central angle of a railway tunnel vault was calculated according to the tensile control-bearing capacity. Theoretical formulas of the range of the center angle φ0 of the vault tension zone were derived and then verified by experiments and numerical analysis.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80481209","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

STUDY ON REMOTE INTELLIGENT MONITORING SYSTEM OF SLOPE BASED ON SARMA ALGORITHM AND ARCGIS 基于sarma算法和arcgis的边坡远程智能监测系统研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0002

Jian Gong, Kexin Zhang, Houji Zhang, Honglei Zhang

引用次数: 0

FIELD EXPERIMENTAL STUDY ON EXTERNAL PRESTRESSING REINFORCEMENT OF A 420M PC CONTINUOUS BEAM BRIDGE 420m PC连续梁桥外预应力加固现场试验研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0008

Zhonglin Sun, Quansheng Sun, Jianfei Li, Shengqi Yang

引用次数: 0

CASE STUDY ON THE LARGE DIAMETER PIPE JACKING FOR UTILITY TUNNEL 公用隧道大直径顶管工程实例研究

Stavební obzor - Civil Engineering Journal Pub Date : 2023-04-30 DOI: 10.14311/cej.2023.01.0006

Yongfeng Li, Guoqiang Liu, Jian Liu, Jing Huang, Fang Tian, Fan Liu

{"title":"CASE STUDY ON THE LARGE DIAMETER PIPE JACKING FOR UTILITY TUNNEL","authors":"Yongfeng Li, Guoqiang Liu, Jian Liu, Jing Huang, Fang Tian, Fan Liu","doi":"10.14311/cej.2023.01.0006","DOIUrl":"https://doi.org/10.14311/cej.2023.01.0006","url":null,"abstract":"Pipe jacking have been widely used in utility tunnel constructions as an environment-friendly method in China. This study is focus on the critical technologies used in the pipe jacking for the utility tunnel in Huanggang Mingzhu road. The inner and outer diameter of this utility tunnel are 4m and 4.8m respectively, which is the largest circular pipe jacking project in China at present. This utility tunnel is designed under the urban main road with a heavy traffic, so the control accuracy of pipe jacking construction is required to be high. According to the characteristics of the project and actual construction technical measures, the key construction technologies including pipe jacking equipment, launching of small spacing, slurry circulating, the drag reduction technology, and the control of surface settlement are discussed in this paper. Meanwhile, the jacking force and ground settlement during pipe jacking construction are monitored. The results show that the selected pipe jacking machine has good adaptability to the geological conditions of the project. The actual jacking force is much smaller than the theoretical value, and the two intermediate jacking stations are not activated. In addition, the road surface deformation is -8–5mm during the whole process of pipe jacking construction, which has no impact on surface traffic.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80184317","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