• Title/Summary/Keyword: $c_1$-construction

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Development and Application of Tunnel Design Automation Technology Using 3D Spatial Information : BIM-Based Design for Namhae Seomyeon - Yeosu Shindeok National Highway Construction (3D 공간정보를 활용한 터널 설계 자동화 기술 개발 및 적용 사례 : 남해 서면-여수 신덕 국도 건설공사 BIM기반 설계를 중심으로)

  • Eunji Jo;Woojin Kim;Kwangyeom Kim;Jaeho Jung;Sanghyuk Bang
    • Tunnel and Underground Space
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    • v.33 no.4
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    • pp.209-227
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    • 2023
  • The government continues to announce measures to revitalize smart construction technology based on BIM for productivity innovation in the construction industry. In the design phase, the goal is design automation and optimization by converging BIM Data and other advanced technologies. Accordingly, in the basic design of the Namhae Seomyeon-Yeosu Sindeok National Road Construction Project, a domestic undersea tunnel project, BIM-based design was carried out by developing tunnel design automation technology using 3D spatial information according to the tunnel design process. In order to derive the optimal alignment, more than 10,000 alignment cases were generated in 36hr using the generative design technique and a quantitative evaluation of the objective functions defined by the designer was performed. AI-based ground classification and 3D Geo Model were established to evaluate the economic feasibility and stability of the optimal alignment. AI-based ground classification has improved its precision by performing about 30 types of ground classification per borehole, and in the case of the 3D Geo Model, its utilization can be expected in that it can accumulate ground data added during construction. In the case of 3D blasting design, the optimal charge weight was derived in 5 minutes by reviewing all security objects on the project range on Dynamo, and the design result was visualized in 3D space for intuitive and convenient construction management so that it could be used directly during construction.

A Study on the Workability Estimation of Water-Soluble Rubberized Asphalt Waterproofing of Spray Type - Focus on the Material Condition - (수용성 뿜칠형 고무 아스팔트 방수재의 시공성 평가에 관한 연구 - 재료 조건을 중심으로 -)

  • Oh, Sang-Keun;Bae, Kee-Sun;Lee, Won-Hun;Kwak, Kyu-Sung;Choi, Eun-Su
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.2
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    • pp.141-148
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    • 2003
  • This study deals with the estimation of material properties according to the construction condition for water-soluble rubberized asphalt waterproofing material of spray type. In this study, the waterproofing material property by the spray construction method is suggested by means of estimation its tensile performance and temperature dependency according to mix proportion ratio(4:1, 8:1), referenced viscosity and solid content (A:360cps, 76%, B:580cps, 79%, C:490cps, 70%), spray angle($30^{\circ}$, $45^{\circ}$, $60^{\circ}$), and spray distance(30cm, 50cm, 70cm). The result of testing are as follows. (1) The mix proportion ratio of principal agent and hardener is 4:1. (2) The viscosity referenced and solid content are 490cps and 70%. (3) The spray angle referenced is $45.^{\circ}$ (4) The distance referenced from concrete surface to spray gun is 40~50cm.

Effects of Forest Road Construction on Stream Water Qualities(I) - The Variation of Suspended Sediment by Forest Road Construction - (임도개설(林道開設)이 계류수질(溪流水質)에 미치는 영향(影響)(I) - 임도개설(林道開設)에 따른 부유토사량(浮遊土砂量)의 변화(變化) -)

  • Chun, Kun-Woo;Kim, Min-Sik;Ezaki, Tsugio
    • Journal of Korean Society of Forest Science
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    • v.85 no.2
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    • pp.280-287
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    • 1996
  • This study was carried out to investigate the export rate of suspended sediment by different precipitation intensity after forest road construction for torrential streams on three different watersheds with various forest road density(Watershed A : 6.67m/ha, Watershed B : 5.52m/ha, and Watershed C : control) in the Experimental Forest of Kangwon National University. The results were as follows. 1. Closely related to the the amount of rainfall in both 1994 and 1995, the average streanfkiw rate was less than $0.25{\times}10^4m^3/day$ during May and June and $5.0{\times}10^4m^3/day$ during July and August. More than $25{\times}10^4m^3/day$ of streanflow rate was occurred twice in 1994 and seven times in 1995. 2. The amount of suspended sediment in three watersheds was less than standard of drinking water(25mg/l) before road construction with daily rainfall of 74mm, 92mm, and 120mm in 1994, also after road construction with daily rainfall of 21mm and 47mm in 1995. But, under the 192mm of daily rainfall, Watershed C did not show the difference in the amount of suspended sediment, however, Watershed A and B produced 1,525mg/l and 775mg/l, respectively, which is 61 and 31 fold of stabdard of drinking water, and construction to export for 35 hours after rainfall. 3. The maximum amount of suspended sediment was less than the standard of drinking water with light rainfall before and after road construction. Under the 192mm of daily rainfall, the maximum amounts of suspended sediment in Watershed A and B were 13,150mg/l and 2,690mg/l, of 526 and 108 fold of standard of drinking water, respectively, showing obvious water pollution by sedimentation. Results of the study indicated that the forest road construction had great influence on the sedimentation, and getting increased by higher road density and heavier rainfall. Therefore such practices as vegetation covering and soil erosion control facility should be established accompanying with forest road construction to prevent from sedimentation.

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Activity and Safety Recognition using Smart Work Shoes for Construction Worksite

  • Wang, Changwon;Kim, Young;Lee, Seung Hyun;Sung, Nak-Jun;Min, Se Dong;Choi, Min-Hyung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.654-670
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    • 2020
  • Workers at construction sites are easily exposed to many dangers and accidents involving falls, tripping, and missteps on stairs. However, researches on construction site monitoring system to prevent work-related injuries are still insufficient. The purpose of this study was to develop a wearable textile pressure insole sensor and examine its effectiveness in managing the real-time safety of construction workers. The sensor was designed based on the principles of parallel capacitance measurement using conductive textile and the monitoring system was developed by C# language. Three separate experiments were carried out for performance evaluation of the proposed sensor: (1) varying the distance between two capacitance plates to examine changes in capacitance charges, (2) repeatedly applying 1 N of pressure for 5,000 times to evaluate consistency, and (3) gradually increasing force by 1 N (from 1 N to 46 N) to test the linearity of the sensor value. Five subjects participated in our pilot test, which examined whether ascending and descending the stairs can be distinguished by our sensor and by weka assessment tool using k-NN algorithm. The 10-fold cross-validation method was used for analysis and the results of accuracy in identifying stair ascending and descending were 87.2% and 90.9%, respectively. By applying our sensor, the type of activity, weight-shifting patterns for balance control, and plantar pressure distribution for postural changes of the construction workers can be detected. The results of this study can be the basis for future sensor-based monitoring device development studies and fall prediction researches for construction workers.

Synthesizing and Assessing Fire-Resistant Geopolymer from Rejected Fly Ash

  • An, Eung-Mo;Cho, Young-Hoon;Chon, Chul-Min;Lee, Dong-Gyu;Lee, Sujeong
    • Journal of the Korean Ceramic Society
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    • v.52 no.4
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    • pp.253-263
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    • 2015
  • Ordinary Portland cement is a widely favored construction material because of its good strength and durability and its reasonable price; however, spalling behaviour during fire exposure can be a serious risk that can lead to strength degradation or collapse of a building. Geopolymers, which can be synthesized by mixing aluminosilicate source materials such as metakaolin and fly ash, and alkali activators, are resistant to fire. Because the chemical composition of geopolymers controls the properties of the geopolyers, geopolymers with various Si:Al ratios were synthesized and evaluated as fire resistant construction materials. Rejected fly ash generated from a power plant was quantitatively analyzed and mixed with alkali activators to produce geopolymers having Si:Al ratios of 1.5, 2.0, and 3.5. Compressive strength of the geopolymers was measured at 28 days before and after heating at $900^{\circ}C$. Geopolymers having an Si:Al ratio of 1.5 presented the best fire resistance, with a 44% increase of strength from 29 MPa to 41 MPa after heating. This material also showed the least expansion-shrinkage characteristics. Geopolymer mortar developed no spalling and presented more than a 2 h fire resistance rating at $1,050^{\circ}C$ during the fire testing, with a cold side temperature of $74^{\circ}C$. Geopolymers have high potential as a fire resistant construction material in terms of their increased strength after exposure to fire.

Effect of Anchorage on Strength of Precast R/C Beam-Column Joints

  • Kim, Kwangyeon
    • Architectural research
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    • v.2 no.1
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    • pp.55-60
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    • 2000
  • Recently, there is a great demand for precast reinforced concrete (RC) construction methods on the purpose of simplicity in construction. Nishimatsu Construction Company has developed a construction method with precast reinforced concrete members in medium-rise building. In this construction method, how to joint precast members, especially the anchorage of the main bar of beam, is important problem. In this study, the structural performance of exterior joints with precast members was investigated. The parameters of the test specimens are anchorage type of the main bar of beam (U-shape anchorage or anchorage plate) and the ratio of the column axial force to the column strength. Specimens J-3 and J-4 used U-shape anchorage and the ratio of the column axial force of specimen J-4 was higher. On the other hand, specimens J-5 and J-6 used anchorage plate, and the anchorage lengths are 15d and 18d, respectively. Experimental results are summarized as follows; 1) For the joints with beam flexural failure mode, it was found that the maximum strength of specimen with anchorage plate is equal to or larger than that of specimen with conventional U-shaped anchorage if the anchorage length of more than 15d would be ensured, 2) Each specimen shows stable hysteretic curves and there were no notable effects on the hysteretic characteristics and the maximum strength caused by the anchorage method of beam main bar and the difference of column axial stress level.

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Sensory Evaluation of Quality and Constructability of Cement Mortar for Tile Direct Setting Method Depending on Mix Proportions (타일 떠붙임 시멘트 모르타르의 배합비 변화에 따른 품질 특성 및 시공성에 대한 관능 평가)

  • Hwang, Yin-Seong;Ki, Tae-Kyoung;Han, Dong-Yeop;Noh, Sang-Kyun
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.1
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    • pp.11-19
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    • 2021
  • The aim of the research is providing a fundamental data on quality and constructability of direct tile setting method depending on various cement to sand ratio for tiling dry cement mortar. A large number of tile setting failures reported is related with the cement mortar and its construction for tiling. Because of different materials of tiles, the properties of tiling dry cement mortar, an adhesive for tiling, can influence on quality and constructability of tiling differently. Practically, the easiest way of controlling the properties of the tiling dry cement mortar is to control the proportion of cement and sand. Hence, in this research, sand to cement ratio (S/C) was controlled. Since there is no standarized method on evaluating performance of dry cement mortar for tiling, a several sensory evaluation methods were suggested and executed. According to the experiments conducted in this research, the adhesive performance of cement mortar for tiles can be different depending on the sides such as tile and substrate. Additionally, depending on S/C, finishability, initial adhesive performance, and tile shifting resistance can be changed for ceramic tile. Therefore, under the conditions of this research, about 5 of S/C can be recommended for appropriate performace of tiling dry cement mortar.

Characterization of NOx Reduction on Filter Bag Support System at Low Temperature using Powder Type MnOx and V2O2/TiO2 Catalysts (분말형 MnOx와 V2O2/TiO2 촉매를 이용한 저온영역의 백필터 공정에서 질소산화물 제거 특성)

  • Kim, Byung-Hwan;Kim, Jeong-Heon;Kang, Pil-Sun;Yoo, Seung-Kwan
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.1
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    • pp.1-9
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    • 2010
  • In this study, the selective catalytic reduction of $NO_x$ with ammonia was carried out in a filter bag support reactor. The experiments were performed by powder type $MnO_x$ and $V_2O_5$/$TiO_2$ catalyst at low temperature between 130 and $250^{\circ}C$. Also, the effect of $SO_2$ and $H_2O$ on the NO conversion was investigated under our test conditions. The powder type catalysts were analyzed by X-ray photoelectron spectrum (XPS), X-ray diffraction(XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). It was observed that NO removal efficiency of the powder type $V_2O_5$/$TiO_2$ catalyst was 85% at low temperature($200^{\circ}C$) under presence of oxygen and that of $MnO_x$ was 50% at the same condition. The powder type $V_2O_5$/$TiO_2$ catalyst, in conclusion, was found to be available for SCR reaction in a filter bag support system.

Thermal Environment Characteristics of Permeable Block Pavements for Landscape Construction (조경용 투수성 블록 포장의 열환경 특성)

  • Han Seung-Ho;Ryu Nam-Hyong;Kang Jin-Hyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.2 s.115
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    • pp.18-25
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    • 2006
  • This study aims to measure and to analyze the thermal environment characteristics of the various permeable pavement materials such as grass pavement (GREEN BLOCK PARK), stone and grass pavement (GREEN BLOCK STEP), stone pavement (GREEN BLOCK MOSAIC) and wood pavement (WOOD BLOCK) under the summer outdoor environment. The thermal environment characteristics measured in the study includes the changes of surface temperature during the day, changes of the temperature on each pavement layer, and long and short wave radiation of each pavement surface. The experimental condition is based on the data on the hottest temperature (August 5, 2005, $34.0^{\circ}C$) of the you. Some of main findings are: 1) The heat environment was worse on the wood pavements than on the stone pavement. This is mainly due to the low albedo of the wood pavements (0.37) while the albedo value of stone pavements is 0.41. Small heat capacity of the wood pavements also contributes to this difference. 2) The heat environment was worse on the stone pavements than on the turf pavements. This was mainly due to the evapotranspiration of the plant growth layer of the turf pavements. 3) The peak surface temperature was the highest on the wood pavements ($56.1^{\circ}C$). The peak surface temperatures on the stone pavements, the stone-grass pavements and the grass pavements were $43.1^{\circ}C,\;40.1^{\circ}C\;and\;37.9^{\circ}C$, respectively. 4) To improve the thermal environments in the urban area, it is recommended to raise the albedo of the pavements by brightening the surface color of the pavement materials. Further studies on the pavement materials and the construction methods which can enhance the continuous evapotranspiration from the pavements surface are needed.

A Study on Shape and Construction of Sleeve Shown in Western Costume

  • Park, Jin-Hee;Lee, Hye-Young
    • International Journal of Costume and Fashion
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    • v.3
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    • pp.89-105
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    • 2003
  • The purpose of this study is to classify sleeves that play an important role in upper-garment designs and that can be presented in diverse shapes by meaningful era. Also, characteristics and trends of sleeves are analyzed to provide a basis for development of design on modem woman's dress. To examine formation and construction of sleeves, literature review and empirical examination were conducted, focusing on patterns of woman's dress presented in literature. This study is to concentrate on the period, the Renaissance to the 19C. In this study, characteristics of sleeves are analyzed by each era according to its shapes and construction. By analyzing the shape of sleeves and the characteristics of the construction of sleeves, the following conclusions had been reached. 1) Sleeves evolved from single, draped garments into dimensional shapes which were manipulated to reflect the changing trends. Considering the comfort and ease of movement have always been very important in clothing design and the construction of sleeves throughout the ages has consistently been able to provide the comfort that wearer demanded. 2) Shape of sleeves varies a little in each period, but recurring trends in fashion led to similar design in sleeves being repeated. Also, instead of a dramatic change in the construction of sleeves, each period had its own unique technique to add freshness by using a variety of ornamentation.