• Title/Summary/Keyword: retaining wall

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Pullout Characteristics of Geogrid with Attached Passive Reinforcement (마찰돌기를 부착한 지오그리드의 인발특성 평가)

  • Moon, Hongduk;Yoo, Chulho
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.11
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    • pp.43-51
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    • 2014
  • In this study, a series of pullout experiments were conducted on geogrid with attached passive reinforcement with respect to silt containments. Experiments were performed on man-made sand ground containing different silt of 0 %, 17 %, 35 % under various normal stresses 30 kPa, 60 kPa, 120 kPa respectively. The pullout test results showed that passive reinforcement increased the pullout strength over all silt contained condition and showed up to 20 % increases for same soil condition. The test results converted to the coefficient of interaction of pullout test to investigate the effect of reinforcement and the case of passive reinforcement showed 0.7~1.6 distribution depend on a silt contents. Therefore it is concluded that the overall length of geogrid can be reduced under the low vertical stress conditions.

Characteristics Analysis of the Design Factors Followed by Present Techniques of Waterscape Facilities in the Apartment Complex (공동주택단지 내 수경시설 연출기법에 따른 설계요소별 특성분석)

  • Lee, Gyeong-Jin;Choi, Ah-Young;Song, Byeong-Hwa
    • KIEAE Journal
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    • v.8 no.4
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    • pp.11-18
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    • 2008
  • This research case-study places are chosen Seoul Metropolitan City and Yong-In City where the distinction characteristics of outdoor spaces are introduced in Apartment Complex. In this study, the standard of waterscape facilities will be set through preliminary researches and detail design factors are prepared for each characteristics. Analyze and research the characteristics of design factors through the field research of places. The Group data from Cluster Analysis, which is about waterscape facilities, is analyzed and classified by types of waterscape facilities in common residence. and then each type of characteristics and representatives of waterscape facilities founded. Waterscape facilities are charactered in 4 main types. I Type is appeared to the natural artificially mountain stream, slope and a rest space type, and feelings type. This type has twenty sites. II Type is appeared to the fewest sites(11 sites). This type is appeared to the Eco-pond, Border planting next to the waterscape facilities. III Type is appeared to the largest sites(28 sites), that is, play style water facilities of no-plantation patterns. IV Type is appeared to the retaining wall type, the rest space of bench type. Research result led, detailed plan element 64 are selected with design elements Seoul Metropolitan City and the Yong-In City at the time of the fact that well is only reflected commonly from external spaces, the type by quality which leads a statistical analysis the type quality was well reflected relatively was judged.

Safety Management of the Retaining Wall Using USN Sonar Sensors (USN 초음파 센서를 활용한 흙막이 안전관리)

  • Moon, Sung-Woo;Choi, Eun-Gi;Hyun, Ji-Hun
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.6
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    • pp.22-30
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    • 2011
  • In the construction operation, foundation work should be done in advance for the building structure to be installed. This foundation work include a number of activities such as excavation, ground water prevention, piling, wale installation, etc. Caution should be taken in the operation because the dynamics of earth movement can cause a significant failure in the temporary structure. The temporary structure, therefore, should be constantly monitored to understand its behavior. This paper introduces the USN-based monitoring system to automatically identify the behavior of the temporary structure in addition to visual inspection. The autonomous capability of the monitoring system can increase the safety in the construction operation by providing the detailed structural changes of temporary structures.

Development and Evaluation of Technique for Analyzing Laterally Loaded Piles (횡방향력을 받는 말뚝의 해석기법 개발 및 평가)

  • Lee, Seunghyun;Kim, Byoungil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.2C
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    • pp.79-84
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    • 2012
  • A technique for analyzing laterally loaded piles was developed in order to accommodate various loading conditions and unique p-y curves obtained from local site. Developed technique was applied to several problems associated with laterally loaded piles to confirm the reliability of the developed technique. And the influences of the parameters considered in the applications on analysis results were investigated. It can be seen that length of the increment of one half of pile diameter is optimum for accuracy of analysis. Problems associated with safe penetration of pile and buckling of a free standing pile were analyzed by the developed technique. Also, analysis results obtained from considering various pile head conditions of a pile which supports retaining wall were compared. The developed technique can be used as a more flexible tool for analyzing laterally loaded piles than commercial program.

Using Gabion Systems with Vegetation Base Materials on Stability Analysis for the Forest Road Cut-slope Rehabilitation Techniques (임도비탈면의 복원을 위한 식생기반재 돌망태의 안정성 분석)

  • Park, Jae-Hyeon;Jeong, Yong-Ho;Choi, Hyung-Tae
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.2
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    • pp.106-113
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    • 2009
  • In this study, stability of the new gabion system with vegetation base materials was analysed. New gabion system with vegetation base materials is a new approach which has been developed to achieve lope stabilization and revegetation of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials. Results from stability analysis are as follows. For the soil density, the angle of internal friction and unit weight of the rock fill was assumed to be $1.90g/cm^3$, $30^{\circ}$ and $2.30t/m^3$, respectively, the slope stability analysis showed that the new gabion system couldn't require any poles to fix it up, and could keep stable during both rainy and dry seasons. As the results of checks against overturning and sliding, the retaining wall with. the new gabion system could produce suitable factors of safety for overturning and sliding. Vegetation established on the surface of the new gabion systems indirectly can help to increase slope stability by prevention of surface erosion. Consequently, the new gabion system with vegetation base materials could achieve the desired effect on slope stabilization as much as existing gab ion system could do, and could promote rapid establishment of vegetation on cut-slopes.

A Study on The Process of Land-dividing of Urban-Hanok Area in 11 Gahoe-dong, Seoul (서울 가회동11번지 도시한옥주거지의 필지형성과정 연구)

  • Song, Inho;Jung, Kee Hwang
    • Journal of architectural history
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    • v.23 no.5
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    • pp.47-60
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    • 2014
  • Urban-Hanok emerged as a result of urbanization of Hanok in the modern period. In particular, Urban-Hanok has been mass-produced from the early 1920s, when the population is concentrated in cities, until the middle. Large-scale development by the professional developer has been developed in large-scale land rather than individual client because housing shortage was serious problem. 11 Gahoe-dong was made in 1935-36 is representative Urban-hanok area of Bukchon. It was formed through division of large-scale Land in 1930's. In the 1930's, the large-scale development projects of Urban-Hanok was triggered by the two events. One is Land Investigation Project performed by the Japanese government to capitalization of property, another is the pro-japanese bought the large scale-land in Gahoe-dong at bargain price from The Japanese government. Each lot has still a topographical characteristics such as land-dividing quality, the way of development, characteristic quality of urban-tissue. 11 Gahoe-dong, Urban-hanok area was developed two ways. First, development have been adapted to the topography. The lots have reflected topographical conditions such as land cutting area, a retaining wall, land-diving was maintaining the original topography almost. Second, it was street oriented development. The lots have developed sequentially along the street. So, the lots's shape and size is different each. For this reason, this area distribute various type of Hanok.

A Study on Engineering Characteristics of Load Reducing Material EPS (도로성토하중경감재 EPS의 공학적 특성에 관한 연구)

  • Jang, Myeong-Sun;Cheon, Byeong-Sik;Im, Hae-Sik
    • Geotechnical Engineering
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    • v.12 no.2
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    • pp.59-70
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    • 1996
  • The EPS has the unit weight of only 20~30kg/m3 and is used as one of the methods of reducing road embankment loads. Parts of it's applications are for backfill materials of structures like abutment, retaining wall, etc., to reduce horizontal earth pressure and for banking materials to secure the safety of settlement and bearing capacity by minimizing the stress Increment. However, the Korean Standards (KS) has not yet proposed any testing method for use of EPS as a engineering banking material. Only its testing and quality ordinance as a heat insulation material has been standardized. Therefore, in Korea, EPS is used as banking material without any systematic testing data as a civil engineering material. In this point of view, this paper deals with the engineering characteristics of EPS through many laboratory tests on strength, strain, absorption, and creep. from the results achived through tests, this paper proposes the enactment of a suitable quality testing ordinance and the criteria of unconfined design strength of EPS for use as engineering material.

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Development of a trench shield machine for the near-surface railway construction (저심도 철도 건설을 위한 트렌치 쉴드 장비 개발연구)

  • Lee, So-Oh;Sagong, Myung;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.2
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    • pp.175-187
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    • 2015
  • In this paper, the development of trench shield machine for near-surface railway construction were presented. The Near-surface railway can be constructed by cut and cover construction method, because it is installed at the depth of 5~7 m below roads. The cut and cover construction method mostly use temporary supports. The limitation of the cut and cover method is high installation cost and long construction period. To overcome these disadvantages, development of the trench shield machine is proposed and expected to shorten the construction time and cost of near-surface railway system. The sliding retaining wall of trench shield equipment replaces the role of temporary support (solider piles and lagging) and excavator equiped to the bottom front of the machine shorten the excavation time. This paper deals with design of the bit attached to the excavator and required capacity of the motor.

An Evaluation of Landslide Probability by Maximum Continuous Rainfall in Gangwon, Korea (강원지역의 최대연속강우량에 의한 산사태 발생가능성 평가)

  • Yang, In-Tae;Park, Jae-Kook;Jeon, Woo-Hyun;Chun, Ki-Sun
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.4
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    • pp.11-20
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    • 2007
  • Most natural disasters in Korea are caused by meteorological natural phenomena, which include storms, heavy rains, heavy snow, hail, tidal waves, and earthquakes. Rainfall is the most frequent cause of disasters and accounts for about 80% of all disasters. Particularly in recent years, Korea has seen annual occurrences of natural disasters associated with landslides (slope and retaining wall collapse and burying) due to meteorological causes from the increasing intensity of heavy rains including local heavy rainfalls. In Korea, it is critical to analyze the characteristics of landslides according to rainfall characteristics and to take necessary and proper measures for them. This study assessed the possibility of landslides in the Gangwon region with a geographic information system by taking into account the inducer factors of landslides and the maximum continuous rainfall of each area. It also analyzed areas susceptible to landslides and checked the distribution of landslide-prone areas by considering the rainfall characteristics of those areas.

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Analysis of Unintended Lake Formation Problem and Its Environmental Effects a Case Study

  • Bushira, Kedir Mohammed;Kasaya, Alemayehu
    • Journal of Wetlands Research
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    • v.22 no.3
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    • pp.217-224
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    • 2020
  • Waterlogging and unintended lake formation become the main problem in some parts of the world. Starting from 1989, the waterlogging problem was observed in the farmland of the Jarso community of Konso Woreda adjacent to the Segen River in Ethiopia. Therefore, the objectives are determining the extent and causes of unintended lake formation using GIS/RS in addition to a preliminary field survey to mitigate the problem. The analysis of satellite images revealed that over the years invasion of the irrigable land by unwanted water had increased, as, in 1989, the size of the wetland area was about 8 Km2; in 2000 the size of the un-intended lake was only 8.23 ㎢. Alarmingly the size of the lake increased to 19.68 Km2 in 2014. Silting up of Weir and changing the flow of River Segen and Human Intervention and changing the natural flow of River Yanda were the main causes of this unwanted prolonged water-logging. The ecological and social environment has been degrading as the people of the waterlogged area have been experiencing some settlement and losing their land. Another problem encountered was flooding from River Barka and invasion of the farmland. Sediment control best management practices (BMPs) i.e, Removal of sediment, providing sandbags and well-scheduled maintenance; Changing the junction point of Yanda and Segen River were suggested for the long-term and short term possible remedial measures. Gabion retaining wall on the bank of the Segen River to the face of Barka River was suggested to protect the farmland from flooding.