• Title/Summary/Keyword: Road surface

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Analysis of First Flushing Effects and EMCs of Non-point Pollutants from Impervious Area during Rainfall (강우시 불투수성 지역의 비점오염물질 EMCs 산정 및 초기세척효과 분석)

  • Ahn, Tae-Woong;Kim, Tae-Hoon;Oh, Jong-Min
    • Korean Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.459-473
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    • 2012
  • This study evaluated the rainfall-runoff characteristics of Non-point Pollution Source (NPS) of the impervious area through on-site monitoring. In this study, trend analysis was performed by various runoff analysis method of non-point pollution source. The characteristics of rainfall at impervious area appeared to be influenced by rainfall strength. It is judged that the measure is required to be prepared against that now that concentration difference of non-point pollution source appeared to be big by precedent number of days of no rainfall. However, it appeared that Rainfall Sustaining Time (RST) has nothing to do with effluent concentration of non-point pollution source, however, the rising tendency that effluent concentration did not appear because the tendency that concentration of non-point pollution source reduces more than 50% within initial 60 min due to first flushing effects and rainfall sustaining time is long. If looking into the outflow tendency of non-point pollution source at the impervious area, it showed the tendency that the concentration lowers gradually as time goes by after initial concentration appeared very high. However, it could be recognized that the concentration of non-point pollution source appeared to be high as the pollutants integrated on the surface of the road during dry season. The Event Mean Concentrations (EMCs) in impervious area were ranged $9.2{\sim}199.3mg{\cdot}L^{-1}$ for TSS, $8.1{\sim}24.2mg{\cdot}L^{-1}$ for $COD_{Mn}$, $0.070{\sim}1.860mg{\cdot}L^{-1}$ for T-N. Based on such runoff characteristics of non-point pollution source, it is judged that it would be desirable to process initial rain efficiently as the measure against initial rain phenomenon at the impervious area.

A Study on the Development of Experiential Nature Education Program in the Urban Forest Park - A Case Study of Yeongheung Park in Suwon - (도시 산림공원의 체험형 자연교육 프로그램 개발 연구 - 수원 영흥공원을 대상으로 -)

  • Chang, Ye-Na;Kim, Sung-Hee;Han, Bong-Ho;Choi, Jin-Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.6
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    • pp.12-23
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    • 2019
  • The purpose of this study was to develop and study an experiential natural education program that could emphasize the importance of the natural environment by providing natural experience opportunities using the natural resources of the urban forest parks using Youngheung Park in Suwon, Gyeonggi Province as a target site. The research target was limited to Suwon Yeongheung Park, which had the potential to become a place for education, where urban forest conservation and sustainable use already coexist. The natural education resources derived by surveying and analyzing the basic environment and the ecology of plants and animals in Suwon Yeongheung Park were organized to establish program goals, directions, and themes. Suwon Yeongheung Park is a water-rich forest that forms an ecological system of wetlands, including rice paddies, muknon wetlands, and dungbun, near a valley area. The U-shaped walkway was smoothly formed along the ridge and includes Doran-gil, which is among the Palochrome Road, designated by the city of Suwon. The soil is acidic, with a pH 4.40, due to urban pollution and acid rain, and is not good for plant growth. Most of the artificial forests, natural forests, and arable land were found using land use and extant life surveys. Old trees were distributed in artificial forests, the oak clusters in natural forests, and the fields and darrinones were distributed in the arable areas. As the forest vegetation declined, the cedar forest was underway, and the cedar trees and red bean pear trees were cultivated due to their adaptability to the urban environment. There are 13 large of 180 sacks, one being 109 centimeters in diameter, the largest silvery tree, and 105 oak trees, provide food and shelter for animals. Six species of waterfowl that used the 22 kinds of forest wetlands, while four species of amphibians and two species of reptiles reside in the wetlands. Natural Monument No. 327, Mauryuk, Class II Endangered Wildlife, was also observed in the wetlands. Eight other species of surface dragonflies and three species of butterflies were observed. By systemizing the resources, members, and characteristics of the forest ecosystems in Suwon Yeongheung Park based on five criteria, the program for a hands-on natural education was presented with the aim of understanding the urban forest ecosystem in Suwon Yeongheung Park, having an affinity with the city, and recognizing its relationship with the community and society. However, further research is needed as there are limitations of research on programs characterized by different ages and classes.

Development of Evaluation Method for Jointed Concrete Pavement with FWD and Finite Element Analysis (FWD와 유한요소해석을 이용한 줄눈콘크리트포장 평가법 개발)

  • Yun, Kyong-Ku;Lee, Joo-Hyung;Choi, Seong-Yong
    • International Journal of Highway Engineering
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    • v.1 no.1
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    • pp.107-119
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    • 1999
  • The joints in the jointed concrete pavement provide a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random cracks cause more serious distresses and result in structural or functional failure of pavement system. However, joints nay cause distresses due to its inherent weakness in structural integrity. Thus, the evaluation at joint is very important. and the joint-related distresses should be evaluated reasonably for economic rehabilitation. The purpose of this paper was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis program, ILLI-SLAB, and nondestructive testing device. FWD. To develop an evaluation system for JCP, a sensitivity analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. An evaluation charts were made for jointed concrete pavement by adopting the field FWD data. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP are 300pci. 500,000 lb/in. respectively. Using these variables and FWD test, a charts of load transfer ratio versus surface deflection at joints were made in order to evaluate the performance of JCP. Practically, Chungbu highway was evaluated by these evaluation charts and FWD field data for jointed concrete pavement. For Chungbu highway, only one joint showed smaller value than limiting criterion of the modulus of dowel/concrete interaction(G). The rest joints showed larger values than limiting criteria of the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G).

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Evaluation of Construction Operation and Design Properties of CLSM for Corrugated Pipe in Underground (파형강관을 이용한 지하매설물용 뒤채움재 설계 및 시공성 평가)

  • Lee Kwan-Ho;Park Jae-Heon
    • International Journal of Highway Engineering
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    • v.8 no.2 s.28
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    • pp.63-74
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    • 2006
  • During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

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Case Study on the Space Characteristics Focused on the Dang and Oreum of the Seashore.Inland Villages in Jeju Island (당(堂)과 오름을 중심으로 한 제주도 해안.중산간마을의 공간 특성 사례연구)

  • Choi, Jai-Ung;Kim, Dong-Yeob;Jo, Lock-Whan;Kim, Mi-Heui;Ahn, Ok-Sun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.2
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    • pp.101-109
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    • 2012
  • Traditional village forests in Jeju Island represent unique cultural landscape with a history of more than several hundred years as a national cultural asset in Korea. In this paper, the characteristics and meaning of traditional village forests in Jeju Island was compared with the Dangsan and Bibo forests at inland. There are 368 Oreums, parasitic volcano, and 391 shrines of Dang(Divine place) in Jeju. Life, culture and tradition of rural villages are all connected with the Dang and Oreum in Jeju. It has been found from this study that the village in Jeju were established as a cultural landscape on the surface of natural landscape. The features of traditional villages focused on the Dang and Oreum in Jeju Island were similar to the Dangsan and Bibo forestsat inland villages. The Oreum represents mountain and the Pojedan forest is newly found in Sangmyung-ri. The seashore areas are covered by vaocanic rocks in Jeju and large scale windbreaks are hardly found. The stone tower at Sinheung-ri built for blocking sand movement represents Bibo forest. The special attribute of the Dang in Jeju is that it is close to real life and believers are still remain. In 2009, the Jeju Chilmeoridang Yeongdeunggut ritual was nominated as an Intangible Cultural Heritage of Humanity by UNESCO. The shrine of Dang, however, has been degraded fast by construction of seashore road and Jeju Olle trail path. As for the world cultural heritage discussed at international conferences, it is important that there is sustainability on the right to enjoy cultural heritage. Integrated efforts from local residents, local governments and national government are needed to set up a management scheme for the Dang culture. Rural villages in Jeju with the Dang and Oreum are expected to get an international attention as to have traditional cultural landscapes of Korea.