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Number of results: 9
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Abstract

The technology of single bore multiple anchor is well known and mainly used as a method of providing support for retaining walls of deep excavations in weak soils. Multiple fixed lengths in a single borehole is a major difference to conventional anchors. The purpose of it and the most important facts affecting bearing capacity are presented. Due to the reduction of progressive debonding higher bearing capacities can be achieved and the impact of soil consolidation is decreased. Unique properties of this technology potentially reduce construction costs and increase the reliability and safety of the structure. Single Bore Multiple Anchors in most cases are prestressed by synchronised hydraulic jacks to provide that every anchor unit transfers the same load. The purpose of this paper is to present the results of investigation and suitability tests, which took place at the site of Zlote Tarasy Shopping Centre in Warsaw. The carried out research reveals that prestressing of one fixed anchor causes a decrease in lock-off load of the second fixed anchor, regardless of the order of prestressing. Measured values presents range from 6% to 14%. Results indicate mutual influence between loads of fixed anchors from the separate prestressing.
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Authors and Affiliations

Jan Kalicki
1
ORCID: ORCID
Monika Mitew-Czajewska
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 0-637 Warsaw, Poland
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Abstract

The article applies the concept of anchoring, defined as the process of searching for footholds and points of reference which allows individuals to acquire socio-psychological stability and security and function effectively in a new environment, to explore complex, multidimensional and flexible adaptation and settlement processes among migrants from Ukraine in Poland. Based on 40 in-depth interviews and questionnaires with migrants resident in Warsaw and its vicinity, we argue that the traditional catego-ries employed for analysing migrants’ adaptation and settlement such as ‘integration’ or ‘assimilation’ are not always adequate to capture the way of functioning and experience of contemporary Ukrainian migrants. Rather than traditional categories, we propose to apply the concept of anchoring which ena-bles us to capture Ukrainians’ ‘fluid’ migration, drifting lives and complex identities as well as mecha-nisms of settling down in terms of searching for relative stability rather than putting down roots. The paper discusses the ambiguous position of Ukrainian migrants in Poland constructed as neither-strangers nor the same, gives insight into their drifting lives and illuminates ways of coping with tem-porariness and establishing anchors to provide a sense of stability and security. This approach, linking identity, security and incorporation, emphasises, on the one hand, the psychological and emotional as-pects of establishing new footholds and, on the other hand, tangible anchors and structural constraints. Its added value lies in the fact that it allows for the complexity, simultaneity and changeability of an-choring and the reverse processes of un-anchoring to be included.

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Authors and Affiliations

Aleksandra Grzymała-Kazłowska
Anita Brzozowska
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Abstract

The problem of setting out in civil engineering applications has been addressed in the literature for a long time. However, technological development has provided researchers with an opportunity of having other procedures in line with modern techniques in surveying sciences. One of the most important procedures in erecting steel structures, bridges, and precast columns of a building is the accurate placement of the anchorage system in concrete. The traditional method for staking out anchor bolts relies on sight rails, string lines, and tape measure. The precision of this art depends not only on the accuracy of observed offset distances during layout operations but also on the centerline of the anchoring template itself. Nowadays, the process of designing structures is executed using software that can perform a digital plan in CAD environment, where the coordinates of each anchor bolt can be defined. This research presents an accurate approach of positioning anchor bolts based on the second problem in surveying and total station. Error analysis and field application are described to evaluate the performance of the proposed method. However, the results indicate that the developed technique increases productivity, reduces the cost, and improves the positional accuracy.

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Authors and Affiliations

M. Habib
A. Malkawi
M. Awwad
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Abstract

Prestressed anchor cables are active reinforcement to improve slope stability. However, the anchoring is not a permanent guarantee of stability, and the slope retains a potential risk of instability. From the perspective of the internal force of anchor cables, a new early warning method for the safety of the slope is provided, and a slope analysis model is established. With the increase in the strength reduction factor, the internal force increment curves of anchor cables under different prestresses are obtained. The point corresponding to strength reduction factors λ1 and λ2 represents a warning point. Key conclusions are drawn as follows: (1) The internal force of an anchor cable can be used to judge the stability of the slope strengthened by a prestressed anchor cable. (2) A warning index based on the internal force increment ratio of anchor cables is established. (3) The internal force increment ratio of anchor cables eliminates the influence of the initial prestress and is convenient for engineering applications.
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Authors and Affiliations

Jincai Feng
Jiaxin Chen
Jian Li
Yu Zhang
ORCID: ORCID
Jianhua Guo
Hongyong Qiu
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Abstract

The roadway surrounding rock is often subjected to severe damage under dynamic loading at greater mining depths. To study the dynamic response of prestressed anchors, the damage characteristics of anchor solids with different prestresses and number of impacts under dynamic and static loads were investigated by improving the Hopkinson bar equipment. The effect of prestress on stress wave transmission was obtained, and the laws and reasons for axial force loss under static and dynamic loads were analyzed. The damage characteristics of anchor solids were determined experimentally. The results show that with an increase in prestress from 15 to 30 MPa, the peak value of the stress wave gradually increases and the decay rate gradually decreases. Shear damage occurred at the impact end of the specimen, combined tension and shear damage occurred at the free end, and fracture occurred in the middle. With an increase in the number of impacts, the damage to the anchor solid specimens gradually increased, and the prestressing force gradually decreased. After impact, the axial force of the various prestressed anchor solid specimens gradually increased; however, the anchor bar with a 17 MPa prestressing force had the slowest rate of axial force loss during impact, withstanding a greater number of impacts. In on-site applications, after three explosions, the displacement on both sides of the tunnel supported by 17 MPa prestressed anchor rods could be controlled within 0.3 m, with an average displacement of 206, 240, and 283 mm, respectively, increasing by 16.5% and 17.9%. This study, based on theoretical analysis and laboratory research combined with field application provides guidance for the anchor support of a dynamic loading tunnel.
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Authors and Affiliations

Zhiqiang Yin
1
ORCID: ORCID
Chao Wang
1
ORCID: ORCID
Zhiyu Chen
2
ORCID: ORCID
Youxun Cao
3
ORCID: ORCID
Tao Yang
3
ORCID: ORCID
Deren Chen
4
ORCID: ORCID
Dengke Wang
4
ORCID: ORCID

  1. Anhui University of Science and Technology, School of Mining Engineering, Anhui ProvinceCoal Mine Safety Mining Equipment Manufacturing Innovat ion Center, Huainan 232001,China
  2. Industrial and Energy Administrat ion of Xishui County, Zunyi 564699, China
  3. Great Wall No.6 Mining Co. LTD, Etuokeqianqi 016200, China
  4. Shandong Huakun Geological Engineering Co. LTD, Taian 271413, China
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Abstract

The multi-stimulus test with hidden reference and anchors (MUSHRA) is commonly used for subjective quality assessment of audio systems. Despite its wide acceptance in scientific and industrial sectors, the method is not free from bias. One possible source of bias in the MUSHRA method may be attributed to a graphical design of its user interface. This paper examines the hypothesis that replacement of the standard multi-slider layout with a single-slider version could reduce a stimulus spacing bias observed in the MUSHRA test. Contrary to the expectation, the aforementioned modification did not reduce the bias. This outcome formally supports the validity of using multiple sliders in the MUSHRA graphical interface.
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Authors and Affiliations

Sławomir Zieliński
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Abstract

In knowledge based economy, which actually reflects the knowledge oriented modern society, career development of its members becomes the key factor, same as investing in career “portfolio”. In the article a career construct is invoked as an individual’s property considering individual career choices, individual career development planning and monitoring strategies. When addressing career related matter, one cannot overlook the issue of subjective meaning given to a career in the context of satisfactory outcome and success achievement experienced by the subject. Cognitively interesting issue addressed by the author are the results of research into evaluation of one’s own chances to succeed from the perspective of university students who are in the transition period from academic education to entering a job market.

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Authors and Affiliations

Agnieszka Cybal-Michalska
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Abstract

Localization is one of the oldest mathematical and technical problems that have been at the forefront of research and development for decades. In a wireless sensor network (WSN), nodes are not able to recognize their position. To solve this problem, studies have been done on algorithms to achieve accurate estimation of nodes in WSNs. In this paper, we present an improvement of a localization algorithm namely Gaussian mixture semi-definite programming (GM-SDP-2). GMSDP is based on the received signal strength (RSS) to achieve a maximum likelihood location estimator. The improvement lies in the placement of anchors through the Fuzzy C-Means clustering method where the cluster centers represent the anchors’ positions. The simulation of the algorithm is done in Matlab and is based on two evaluation metrics, namely normalized root-mean-squared error (RMSE) and cumulative distribution function (CDF). Simulation results show that our improved algorithm achieves better performance compared to those using a predetermined placement of anchors.
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Authors and Affiliations

Sidi Mohammed Hadj Irid
1
Mourad Hadjila
1
Mohammed Hicham Hachemi
2
Sihem Souiki
3
Reda Mosteghanemi
1
Chaima Mostefai
1

  1. Dept. of Telecommunications, Faculty of Technology, University of Abou Bekr Belkaid, Tlemcen, Algeria
  2. Dept. of Electronics, Faculty of Electrical Engineering, University of Science and Technology of Oran - Mohamed Boudiaf (USTO-MB), Oran, Algeria
  3. Dept. of Telecom, Faculty of Technology, University of Belhadj Bouchaib, Ain Temouchent, Algeria
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Abstract

The shear lag effect of the steel box girder section in a self-anchored suspension bridge was investigated in this study. Finite element analysis software Midas Civil was used to discretize the girder under analysis into space plate elements and establish a plate element model. The law of shear lag in the longitudinal direction of the girder in the construction and completion stages was determined accordingly. The shear lag coefficient appears to change suddenly near the side support, middle support, side cable anchorage area, and near the bridge tower support of the steel box girder under the imposed load. The most severe shear lag effect is located near the side support and near the side cable anchorage area. Steel box girder sections are simulated before and after system conversion to analyze the shear lag coefficient in the bridge construction stage. The results show that the shear lag coefficient markedly differs before versus after system conversion due to the different stress mechanisms. The finite element analysis results were validated by comparison with the results of an analysis via analogous rod method.
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Authors and Affiliations

Yanfeng Li
1
ORCID: ORCID
Ying He
2
Longsheng Bao
1
ORCID: ORCID
Baoyun Sun
1
ORCID: ORCID
Qinghe Wang
1
ORCID: ORCID

  1. Prof., PhD., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
  2. DSc., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China

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