• Title/Summary/Keyword: Box culvert

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Investigation of three-dimensional deformation mechanisms of box culvert due to adjacent deep basement excavation in clays

  • Bu, Fanmin;Yu, Wenrui;Chen, Li;Wu, Erlu
    • Geomechanics and Engineering
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    • v.30 no.6
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    • pp.565-577
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    • 2022
  • In this study, a series of three-dimensional numerical parametric study was conducted to investigate deformation mechanisms of an existing box culvert due to an adjacent multi-propped basement excavation in clays. Field measurements from an excavation case history are first used to calibrate a baseline Hardening Soil Small Strain (HS-small) model, which is subsequently adopted for parametric study. Results indicate that the basement-box culvert interaction along the basement centerline can be considered as a plane strain condition when the length of excavation (L) reaches 14 He (i.e., final excavation depth). If a plane strain condition (i.e., L/He=12.0) is assumed for analyzing the basement-box culvert interaction of a short excavation (i.e., L/He=2.0), the maximum settlement and horizontal movement of the box culvert are overestimated significantly by up to 15.7 and 5.1 times, respectively. It is also found that the deformation of box culvert can be greatly affected by the basement excavation if the distance between the box culvert and retaining wall is less than 1.5 He. The induced deformation in the box culvert can be dramatically reduced by improving the ground inside the excavation or implementing other precautionary measures. For example, by adding jet grouting columns within the basement and installing an isolation wall behind the retaining structures, the maximum settlements of box culvert are shown to reduce by 37.2% and 13.4%, respectively.

Earth Pressures on Box Culvert Induced by Excavation Geometry (되채움(굴착)의 형상에 따라 매설박스에 유발되는 토압)

  • 정성교;윤치관
    • Geotechnical Engineering
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    • v.12 no.5
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    • pp.27-40
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    • 1996
  • Box culvert has long since been used for various purposes , water and sewerage works, communication and electricity facilities, subway, railway, etc. In urban area, the construetion of box culvert generally consists of excavation-installation of the culvert-backfill. However, the existing design methods for earth pressure on the box culvert do not take into account the excavation(or backfill) geometry. ' A new method considering excavation geometry for earth pressure on box culvert is suggested here. The lateral earth pressures by the newly suggested method agree relatively with results of finite element analyses, but those of existing method are greatly overestimated. The vertical pressure on the top of the box culvert by the new method is similar to those of existing method and finite element analysis. However, the reactional pressure on the bottom of the box culvert depends largely upon the stiffness of the foundation soil. The reactional pressure by the new method agrees well with that of finite element analysis, only when the stiffness is low. From the finite element analysis it is shown that the lateral earth pressure on box culvert depends upon the excavated slope (G) and the net bottom distance (Bc).

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Behavior of Precast Concrete Box Culvert Using Expansive Cement (팽창시멘트를 이용한 프리캐스트 콘크리트 박스 암거의 거동에 관한 연구)

  • Jo, Byung-Wan;Tae, Ghi-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.159-169
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    • 2002
  • This study is intended to discuss the application of expansive additives for concrete to improve the durability of precast concrete box culvert by inducing the chemical prestress. The precast concrete box culvert using expansive cement are tested to verify the effect of expansive additives. The results show that the initial cracking load and yielding load of the expansive cement numbers are increased when they are compared with those of the normal concrete. In the prototype precast concrete box culvert experiment, initial crack control effect and strength of joint are increased, but the deflection is decreased by expansive cement. Brides, reinforcement ratio is decreased about 14.6 percent in compering with the case of using normal cement. If can be the concluded that the use of expansive additives to induce the chemical prestress was improve the durability in concrete box culvert.

Development of CAD System for 2Cell Box Culvert (2연 전력구의 자동화 설계)

  • 송영철;최홍식;노병철;우상균
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.322-329
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    • 1996
  • The objective of this study is to develop the CAD system for 2 cell box culvert by ultimate strength design method. C-language & AutoCAD Rl2 were used to create user-friendly computing environment. Consequently, users can easily design 2 cell box culvert under the various conditions, such as design load, total fill depth, underground water level, strength of concrete, and so forth. This system is believed to improve the efficiency and economy by the batch processing of structural analysis, quick drafting and computation of material quantity in the 2 cell box culvert design.

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A Study on Flexural Behavior of Precast Box Culvert with Blast Slag (고로슬래그 미분말을 혼입한 프리캐스트 박스 암거의 휨 강도에 관한 연구)

  • Tae, Ghi-Ho;Kim, Doo-Hwan
    • Journal of the Korean Society of Safety
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    • v.27 no.2
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    • pp.25-32
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    • 2012
  • In this study, the effect of blast furnace slag on precast concrete culvert was assessed by measuring the flexural strength using to full scaled box culvert. As a result, the initial cracking load and yield load of reinforced concrete box converts are increased in comparison with those of the normal concrete box culvert, but the ultimate load is decreased slightly. It can be concluded that use of blast furnace slag induce to flexural strength in precast concrete box culvert greatly improved the serviceability.

Thermal Crack Control of Box-Culvert by Using Rapid-Strength Belite Cement (조강형벨라이트 시멘트 적용을 통한 Box-Culvert 의 온도균열 제어)

  • 김태홍;하재담;김동석;이종열;박경래;이주호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.521-526
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    • 2001
  • Box-culvert is very important structure used almost every road construction. However this is treated very simple structure in design and construction. So many crack such as nonstructural crack has been occurred. This crack is very harmful on durability of concrete. In this study, thermal crack, one of the nonstructural crack, of box-culvert controled by using rapid-strength belite cement concrete. In this process, not only heat of hydration and thermal stress but also material mechanics properties and characteristics of durability were tested. and same model box-culvert using OPC concrete is constructed in same condition for comparison.

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Explicit Analysis of Flows in Box Culvert (사각형 암거흐름의 양해적 해석)

  • Yoo, Dong-Hoon;Uhm, Ho-Sik
    • Journal of Korea Water Resources Association
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    • v.36 no.3 s.134
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    • pp.481-494
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    • 2003
  • Flow through the culvert is very complex depending on the characteristics of hydraulic conditions. A design method using a monograph is normally employed due to the wide range of flow characteristics and the difficulty of calculating inlet water depth. The present study suggests the method for determining the inlet water depth of box culvert using Bernoulli's equation. By employing the explicit equation of inlet water depth, a standard design method of box culvert is developed for a wide range of flow characteristics. Explicit solution techniques are proposed to determine the width and height, slope and discharge of box culvert.

Expert System for R/C Box-Culvert Design (R/C Box 암거설계 전문가시스템)

  • Kim, Woo;Kim, Dae-Joong;Jung, Jae-Pyoung
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.10a
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    • pp.261-266
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    • 1994
  • The objective of this study is to develop the expert system for R/C box culvert design. This program provided various functions to improve automatic design. The program is composed of five steps. The characteristics of each step are as follows; 1) Preprocessing Step, 2) Analysis Step, 3) View of Memberforce Step, 4) Postprocessing Step, 5) Printing of Design-Sheet Step. Finally, Expert System and Knowledge Database System is developed for the drawing of optimal R/C box-culvert design.

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An Experimental Study on Suppression of Cavity Development by Enlargement of Base Plate of Box-Culvert Installed at River Levee (하천제방 배수통문의 저판확폭을 통한 공동발생 억제기법 연구)

  • Kim, Jin-Man;Choi, Bong-Hyuck;Lee, Dae-Young;Jin, Young-Ji
    • Journal of the Korean Geotechnical Society
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    • v.27 no.3
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    • pp.55-61
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    • 2011
  • Generally, the Box-Culvert in levee is destroyed by various reasons. Especially when Box-Culvert is installed over the pile foundation in soft ground, the failure occurrs for 1) the weakness of compaction in Box-Culvert side by the differential settlement between outer ground and inner soil prism, 2) hydraulic fracturing and disturbance of Box-Culvert side soil by the repeated acting of seepage pressure at flood time. Also the side of Box-Culvert is difficult to compact and the shear resistance is reduced by more than 1/3 for the reduction of friction caused by the difference of material property. In this study, a series of model tests are conducted for the analysis of the development mechanism of outer ground and inner soil prism by the differential settlement using the pile foundation in soft ground, and cavity suppressed technique is suggested by the analysis of base plate enlargement effect.

Optimal Joint Position in Concrete Pavement Slab over Skewed Box Culvert (수평으로 경사진 박스암거 위 콘크리트 포장 슬래브의 최적 줄눈위치)

  • Yeom, Woo Seong;Jeong, Ho Seong;Yan, Yu;Sohn, Dueck Soo;Lee, Jae Hoon;Jeong, Jin Hoon
    • International Journal of Highway Engineering
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    • v.15 no.5
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    • pp.47-55
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    • 2013
  • PURPOSES : The purpose of this study is to investigate the optimal joint positions which can minimize distresses of concrete pavement containing box culvert with horizontally skewed angles. METHODS : The concrete pavement containing the box culvert with different skewed angles and soil cover depths was modeled by 3 dimensional finite element method. The contact boundary condition was used between concrete and soil structures in addition to the nonlinear material property of soil in the finite element model. A dynamic analysis was performed by applying the self weight of pavement, negative temperature gradient of slab, and moving vehicle load simultaneously. RESULTS : In case of zero skewed angle ($0^{\circ}$), the maximum tensile stress of slab was the lowest when the joint was positioned directly over side of box culvert. In case there was a skewed angle, the maximum tensile stress of slab was the lowest when the joint passed the intersection between side of the box culvert and longitudinal centerline of slab. The magnitude of the maximum tensile stress converged to a constant value regardless the joint position from 3m of soil cover depth at all of the horizontally skewed angles. CONCLUSIONS : More reasonable and accurate design of the concrete pavement containing the box culvert can be possible based on the research results.