• Title/Summary/Keyword: Underground culverts

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A Study of Smokeproof in Underground Culvert (지하공동구의 연소방지설비에 관한 연구)

  • 홍경표;이영재;김선정
    • Fire Science and Engineering
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    • v.15 no.4
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    • pp.57-63
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    • 2001
  • Due to frequent fire incidents in underground culverts, many live are lost and the function of city is paralyzed, and consequently they bring tremendous damages to fortunes and live of people. It brings my attention that there are many problems presented when the current standard of smoke prevention facility is applied to prevent fire. Among many methods to prevent smoke in underground culverts this study concentrates on water-mist method witch is not currently applied in Korea and introduces installation method.

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Deformation of Corrugated Steel Plate Culverts in the Areas with Minimum Depth (최소토피고 미확보 구간에 시공한 파형강판 암거의 변형 특성)

  • Kim, Myoungil;Park, Duhee
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.7
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    • pp.23-30
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    • 2014
  • This paper deals with the characteristics of deformation of the underground corrugated steel plate culverts constructed in the areas where the minimum depth of within 1.5 m soil cover is not secured in the bottom of highways. The underground corrugated steel plate culverts at shallow depth are often designed and constructed with the consideration of the minimum depth of soil cover according to the design standards, which was made in order to minimize any deformation. Additionally, if under unfavorable conditions, slabs are set up for stress relaxation to disperse and minimize the weight of loads transferred to the corrugated steel plate culverts. Nevertheless, if the underground corrugated steel plate culverts are built in areas where the minimum depth of soil cover inevitably cannot be secured, there may occur some deformation. In this paper, a research was carried out to identify the characteristics of deformation in areas where the minimum depth of soil cover is not secured. The result shows that there existed the deterioration of pavement and in its smoothness around the corners of slabs for stress relaxation. To this end, this paper studied the structural stability of the underground corrugated steel plate culverts established in the areas with no minimum depth of soil cover secured, with the consideration of causes and solutions of pavement deterioration.

Probabilistic service life of box culvert due to carbonation of concrete cover

  • Woo, Sang-Kyun;Chu, In-Yeop;Lee, Yun;Lee, Byung-Jae
    • Advances in concrete construction
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    • v.12 no.6
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    • pp.517-525
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    • 2021
  • More underground structures are increasingly being constructed such as box culverts for electric power transmission, and the life extension of these structures is very important. It is well known that the steel embedded in concrete is usually invulnerable to corrosion because the high alkalinity of the pore solution in concrete generates a thin protective oxide layer on the surface of the steel. Recent observations in the field and experimental evidence have shown that even steel in concrete can be corroded through the carbonation reaction of cover concrete. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of underground box culverts in Korea was evaluated by measuring the car¬bonation rate and concrete cover depth in the field. Then, the carbonation-free service life for the cover depth of the steel was calcu¬lated with in situ information and Monte Carlo simulation. Additionally, an accelerated carbonation test for a cracked beam specimen was performed, and the effect of a crack on the service life of a box culvert was numerically investigated with Monte Carlo simulation based on experimental results.

Improvement of Structural Performance for the Precast Box Culvert (지하 프리캐스트 박스 암거의 구조적 성능 개선에 관한 연구)

  • 조병완;태기호;이계삼
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.393-398
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    • 2000
  • To use concrete box culverts effectively, precast goods are manufactured at a factory, then linked and anchored with prestressing tendon at a field. However, the corrosion of rebar and prestressing tendon in the box culverts utilizing portland cement concrete is issued when the cracks occur at a underground water level. It has been reported that reported that expansive concrete, compared with portland cement concrete, has many structural advantages such as increasing capacity of watertight, controling initial crack and improving durability due to its property of expansion. During flexure test with RC beam made from expansive concrete, in the case of a constant section of concrete element, the lower steel ratio is, and in the case of a constant steel ratio, the more incremental the section of concrete element, the more incremental the amount of chemical prestress by expansive concrete is. At the segment of the box culverts using expansive concrete, the numbers of crack and its gap is reduced, and ultimate load and initial crack load is much larger than the segment at which expansive concrete is nor used. Also lay-out of tendon with a curvature generate upward force so that deflection is reduced. Through the whole procedure, it could be confirmed that performance precast box culvert by means of using expansive concrete is improved.

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Performance evaluation of underground box culverts under foundation loading

  • Bin Du;Bo Hao;Xuejing Duan;Wanjiong Wang;Mohammad Roohani
    • Geomechanics and Engineering
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    • v.38 no.4
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    • pp.397-408
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    • 2024
  • Buried box culverts are crucial elements of transportation infrastructure. However, their behavior under foundation loads is not well understood, indicating a significant gap in existing research. This study aims to bridge this gap by conducting a detailed numerical analysis using the Finite Element Method and Abaqus software. The research evaluates the behavior of buried box culverts by examining their interaction with surrounding soil and the pressures from surface foundation loads. Key variables such as embedment depth, culvert wall thickness, concrete material properties, foundation pressure, foundation width, soil elastic modulus, and friction angle are altered to understand their combined effects on structural response. The methodology employs a validated 2D numerical model under plane strain conditions. Parametric studies highlight the critical role of culvert depth (H) in influencing earth pressure and bending moments. Foundation pressure and width demonstrate complex interdependencies affecting culvert behavior. Variations in culvert materials' elastic modulus show minimal impact. It was found that the lower wall of the buried culvert experiences higher average pressure compared to the other two walls, due to the combined effects of the culvert's weight and down drag forces on the side walls. Furthermore, while the pressure distribution on the top and bottom walls is parabolic, the pressure on the side walls follows a different pattern, differing from that of the other two walls.

A Study on Joint Position at Concrete Pavement with Box Culverts (박스 암거가 통과하는 콘크리트 포장의 줄눈 위치에 관한 연구)

  • Park, Joo-Young;Sohn, Dueck-Su;Lee, Jae-Hoon;Jeong, Jin-Hoon
    • International Journal of Highway Engineering
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    • v.14 no.2
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    • pp.45-53
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    • 2012
  • Hollows are easily made and bearing capacity is lowered near underground structures of concrete pavement because of poor compaction and long term settlement of the ground. Distresses occur and lifespan is shortened because of larger stress induced by external loadings expected than that in the design. In this paper, the distresses of the concrete pavement slab over box culverts were investigated at the Korea Expressway Corporation(KEC) test road. The transverse cracking of the slabs over the culverts was compared between up and down lines with different soil cover depth. The box culvert without soil cover and concrete pavement were modeled and analyzed by the finite element method(FEM) to verify the transverse cracking at the test road. Wheel loading was applied after self weight of the pavement and temperature gradient of the concrete slab at Yeojoo, Gyeonggi where the test road is located were considered. Positions of maximum tensile stress and corresponding positions of the wheel loading were found for each loading combination. Joint position minimizing the maximum tensile stress was found and optimal slab length over the culverts with diverse size were suggested.

Characteristics of Structural Behavior of Unplasticized Polyvinyl Chloride (PVC-U) Pipe Buried Underground (지중매설 경질폴리염화비닐관의 구조적 거동)

  • Kim, Sun-Hee;Cheon, Jinuk;Kim, Eung-Ho
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.4
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    • pp.16-23
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    • 2015
  • The industrialization and urbanization forced to increase the density of pipelines such as water supply, sewers, and gas pipelines. The materials used for the existing pipe lines are mostly composed of concretes and steels, but it is true that the development for more durable and efficient materials has been continued performed to produce long lasting pipe lines. Recently, underground pipes serve in diverse applications such as sewer lines, drain lines, water mains, gas lines, telephone and electrical conduits, culverts, oil lines, etc. In this paper, we present the result of investigation pertaining to the structural behavior of unplasticized polyvinyl chloride (PVC-U) flexible pipes buried underground. In the investigation of structural behavior such as a ring deflection, pipe stiffness, 4-point bending test, experimental and analytical studies are conducted. In addition, pipe stiffness is determined by the parallel plate loading tests and the finite element analysis. The difference between test and analysis is about 8% although there are significant variations in the mechanical properties of the pipe material. In addition, it was found by the 4-point bending test there is no problem in the connection between the pipes by coupler.

Long-term Ring Deflection Prediction of GFRP Pipe in Cooling Water Intake for the Nuclear Power Plant (원전 냉각수 취수용 GFRP관의 장기관변형 예측)

  • Kim, Sun-Hee;Park, Joon-Seok;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.3 no.3
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    • pp.1-8
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    • 2012
  • Recently, underground pipes are utilized in various fields of applications such as sewer lines, drain lines, water mains, gas lines, telephone and electrical conduits, culverts, oil lines, etc. Most of pipes are installed for long-term purposes and they should be safely installed in consideration of installation conditions because there are unexpected various terrestrial loading conditions. In this paper, we present the result of investigation pertaining to the structural behavior of glass fiber reinforced thermosetting polymer plastic (GFRP) flexible pipes buried underground. The mechanical properties of the GFRP flexible pipes produced in the domestic manufacturer are determined and the results are reported in this paper. In addition, ring deflection is measured by the field tests and the finite element analysis (FEA) is also conducted to simulate the structural behavior of GFRP pipes buried underground. From the field test results, we predicted long-term, up to 50 years, ring deflection of GFRP pipes buried underground based on the method suggested by the existing literature. It was found that the GFRP flexible pipe to be used for cooling water intake system in the nuclear power plant is appropriate because 5% ring deflection limitation for 50 years could be satisfied.

Behavior of Jointed Concrete Pavement by Box Culvert and Reinforced Slab (박스형 암거와 보강슬래브에 의한 줄눈 콘크리트 포장의 거동)

  • Park, Joo Young;Sohn, Dueck Su;Lee, Jae Hoon;Yan, Yu;Jeong, Jin Hoon
    • International Journal of Highway Engineering
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    • v.14 no.6
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    • pp.25-35
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    • 2012
  • PURPOSES : Hollows are easily made, and bearing capacity can be lowered near underground structures because sublayers of pavement settle for a long time due to difficult compaction at the position. If loadings are applied in this condition, distresses may occur in pavement and, as the result, its lifespan can decrease due to the stress larger than that expected in design phase. Although reinforced slab is installed on side of box culvert to minimize the distresses, length of the reinforced slab is fixed as 6m in Korea without any theoretical consideration. The purpose of this paper is investigating the behavior of concrete pavement according to the cover depth of the box culvert ad the length of the reinforced slab. METHODS : The distresses of concrete pavement slabs were investigated and cover depth was surveyed at position where the box culverts were located in expressways. The concrete pavements including the box culverts were modeled by finite element method and their behaviors according to the soil cover depth were analyzed. Wheel loading was applied after considering self weight of the pavement and temperature gradient of the concrete pavement slab at Yeojoo, Gyeonggi where a test road was located. After installing pavement joint at various positions, behavior of the pavement was analyzed by changing the soil cover depth and length of the reinforced slab. RESULTS : As the result, the tensile stress developed in the pavement slab according to the joint position, cover depth, and reinforced slab length was figured out. CONCLUSIONS : More reasonable and economic design of the concrete pavement including the box culvert is expected by the research results.

Estimation of Carbonation and Service Life of Box Culvert for Power Transmission Line (박스형 전력구의 콘크리트 탄산화에 의한 잔존수명 예측)

  • Woo, Sang Kyun;Lee, Yun;Yi, Seong Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.116-121
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    • 2012
  • The construction of underground structures such as box culverts for electric power transmission is increasing more and more, and the life extension of these structures is very important. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of two concrete box culverts in an urban area was evaluated by measuring the carbonation rate and concrete cover depth. Then, the carbonation-free service life at the depth of the steel was calculated, based on in situ information, by the Monte Carlo simulation. The service life of box culvert due to carbonation was estimated over 250 years via Monte Carlo simulation.