• Title/Summary/Keyword: Construction Key Technology

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SUGGESTING IMPROVEMENT METHODS OF FORM WORK FOR COST REDUCTION IN THE MID-RISE APARTMENT HOUSING

  • Jeongseok Lee;Seunghee Kang;Gunhee Cho;Jeongrak Sohn;Jongdae Bang
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1608-1614
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    • 2009
  • In recent days, the study of urban regeneration has been conducting with purposeful and sincere intent starting out with the residential environment improvement works. Within the range of urban regeneration, the low-cost housing technology means development of totally-integrated housing technology that may be applied to the regeneration project, especially for the rundown areas where infrastructure facilities in the urban zone have been degraded and obsoleted. In line with this, among many and varied methods in order for realization of the low-cost housing as a part of urban regeneration project, this study should like to propose an improvement methods of the key technologies in relation to the construction works by type of work with which construction costs (directing cost) would be reduced. And, in order to elicit the method for element technology that has been developed and improved in the most optimal manner centering on the selected construction work by the type of work, the researcher conducted comparative review of summary of element technologies related to the construction works concerned, characteristics, and construction method thereof. In particular, the researcher investigated the expenses (construction cost and labor cost), constructions (contractibility and productivity), safety, quality of works, and the technical status in environmental aspects, and the researcher also conducted analyses and evaluations thereof.

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A novel prismatic-shaped isolation platform with tunable negative stiffness and enhanced quasi-zero stiffness effect

  • Jing Bian;Xuhong Zhou;Ke Ke;Michael C.H. Yam;Yuhang Wang;Zi Gu;Miaojun Sun
    • Smart Structures and Systems
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    • v.31 no.3
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    • pp.213-227
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    • 2023
  • A passive prismatic-shaped isolation platform (PIP) is proposed to realize enhanced quasi-zero stiffness (QZS) effect. The design concept uses a horizontal spring to produce a tunable negative stiffness and installs oblique springs inside the cells of the prismatic structure to provide a tunable positive stiffness. Therefore, the QZS effect can be achieved by combining the negative stiffness and the positive stiffness. To this aim, firstly, the mathematical modeling and the static analysis are conducted to demonstrate this idea and provide the design basis. Further, with the parametric study and the optimal design of the PIP, the enhanced QZS effect is achieved with widened QZS range and stable property. Moreover, the dynamic analysis is conducted to investigate the vibration isolation performance of the proposed PIP. The analysis results show that the widened QZS property can be achieved with the optimal designed structural parameters, and the proposed PIP has an excellent vibration isolation performance in the ultra-low frequency due to the enlarged QZS range. Compared with the traditional QZS isolator, the PIP shows better performance with a broader isolation frequency range and stable property under the large excitation amplitude.

A STUDY FOR RFID APPLICATION OF CONSTRUCTION MATERIALS

  • Choong-Han Han ;Ki-Bum Ju
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1155-1160
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    • 2009
  • The trend in construction industry, now, lies in improving efficiency and competitive power in construction management and on-the-spot instruction by combining with new IT technology. Above all, it is safe to say that the application of RFID technology can play a pivotal role at this point, but it is not that easy to apply RFID due to the physical, chemical and environmental peculiarities of construction materials. Thus, a study on the standardization of the usable frequency, specifications, protocol, and package administration is required. This study, as part of the study on the standardization, figured out the restrictions by attaching the existing RFID Tag to the construction materials, turned out the prototype of RFID Tag to perform a field test. In result the effective recognition range varies according to the physical and environmental peculiarities of construction materials; and the management efficiency varies as the attaching method and/or applying method. To analyze the management method (media, process etc.) systematically for the existing construction materials; to prepare more various restrictions and its solutions for practical construction spots will be the key for successful RFID implementation.

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An alternative upstream method for the Zhelamuqing tailings impoundment construction of a Copper Mine in China

  • Wei, Zuoan;Chen, Yulong;Yin, Guangzhi;Yang, Yonghao;Shu, Weimin
    • Geomechanics and Engineering
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    • v.19 no.5
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    • pp.383-392
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    • 2019
  • How to safely and economically dispose mining tailings is a challenge to mine operators. This paper presents an alternative upstream method for tailings dam construction, termed as the template construction method (TCM), which has been successfully implemented at Zhelamuqing tailings impoundment since 2004. By the beginning of 2015, the tailings dam wall had reached 95 m in height for the 46 upstream raises, with the total height of the dam including the starter dyke being 128 m. The proposed TCM is relatively simple and cost-effective and provides a good way for constructing rapidly raising tailings dam based on this case.

DEVELOPMENT OF MATERIAL TRACKING SYSTEM USING WIRELESS TECHNOLOGY IN HIGH-RISE BUILDING

  • Jae-Goo Han;Min-Woo Lee;Soon-Wook Kwon;Moon-Young Cho
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1017-1021
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    • 2005
  • There is a need for effective tracking and control of material loading and delivery time especially during the finishing-work phases to eliminate the need for lay-down space on the site. Hence, it is essential to monitor the relevant information regarding material procurement in construction sites, and it is also the key factor for successful site control and the adoption of the Just-in-Time concept for high-rise building construction. The purpose of this study is to test RFID's readability in order to develop a finishing material monitoring system through the application of RFID technology.

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Identification and Molecular Analysis of Ixodid Ticks (Acari: Ixodidae) Infesting Domestic Animals and Tick-Borne Pathogens at the Tarim Basin of Southern Xinjiang, China

  • Zhao, Li;Lv, Jizhou;Li, Fei;Li, Kairui;He, Bo;Zhang, Luyao;Han, Xueqing;Wang, Huiyu;Johnson, Nicholas;Lin, Xiangmei;Wu, Shaoqiang;Liu, Yonghong
    • Parasites, Hosts and Diseases
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    • v.58 no.1
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    • pp.37-46
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    • 2020
  • Livestock husbandry is vital to economy of the Tarim Basin, Xinjiang Autonomous Region, China. However, there have been few surveys of the distribution of ixodid ticks (Acari: Ixodidae) and tick-borne pathogens affecting domestic animals at these locations. In this study, 3,916 adult ixodid ticks infesting domestic animals were collected from 23 sampling sites during 2012-2016. Ticks were identified to species based on morphology, and the identification was confirmed based on mitochondrial 16S and 12S rRNA sequences. Ten tick species belonging to 4 genera were identified, including Rhipicephalus turanicus, Hyalomma anatolicum, Rh. bursa, H. asiaticum asiaticum, and Rh. sanguineus. DNA sequences of Rickettsia spp. (spotted fever group) and Anaplasma spp. were detected in these ticks. Phylogenetic analyses revealed possible existence of undescribed Babesia spp. and Borrelia spp. This study illustrates potential threat to domestic animals and humans from tick-borne pathogens.

Connections between RC beam and square tubed-RC column under axial compression: Experiments

  • Zhou, Xu-Hong;Li, Bin-Yang;Gan, Dan;Liu, Jie-Peng;Chen, Y. Frank
    • Steel and Composite Structures
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    • v.23 no.4
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    • pp.453-464
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    • 2017
  • The square tubed-reinforced concrete (TRC) column is a kind of special concrete-filled steel tube (CFST) columns, in which the outer thin-walled steel tube does not pass through the beam-column joint, so that the longitudinal steel reinforcing bars in the RC beam are continuous through the connection zone. However, there is a possible decrease of the axial bearing capacity at the TRC column to RC beam connection due to the discontinuity of the column tube, which is a concern to engineers. 24 connections and 7 square TRC columns were tested under axial compression. The primary parameters considered in the tests are: (1) connection location (corner, exterior and interior); (2) dimensions of RC beam cross section; (3) RC beam type (with or without horizontal haunches); (4) tube type (with or without stiffening ribs). The test results show that all specimens have relatively high load-carrying capacity and satisfactory ductility. With a proper design, the connections exhibit higher axial resistance and better ductility performance than the TRC column. The feasibility of this type of connections is verified.

Vortex induced vibration and its controlling of long span Cross-Rope Suspension transmission line with tension insulator

  • Tu, Xi;Wu, Ye;Li, Zhengliang;Wang, Zhisong
    • Structural Engineering and Mechanics
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    • v.78 no.1
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    • pp.87-102
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    • 2021
  • Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.

Effects of Different Advance Organizers on Mental Model Construction and Cognitive Load Decrease

  • OH, Sun-A;KIM, Yeun-Soon;JUNG, Eun-Kyung;KIM, Hoi-Soo
    • Educational Technology International
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    • v.10 no.2
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    • pp.145-166
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    • 2009
  • The purpose of this study was to investigate why advance organizers (AO) are effective in promoting comprehension and mental model formation in terms of cognitive load. Two experimental groups: a concept-map AO group and a key-word AO group and one control group were used. This study considered cognitive load in view of Baddeley's working memory model: central executive (CE), phonological loop (PL), and visuo-spatial sketch pad (VSSP). The present experiment directly examined cognitive load using dual task methodology. The results were as follows: central executive (CE) suppression task achievement for the concept map AO group was higher than the key word AO group and control group. Comprehension and mental model construction for the concept map AO group were higher than the other groups. These results indicated that the superiority of concept map AO owing to CE load decrement occurred with comprehension and mental model construction in learning. Thus, the available resources produced by CE load reduction may have been invested for comprehension and mental model construction of learning contents.

Control effect and mechanism investigation on the horizontal flow-isolating plate for PI shaped bridge decks' VIV stability

  • Li, Ke;Qian, Guowei;Ge, Yaojun;Zhao, Lin;Di, Jin
    • Wind and Structures
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    • v.28 no.2
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    • pp.99-110
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    • 2019
  • Vortex-Induced-Vibration (VIV) is one kind of the wind-induced vibrations, which may occur in the construction and operation period of bridges. This phenomenon can bring negative effects to the traffic safety or can cause bridge fatigue damage and should be eliminated or controlled within safe amplitudes.In the current VIV studies, one available mitigation countermeasure, the horizontal flow-isolating plate, shows satisfactory performance particularly in PI shaped bridge deck type. Details of the wind tunnel test are firstly presented to give an overall description of this appendage and its control effect. Then, the computational-fluid-dynamics(CFD) method is introduced to investigate the control mechanism, using two-dimensional Large-Eddy-Simulation to reproduce the VIV process. The Reynolds number of the cases involved in this paper ranges from $1{\times}10^5$ to $3{\times}10^5$, using the width of bridge deck as reference length. A field-filter technique and detailed analysis on wall pressure are used to give an intuitive demonstration of the changes brought by the horizontal flow-isolating plate. Results show that this aerodynamic appendage is equally effective in suppressing vertical and torsional VIV, indicating inspiring application prospect in similar PI shaped bridge decks.