• Title/Summary/Keyword: Soil pavement

Search Result 208, Processing Time 0.023 seconds

A Study on Stability and Economic feasibility according to Height on the MSE Wall with Pacing Panel (고속도로 도로부에 시공된 패널식 보강토 옹벽의 높이별 안전율과 경제성 검토)

  • Park, Min-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.5
    • /
    • pp.54-63
    • /
    • 2018
  • In this study, the stability and economic feasibility of a MSE (Mechanically stability earth) wall with a pre-cast concrete pacing panel was investigated for a standard section of highway. Based on the design criteria, the MSE walls of the panel type were designed considering the load conditions of the highway, such as the dead load of the concrete pavement, traffic load, and impact load of the barrier. The length of the ribbed metal strip was arranged at 0.9H according to the height of the MSE walls. Because the length of the reinforcement was set to 0.9H according to the height of the MSE wall, the external stability governed by the shape of the reinforced soil was not affected by the height increase. The factor of safety (FOS) for the bearing capacity was decreased drastically due to the increase in self-weight according to the height of the MSE wall. As a result of examining the internal stability according to the cohesive gravity method, the FOS of pullout was increased and the FOS of fracture was decreased. As the height of the MSEW wall increases, the horizontal earth pressure acting as an active force and the vertical earth pressure acting as a resistance force are increased together, so that the FOS of the pullout is increased. Because the long-term allowable tensile force of the ribbed metal strip is constant, the FOS of the fracture is decreased by only an increase in the horizontal earth pressure according to the height. The panel type MSE wall was more economical than the block type at all heights. Compared to the concrete retaining wall, it has excellent economic efficiency at a height of 5.0 m or more.

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
    • /
    • v.18 no.1
    • /
    • pp.95-107
    • /
    • 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.

Analysis of the under Pavement Cavity Growth Rate using Multi-Channel GPR Equipment (멀티채널 GPR 장비를 이용한 도로하부 공동의 크기 변화 분석)

  • Park, Jeong Jun;Kim, In Dae
    • Journal of the Society of Disaster Information
    • /
    • v.16 no.1
    • /
    • pp.60-69
    • /
    • 2020
  • Purpose: Cavity growth process monitoring is to periodically monitor changes in common size and topography for general and observational grades to predict the rate of common growth. The purpose of this study is to establish a systematic cavity management plan by evaluating the general and observational class community in a non-destructive method. Method: Using GPR exploration equipment, the acquired surface image and the surrounding status image are analyzed in the GPR probe radargram in depth, profile, and cross section of the location. The exact location is selected using the distance and surrounding markings shown on the road surface of the initial detection cavity, and the test cavity is analyzed by calling the radar at the corresponding location. Result: As a result of monitoring tests conducted at a cavity 30 sites of general and observation grade, nine sites have been recovered. Changes in scale were seen in 21 cavity locations, and changes in size and grade occurred in 13 locations. Conclusion: The under road cavity is caused by various causes such as damage to the burial site, poor construction, soil leakage caused by groundwater leakage, waste and ground vibration. Among them, indirect factors could infer the effects of groundwater and localized rainfall.

Complementary measures for Environmental Performance Evaluation Index of External Space of Green Standard for Energy and Environmental Design for Apartment Complex - Focused on the Respect of Response to Climate Change - (공동주택 녹색건축인증기준의 외부공간 환경성능 평가지표 보완방안 - 기후변화 대응 측면을 중심으로 -)

  • Ye, Tae-Gon;Kim, Kwang-Hyun;Kwon, Young-Sang
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.34 no.1
    • /
    • pp.3-14
    • /
    • 2018
  • An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

A Study on Planting Landscaping Plants according to the Characteristics of Urban River Sections - A Case Study on Godeokcheon(Stream) in Seoul - (도시하천 구간 특성에 따른 조경 식물 식재방안 연구 - 서울시 고덕천을 사례로 -)

  • Moon, Yeong Ran;Han, Bong-Ho;Park, Seok-Cheol
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.52 no.2
    • /
    • pp.1-20
    • /
    • 2024
  • The present study was conducted to assess the adequacy of landscaping plants in city streams by investigating the species and growth status of landscaping plants, taking Godeokcheon in Seoul Metropolitan City as an example. The stream structure related to the planting ground and the impact of flood damage were analyzed. The adequacy of the planting species was analyzed based on the native species and moist land-inhabiting plants presented in the preceding study results. The adequacy, depending on the planting location and planting form, was analyzed using the growth states of adaptive and nonadaptive species by river topography. The planting location of those along the waterfront was the best, followed by the plants on waterside hills and embankment slopes. It is thought that the adaptability of dryland-inhabiting plants increased as the soil dried due to the impervious pavement of surrounding bikeways and trails. The species adequate for embankment slopes are thought to be native species and dryland-inhabiting plants. It is thought that, for waterside hills, the planting rate of wetland-inhabiting plants should be increased, and for waterfronts, the planting rate of dryland-inhabiting plants should be decreased. As for the planting form, the growth state was the best when mixed species were planted and the worst when other plants appeared. For city streams, the planting rates of native species and wetland-inhabiting plants should be increased, and adequate plant species for each location should be selected.

Impacts of Three-dimensional Land Cover on Urban Air Temperatures (도시기온에 작용하는 입체적 토지피복의 영향)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.37 no.3
    • /
    • pp.54-60
    • /
    • 2009
  • The purpose of this study is to analyze the impacts of three-dimensional land cover on changing urban air temperatures and to explore some strategies of urban landscaping towards mitigation of heat build-up. This study located study spaces within a diameter of 300m around 24 Automatic Weather Stations(AWS) in Seoul, and collected data of diverse variables which could affect summer energy budgets and air temperatures. The study also selected reflecting study objectives 6 smaller-scale spaces with a diameter of 30m in Chuncheon, and measured summer air temperatures and three-dimensional land cover to compare their relationships with results from Seoul's AWS. Linear regression models derived from data of Seoul's AWS revealed that vegetation volume, greenspace area, building volume, building area, population density, and pavement area contributed to a statistically significant change in summer air temperatures. Of these variables, vegetation and building volume indicated the highest accountability for total variability of changes in the air temperatures. Multiple regression models derived from combinations of the significant variables also showed that both vegetation and building volume generated a model with the best fitness. Based on this multiple regression model, a 10% increase of vegetation volume decreased the air temperatures by approximately 0.14%, while a 10% increase of building volume raised them by 0.26%. Relationships between Chuncheon's summer air temperatures and land cover distribution for the smaller-scale spaces also disclosed that the air temperatures were negatively correlated to vegetation volume and greenspace area, while they were positively correlated to hardscape area. Similarly to the case of Seoul's AWS, the air temperatures for the smaller-scale spaces decreased by 0.32% ($0.08^{\circ}C$) as vegetation volume increased by 10%, based on the most appropriate linear model. Thus, urban landscaping for the reduction of summer air temperatures requires strategies to improve vegetation volume and simultaneously to decrease building volume. For Seoul's AWS, the impact of building volume on changing the air temperatures was about 2 times greater than that of vegetation volume. Wall and rooftop greening for shading and evapotranspiration is suggested to control atmospheric heating by three-dimensional building surfaces, enlarging vegetation volume through multilayered plantings on soil surfaces.

Acid Drainage and Damage Reduction Strategy in Construction Site: An Introduction (건설현장 산성배수의 발생현황 및 피해저감대책)

  • Kim, Jae-Gon
    • Economic and Environmental Geology
    • /
    • v.40 no.5
    • /
    • pp.651-660
    • /
    • 2007
  • Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

Ecological Renewal Plan of Urban Parks for the Revitalization of Urban Green Axis in Gangdong-Gu (강동구 도시 녹지축 기능 활성화를 위한 도시공원의 생태적 리뉴얼 방안 연구)

  • Park, Jeong-Ah;Han, Bong-Ho;Kwak, Jeong-In
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.51 no.2
    • /
    • pp.12-27
    • /
    • 2023
  • In this study, among the construction-type parks in Gangdong-gu, targeting parks with high environmental and ecological value located on the urban green axis, a plan was prepared for the ecological renewal of urban parks, and a design that applied to them was proposed. The renewal target site was selected by analyzing the general condition of Gangdong-gu and urban parks, the land use and green area ratio, park green area, and the green axis of Gangdong-gu. Gangdong-gu has 54 parks, including 2 neighborhood parks and 52 children's parks. In the first stage of the current status review, 17 parks were extracted through locational value analysis, such as location and adjacency to the natural axis and green axis. In the second stage, eight parks were selected among the first-stage extraction parks based on the ratio of green spaces and open spaces within each park service area. In the third stage, two of the second stage extraction parks were selected based on whether the legal standard of the park area was met, and in the fourth stage, one of the third stage extraction parks was selected through an aging survey of the park. As for the urban ecological status of the renewal target site, the status of land use in the aspect of entropy reduction, the status of soil cover in the aspect of water circulation, and the status of planting structure in the aspect of biodiversity were investigated. As for the status of the three renewal sites, the green area was insufficient at 18.3-45.3%, and the facility area was 54.7%-81.7%, which was judged to have low urban temperature reduction effects. The impervious pavement area accounted for 34.5% to 48.9% of the park area, accounting for most of the facility area, and it was judged that the water circulation function was insufficient. The planting structure consisted of a single layer and a double layer structure, and although the tree layer was good, the lower vegetation was poor, and there was no planting site of edible plants or large hardwood trees, so the biodiversity was low. After the ecological renewal design of Seonrin Children's Park, Dangmal Children's Park, and Saemmul Children's Park, which were selected as the renewal targets in this study, the ecological area ratio of each park increased by 1.4 to 3 times than before the renewal. If the urban parks located on the urban green axis are examined from the perspective of the urban ecosystem and renewed ecologically, it is judged that the expected effect will be high in reducing entropy, improving water circulation, and laying the foundation for biodiversity in terms of the urban ecosystem.