• Title/Summary/Keyword: 토공재

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The Computation of Reinforcement Length of Afforestation Slope (사면녹화 보강토공법의 보강재길이 산정에 관한 연구)

  • Park, Sik-Choon;Nam, Kwang-On;Kim, Jong-Hwan;Lee, Soo-Yang
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1302-1308
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    • 2010
  • This study the change of the safety factor before and after the reinforcement were compared by performing the parameter research based on the limit equilibrium analysis regarding the same cross section after carrying out the safety factor before the reinforcement on the virtual section in order to observe the change of the safety factor of the slop reinforced with the slope planting reinforced earth, and the variation of the safety factor according to the increase of the length of the reinforcement materials and the change of the slope height was analyzed. As the result, the reinforcement effect was insignificant at no more than 0.6 of L/H, the reinforcement length ratio when the reinforcement length was increased, as the increase of the safety factor was slow comparing with the non-reinforced slope. At 3.0m of the slope height, reinforcement on the slope is not necessary, and at 3.0m to 5.0m of the slope height, the inclination was not influencing at no less than 0.6 of L/H. At 5.0m to 9.0m of the slope height, the safety factor was mostly secured on the slope at 0.8 of L/H and the over-reinforced slope appeared at no less than 1.0 of L/H. Also, the safety factor increased as the slope height increases and the slope gets steeper till 0.8 of L/H, but the slope steepness affects more on the increase of the safety factor than the reinforcement material, as the reinforcing force by the reinforcement material became steady.

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A Study on the Technological Improvement of Strut as a Permanent Structure (구조물 겸용 흙막이 스트러트 공법의 개선 연구)

  • Kim, Sun-Kuk;Hong, Won-Kee
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.5
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    • pp.186-193
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    • 2008
  • The SPS, Strut as a Permanent System, method is widely adopted for the main structural member in addition to temporary strut function for the shuttering of excavation work. Although the SPS method has contributed to cost saving, time reduction, enhancement of structural stability, improvement of construction environment and so on at the building construction site, it caused the problems of increase of basement height and additional work for fire protection of steel structure. The increase of basement height caused the increase of shuttering depth and excavation, and the fire protection caused the additional cost as well as the deterioration of construction environment. In order to improve the problems, this paper is to propose a modularized hybrid structural system(HSD). The detail of the system is introduced and the structural performance and constructibility are proved through the experiment and site application.

Applicability of the Pile-Supported Embankment in Korea (성토지지말뚝공법의 국내 적용성 분석)

  • Lee, Il-Wha;Kim, Seung-Sun;Lee, Joo-Gong;Shim, Shung-Kyu;Lee, Su-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.32 no.3
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    • pp.5-13
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    • 2016
  • Stability analysis was conducted to analyze the application of pile-supported embankment to concrete slab track on the soft ground in Korea. Pile efficiency and tension of geosynthetics in accordance with the hight of embankment and the depth of soft soil were carried out by theoretical and numerical methods. Theoretical method predicted more conservatively than the numerical method for all the cases presented herein. The settlement stability is satisfied to allowable criteria of high speed railway in Korea. The pile-supported embankment has great potential for application to soft ground condition.

Evaluation of Drainage Capacity of Precast Concrete-panel Retaining Wall Attached to In-situ Ground Using Numerical Analysis (수치해석을 이용한 원지반 부착식 판넬옹벽의 투수성 평가)

  • Kwon, Youg Kyu;Lee, Jae Won;Hwang, Young-cheol;Ban, Hoki;Lee, Minjae
    • Journal of the Korean Geotechnical Society
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    • v.37 no.3
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    • pp.43-50
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    • 2021
  • On the construction of new roads, the cut slope is inevitable and thus has been widely applied in the mountainous area. Particularly, the retaining wall with the precast concrete panel is often selected for its higher stability and mostly constructed in bottom-up method. However, the bottom-up method results in steeper slope as 1:0.05 before constructiong retaining wall and thus causes poor compaction at backfill which may induce instability during or after the construction. To overcome this problem, precast concrete panel retaining wall was attached in-situ ground (so called top-down). This paper presents the evaluation of drainage capacity of top-down method which has impermeable layer between panel and mortar being used to increase the ability of attachment of the precast concrete panel.

Evaluation of Field Application of Precast Concrete-panel Retaining Wall attached to In-Situ Ground Using Field Test and Numerical Analysis (현장시험 및 수치해석 분석을 통한 원지반 부착식 판넬옹벽의 현장 적용성 평가)

  • Kwon, Yong Kyu;Min, Kyoung-nam;Hwang, Young-cheol;Ban, Hoki;Lee, Minjae
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.99-106
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    • 2020
  • Man-made slope is inevitable to make a new road, which may result in environmental problems as well as collapse of slope. To prevent these problems, various methods such as geogrid reinforced retaining wall, precast concrete-panel retaining wall, and so on, have been introduced and developed. Among these methods, this paper presents the evaluation of field application of precast concrete-panel retaining wall attached to in-situ ground (so called top-down) compared to the conventional construction method of precast concrete-panel retaining wall (so called bottom-up) through the field test and numerical analysis. As a result, the safety factor of both methods in final stage is similar, however, top-down method guarantees the slope stability during the construction compared to bottom-up method.

Research about Application Possibility of Afforestation Reinforced Soil Steep Slope by Nonwoven Geotextile (부직포를 활용한 급경사 녹화보강토공법의 적용 가능성에 관한 연구)

  • Cho, Yong-Seong;Koo, Ho-Bon;Lee, Choon-Kil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4C
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    • pp.239-245
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    • 2006
  • The steep slopes have been increased of new roads, industrial site development and large scale residential development. The preservation administration and steep slope construction are currently investigated by many researchers in Korea. However, concrete retaining wall or reinforced soil (i.e. Block or Pannel) are being applied for the steep slope, which results in the front face form of the structure being limited. This research investigates the method that can make up afforestation environment-friendly circumstances during the construction of steep slope structure. It is considered that steep slope reinforced structure would be possible based on the monitoring results about earth pressure, horizontal displacement and consolidation quality generated during the construction of whole constructing reinforced structure. Also, there no problems in grassy surface, drainage, and deformation in spite of rainy season after construction period and until now. So that the seeding soil layer surface reinforced soil method could be adopt for steep slope reinforced structure and others.

Recycling and Characteristics of Plasma Melting Slag Materials Produced by Different Cooling Methods (플라즈마 용융방식으로 배출된 슬래그의 냉각방식에 따른 재료적 특성 및 재활용)

  • Chung, Juyoung;Bae, Wookeun;Kim, Moonil;Park, Seyong
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.7
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    • pp.25-31
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    • 2010
  • In this study, it was intended to suggest new cooling method that enables to improve the applicability and added value higher than existing slag by applying new cooling method(powder cooling slag) at the time discharging slag, which is produced from the ash melting system that the plasma torch is used for the first time in Korea. It is suggested the applicative direction in the development of future recycling process by discovering its nature of material and applicative possibility as earthwork material. The ashes produced after the sewage sludge discharged from Y city was incinerated by the fluidized bed method and was used as test materials. As result of XRF(X-Ray Flourescence Spectrometry) analysis, main ingredient of sewage sludge ashes was $SiO_2$(32%) besides CaO, $Al_2O_3$, $Fe_2O_3$, and so on. In addition, as result of XRD analysis, traditional diffuse pattern of glass could be found from granulated air-cooled slags, while a minor crystal phase could be observed from powder cooling slag, because the powder on the surface exists in the state not melted. From EDX(Energy Dispersive X-ray Spectroscopy) analysis, it is deemed that powder ingredient has no change before and after it is used as cooling medium, and accordingly it is thought that the powder can be produced as the material where the function is added if used in different shape.

Developing a Computer Model for Forest Road Design (임도설계(林道設計) 자동화(自動化)를 위한 전산(電算)모델의 개발(開發))

  • Chung, Joo Sang;Chung, Woo Dam
    • Journal of Korean Society of Forest Science
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    • v.84 no.3
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    • pp.333-342
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    • 1995
  • A user - oriented computer model to aid designing forest road is developed to release the burden by increasing efficiency of time - consuming and laborious road design works. In this paper, the structures and functions of the model are discussed. The model consists of functional modules : 1)input module to treat survey data and design criteria ; 2)road design module to generate preliminary road layout, horizontal and vertical curvatures and curve widening ; 3)earthwork analysis module to determine the economic mass movement ; 4)report writer module to produce hard copies of engineering drawings for plan views, cross - sections and profiles, earthwork calculation sheets and mass movement diagrams. In addition, the report writer also provides the information on earthwork disturbance along the cut and - fill slopes. The modules are designed to be fully - integrated to enable the users to perform engineering analyses and evaluate design alternatives in a series of road - design procedures.

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Evaluation of Compaction Quality Control applied the Dynamic Cone Penetrometer Test based on IoT (다짐품질관리를 위한 IoT 기반 DCPT 적용 평가)

  • Jisun, Kim;Jinyoung, Kim;Namgyu, Kim;Sungha, Baek;Jinwoo, Cho
    • Journal of the Korean Geosynthetics Society
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    • v.21 no.4
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    • pp.1-12
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    • 2022
  • Generally, the plate load test and the field density test are conducted for compaction quality control in earthwork, and then additional analysis. Recently developed that the DCPT (Dynamic Cone Penetration Test) equipment for smart compaction quality control its the system are able to get location and real-time information about worker history management. The IoT-based the DCPT system improved the time-cost in the field compared traditional test, and the functions recording and storage of the DPI (Dynamic Cone Penetration Index) were automated. This paper describes using these DCPT equipment on in-situ and compared to the standards of the DCPT, and the compaction trend had be confirmed with DPI as the field test data. As a result, the DPI of the final compaction decreased by 1.4 times compared to the initial compaction, confirming the increase in the compaction strength of the subgrade compaction layer 10 to 14 cm deep from the surface. A trend of increasing compaction strength was observed. This showed a tendency to increase the compaction strength of the target DPI proposed by MnDOT and the results of the existing plate load test, but there was a difference in the increase rate. Therefore, additional studies are needed on domestic compaction materials and laboratory conditions for target DPI and correlation studies with the plate load tests. If this is reflected, it is suggested that DCPT will be widely used as smart construction equipment in earthworks.

Material and Behavior Characteristics of Lightweight Embankment for Road Constructed on Soft Ground (연약지반에 시공된 도로용 경량성토체의 재료 및 거동특성)

  • Yea, Geu-Guwen;Lee, Yong-Jae;Kim, Hong-Yeon;Yoon, Gil-Lim;Han, Sang-Hyun
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.2
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    • pp.41-49
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    • 2018
  • The purpose of this study is to fabricate a full scale road embankment using lightweight air foamed soil as a soil material on soft ground and to investigate its material characteristics and behavior in order to promote dredged soil utilization and minimize ground improvement. As a result of the laboratory test of the onsite mixed samples, the total unit weight of the specimens decreased almost linearly until curing 28 days. In particular, the total unit weight after 28 days of curing was reduced to about 81% of the slurry state before curing, which will be useful in the formulation of similar native soil materials in the future. The unconfined compressive strength began to decrease with the 14th day of curing as shown in the previous study. When the cement content is increased, the strength decreases sharply at a small strain change after the occurrence of the maximum compressive strength, and the maximum strength is exhibited in a range of a smaller axial strain than normal range. The settlement at the surface layer of the ground due to the lightweight embankment was about 1 / 2.75 of the soil embankment and was in agreement with the unit weight ratio (1 / 2.7) of the embankment materials. This indicates the cause and effect of the settlement due to the difference in self weight of the embankments. Also, the difference in settlement between soil and lightweight embankment increased with increasing depth. This shows that the difference in the point at which the settlement is terminated is clear. The ground horizontal displacement under the lightweight embankment was about 15~20% smaller than that of the soil embankment and the depth of occurrence was also 4.5~5.0m shallower in the lightweight embankment.