• Title/Summary/Keyword: urban rock

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Process, Governance, and Performance of Creative-City Related Policies of Suncheon City, Korea (순천시 창조도시 관련정책의 추진과정, 거버넌스, 성과)

  • Lee, Jeong-Rock
    • Journal of the Economic Geographical Society of Korea
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    • v.19 no.4
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    • pp.660-676
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    • 2016
  • The Suncheon city has new city image and brand as eco & garden city in national wide. This paper reviews the process, governance, and performance of creative-city related policy in Suncheon city, Korea. The new city image and brand, eco & garden city, were as a result of the related urban policies and its efforts to reserve and utilize the Suncheon Bay Wetland such as the establishment of Green Suncheon 21, the Reed Festival of Suncheon Bay, the ecological park creation projects for Suncheon Bay Wetland, the ICEXPO 2013, and the Suncheon Bay National Garden since 1995. The Dongsa Research Institute has been played very import roles in the process of civic movement for Suncheon Bay Wetland reservation. After holding the ICEXPO 2013, the Suncheon city has achieved various performances such as new city image and brand, the Suncheon Bay National Garden, social and physical infrastructure to pursue future creative-city related policies.

Analytical Study on the Appropriateness of Design Formula and Possibility of Improving Bearing Capacity of Bored Pile (매입말뚝의 설계식 적정성 및 지지력 상향 가능성 분석 연구)

  • Park, Jong-Bae;Lee, Bum-Sik;Park, Yong-Boo
    • Land and Housing Review
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    • v.6 no.3
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    • pp.139-145
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    • 2015
  • To improve the pile design efficiency(design bearing capacity/the strength of materials) from 70 percent(160tonf) to 80 percent(190tonf), this paper analysed the existing pile loading test data and performed the precise dynamic loading test and Bi-directional loading test for the first time in Korea. Analysis result of the existing dynamic loading test data by Davisson method showed that bearing capacity of piles penetrated at weathered rock stratum(N=50/15) exceeded 190tonf. But the analysis result by CAPWAP method showed that piles less than the target bearing capacity were 40% due to the lack of impact energy. To get the target bearing capacity from the dynamic loading test, using the hammer over 6tonf to trigger the enough impact energy is necessary. Allowable bearing capacty of Bi-directional static loading test by Davisson method was 260.0~335tonf(ave. 285.3tonf) and exceeded overwhelmingly the target capacity. And this exceeded the bearing capacity of precise dynamic loading test(ave. 202.3tonf) performed on the same piles over 40%. The difference between the capacity of Bi-directional loading test and dynamic loading test was caused by the insufficient impact energy during dynamic loading test and increase by interlocking effect by near piles during Bi-directional static loading test.

Laboratory and Field Performance Evaluation of Acryl Resin Based Solar Radiation Reflective Pavement (아크릴 수지를 이용한 차열성 포장의 실내 및 현장 공용성 평가)

  • So, Kyung-Rock;Lee, Hyun-Jong;Baek, Jong-Eun;Lee, Sang-Yum
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.19-28
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    • 2011
  • This study developed a solar radiation reflection pavement, so called a cool pavement, to lessen the urban heat island effect by coating a pavement surface with acrylic resins mixed with light-colored pigments. From a laboratory test, simulating solar heating process in pavements, the cool pavement reduced more than $12^{\circ}C$ of pavement temperature at $60^{\circ}C$ compared to a control porous pavement. With the increase of the mixing ratio of the pigments to acrylic resins, the temperature reduction effect increased, but its workability became worse due to higher viscosity. As a result, an appropriate mixing ratio was determined as 15%. The cool pavement had better durability than the control pavement: One quarter of Catabro loss and twofold dynamic stability. Its adhesion was also higher enough not to be debonded under traffic loading. In-situ noise and friction tests conducted in two field sites showed that the cool pavement reduced its noise level by 3.7dB in average and increased its friction level by 30% compared to the control pavement. The permeability of the cool pavement was little lower than the control pavement, but higher enough to satisfy the minimum requirement for porous pavements.

Resistivity Imaging Using Borehole Electrical Resistivity Tomography: A Case of Land Subsidence in Karst Area Due to the Excessive Groundwater Withdrawal (시추공 전기비저항 토모그래피를 이용한 비저항 영상화: 과잉취수에 의한 석회암 지반침하 지역 사례)

  • Song, Sung-Ho;Lee, Gyu-Sang;Um, Jae-Youn;Suh, Jung-Jin
    • Journal of the Korean earth science society
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    • v.32 no.6
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    • pp.537-547
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    • 2011
  • Electrical resistivity tomography surveys using boreholes were applied to reveal the cause of a catastrophic land subsidence accompanied by the excessive groundwater withdrawal in urban karst area and to map the connectivity of disseminated cavities over the study area. In order to understand the hydrogeological characteristics, resistivity using exsitu core samples, groundwater level for five boreholes, and hydraulic conductivity using slug test were measured. The hydraulic conductivity variation ranging from 0.8 to $9.3{\times}10^{-4}\;cm/s$ for five boreholes and a gentle slope of groundwater level indicated that there is no significant characteristics of hydraulic heterogeneity. Core samples of the lime-silicated rock were classified as three groups including cracked, weathered, and fresh and measured the resistivity values ranged from 103 to 161, 218 to 277, and 597 to 662 ohm-m, respectively. Drilling results that showed the cavity filled with clay materials and tomogram for this region indicated resistivity value lower than 50 ohm-m. From the inverted resistivity results for each section with five boreholes, cavity and fractured layer were distributed along the depth between 10 and 20 m overall area and cavities ranging from 4 to 6 m filled with clay materials.

Determinants and Processes of Regional Policy on the International Garden Exposition Suncheon Bay Korea 2013 (2013순천만국제정원박람회 정책화 과정과 동인에 관한 연구)

  • Lee, Jeong-Rock
    • Journal of the Korean Geographical Society
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    • v.49 no.6
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    • pp.849-864
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    • 2014
  • The objective of this paper is to investigate both the processes of regional policy and their determinants of the International Garden Exposition Suncheon Bay Korea 2013(IGEXPO 2013). IGEXPO 2013 was held in Suncheon from April to October 2013, and almost 440 million tourists visited to IGEXPO 2013. The processes of regional policy of the IGEXPO initiative were divided into four stages; the first stage from 1992 to 2002 was a beginning of conservation movement for Suncheon Bay; the second stage from 2003 to 2007 was a constructing of natural ecological park of Suncheon Bay; the third stage from 2008 to 2010 was a beginning of IGEXPO initiative and a confirming of the IGEXPO 2013; the four stage from 2011 to 2013 was a preparing and holding of IGEXPO 2013. The major determinants related to regional policy development process of IGEXPO initiative are the population n movement for Suncheon Bay, the rergional development strategy for central city in Gwangyang Bay area, the leadership for continuity of regional policy oriented to environmental and ecological city, and the cooperation and competition relationalship with neighboring city, in particular Yeosu city and 2012Yeosu EXPO planning. IGEXPO 2013 has been evaluated as having some performances such as the enhancement of city image, establishment of city park as a public goods, and formation of community leadership promoting continuous urban policy for environmental & ecological city.

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Effects of the ground water level on the stability of an underpass structure considering the degree of surface imperviousness (지표면 유출 특성을 고려한 지하수위 변화가 지하차도 구조물 안정성에 미치는 영향)

  • Jo, Seon-Ah;Hong, Eun-Soo;Cho, Gye-Chun;Jin, Kyu-Nam;Lee, Jung-Min;Han, Shin-In
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.1
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    • pp.95-107
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    • 2016
  • Ground water is one of important parameters in the designs of underpass structures because urban areas are characterized by soil ground which is relatively permeable than rock ground and a high level of ground water due to low elevation. Therefore, it is important properly to predict variations of the ground water when they can affect underpass structures. In this study, a series of numerical analyses are performed to predict the variations of ground water levels considering the degree of surface imperviousness and LID(Low Impact Development) application. In turn the stability of underground structure is assessed using predicted ground water level. The results show that an increase in the impervious surface area decreases the ground water level. The application of permeable pavement as a LID facility increases the ground water level, improving the infiltration capacity of rainfall into the ground. Seasonal variations of the ground water level are also verified in numerical simulation. The results of this study suggest that reasonable designs of underpass structures can be obtained with the suitable prediction and application of the ground water level considering the surface characteristics.

A Study on the Safe Blasting Design by Statistical Analysis of Ground Vibration for Vibration Controlled Blasting in Urban Area (II) (도심지 미진동 제어발파에서 진동분석을 통한 안전 발파설계에 관한 연구(II) - 진동측정 자료의 통계적 분석을 위주로 -)

  • 김영환;안명석;박종남;강대우;이창우
    • Explosives and Blasting
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    • v.18 no.2
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    • pp.7-13
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    • 2000
  • Abstract The characteristics of bed rock in the study area was classified by means of the crack coefficient estimated from the seismic velocities of in-situ and intact rocks. Various statistical methods were investigated in order to minimize the possible errors in estimating the predictive equation of blasting vibration and to enhance the determination coefficient $R^2$, for more reliable estimation. The determination coefficient showed the highest in the analysis for those groups using weighting function with the number of samples. The analysis for the weighting function employed with standard coefficient and variance also enhanced the determination coefficients significantly compared to the others, but the reliability was slightly lower than results obtained former method. Therefore the most reliable predictive equation of blasting vibration was found to be obtained from a regression analysis of the mean vibration level using the weighting of same distance groups within 15m with the same explosive charge weight per delay. The coefficients, K and n 317.4 and -1.66, respectively, when using the square root scaling, and 209.9 and -1.66, respectively, when using the cube root scaling. The analysis also showed that the square root scaling may be used in the distance less than 31m form the blast source, and the cube root scaling in the distance more than 31m for safe design.

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Investigation of Axially Loaded Jacked Pile Behavior by Pile Load Test (말뚝재하시험을 통한 압입강관말뚝의 연직지지거동 분석)

  • Baek, Sung-Ha;Do, Eun-Su;Kim, Seok-Jung
    • Journal of the Korean Geotechnical Society
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    • v.34 no.7
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    • pp.39-49
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    • 2018
  • Jacked pile that involves the use of hydraulic jacks to press the piles into the ground is free from noise and vibration, and is possibly installed within a limited construction area. Thus, as an alternative to conventional pile driving methods, pile jacking could become widely accepted for the construction projects in urban area (e.g., reconstruction or remodeling construction projects). Great concern has arisen over the prediction of axially loaded jacked pile behavior. Against this background, a series of pile load tests were hence conducted on a jacked steel pipe pile installed in weathered zone (i.e., weathered soil and weathered rock). From the test results, base resistance and shaft resistance for each test condition were evaluated and compared with the values predicted by the previous driven pile resistance assessment method. Test results showed that the previous driven pile resistance assessment method highly underestimated both the base and shaft resistances of a jacked pile; differences were more obviously observed with the shaft resistance. The reason for this discrepancy is that a driven pile normally experiences a larger number of loading/unloading cycles during installation, and therefore shows significantly degraded stiffness of surrounding soil. Based on the results of the pile load tests, particular attention was given to the modification of the previous driven pile resistance assessment method for investigating the axially loaded jacked pile behavior.

A Study for Safety Management on the Basis of Lateral Displacement Rates of Anchored In-situ Walls by Collapse Case Histories (붕괴 사례를 통한 앵커지지 가설흙막이벽체의 수평변위속도에 의한 안전관리 연구)

  • Chung, Dae-Seouk;Lee, Yong-Beom
    • Journal of the Society of Disaster Information
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    • v.14 no.3
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    • pp.367-378
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    • 2018
  • Purpose: The objective of this study is to present a reasonable safety management of the anchored in-situ wall systems constructed in the ground conditions consisting of multi-layered soils underlain by bedrocks in the urban area of Korea. Method: Field measurements collected from collapse case histories with deep excavations were analyzed for the safety management of the wall systems supported by the earth anchors in terms of lateral displacement rates. Results: The average maximum lateral displacement rate in a collapsed zone of the in-situ wall significantly increased upon the completion of the excavation. Particularly, the collapse of the in-situ wall system due to the sliding occurring along the discontinuities of the rock produced a considerably large lateral displacement rate over a relatively short period. Conclusion: For predicting and preventing the collapse of the wall system during or after the excavation work, the utilization of the safety management criteria of the in-situ wall system by the lateral displacement rate was found to be much more reasonable in judging the safety of earthworks than the application of the quantitative management criteria which have been commonly used in the excavation sites.

Cultural Landscape of Saegumjeong Area as a Recreation Place of Scholars in Joseon Dynasty (조선시대 선비들의 행락공간으로서 세검정 일대의 문화경관)

  • Lee, Jaei;Sung, Jong-Sang;Son, Yong-Hoon;Kim, Tae-Gyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.2
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    • pp.75-86
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    • 2016
  • The area surrounding Segeomjeong, one of the famous pavilions near the capital in the Joseon Dynasty, was a favorite place of scholars to visit and enjoy the beautiful natural landscape. The recreational culture of Segeomjeong area in traditional societies representing the prototype of urban tourism in modern society indicates cultural landscape which is a combination of the surrounding landscape and human activities. At this point, the purpose of this research on Saegumjeong area as a recreation place was to examine recreational activities and landscape elements before restoration. Through the relevant historical literature, there were several recreational activities such as traveling to enjoy scenery, taking a view of stream with waterfalls, doing creative writing of reciting poems and drawing about the greatness of nature and gathering on a broad and flat rock or Tangchundae. Also, the main landscape elements-such as Saegumjeong, stream, broad and flat rocks, pine trees, Tangchundae Peak, and mountains-were extracted through paintings of Saegumjeong drawn before restoration. Consequently, in this study, it was confirmed that the Segeomjeong area was the spot that scholars visited consistently, the center for travel, and the place for communication between scholars and national banquets. This study is significant, in that it drew conclusions on the cultural landscape of the Korean people through the ages and helped to discover the meaning and value of cultural landscape of recreation places based on Korean natural characteristics and cultural climate.