• Title/Summary/Keyword: 프리캐스트 아치

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Pull-out Capacity of Cast-in-place Anchor for Construction of Precast Concrete Segment Arch (프리캐스트 콘크리트 패널 분절 아치 시공을 위한 선설치 앵커의 인발 강도 평가)

  • Ahn, Jin-Hee;Yim, Hong Jae;Bang, Jin Soo;Jeon, Seok Hyeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.2
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    • pp.94-102
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    • 2020
  • Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

Numerical analyses for mechanical behavior of cut-and-cover tunnel with precast arch type (프리캐스트 아치형 개착식 터널의 역학적 거동에 관한 수치해석)

  • Hwang, Jae-Hong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.315-325
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    • 2009
  • The thickness of the material can be thinned because arch cut-and-cover tunnel has the support mechanism by the axial force, and the ground reaction force due moderate deformation can be expected thereby making it be dynamically advantageous, therefore the arch cut-and-cover tunnel has become more widely used. An important characteristic of the arch cut-and-cover tunnel is that the thickness of the material can be thinned because precast arch type has the support mechanism by the axial force. However, there is a different stress state surrounding the structures between normally excavated tunnels and cut-and-cover tunnels, it should be considered at designing. Therefore, finite element method was carried out to examine the mechanical behavior of the precast arch cut-and-cover tunnel considering construction procedure.

Investigation for the deformation behavior of the precast arch structure in the open-cut tunnel (개착식 터널 프리캐스트 아치 구조물의 변형 거동 연구)

  • Kim, Hak Joon;Lee, Gyu-Phil;Lim, Chul Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.93-113
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    • 2019
  • The behavior of the 3 hinged precast arch structure was investigated by comparing field measurements with numerical analyses performed for precast lining arch structures, which are widely used for the open-cut tunnel. According to the field measurements, the maximum vertical displacement occurred at the crown with upward displacements during the backfilling up to the crown of the arch and downward displacements at the backfill height above the crown. The final crown displacement was 19 mm upward from the original position. The horizontal displacement at the sidewall, which had a maximum horizontal displacement, occurred inward of the arch when compacting the backfill up to the crown and returned to the original position after completing the backfill construction. According to the analysis of displacement measurements, economical design is expected to be possible for precast arch structures compared to rigid concrete structures due to ground-structure interactions. Duncan model gave good results for the estimation of displacements and deformed shape of the tunnel according to the numerical analyses comparing with field measurements. The earth pressure coefficients calculated from the numerical analyses were 0.4 and 0.7 for the left and the right side of the tunnel respectively, which are agreed well with the eccentric load acting on the tunnel due to topographical condition and actual field measurements.

Seismic analysis and dynamic behavior characterization of rib-reinforced pre-cast tunnels (리브 보강 프리캐스트 터널의 내진 해석 및 동적거동 특성 파악)

  • Song, Ki-Il;Jung, Sung-Hoon;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.287-301
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    • 2009
  • The novel cut-and-cover tunnel construction method using rib-reinforced pre-cast arch segments has been recently developed and applied for practice to secure a structural stability of high covering and wide width section tunnels. Cut-and-cover tunnels are usually damaged by the seismic behavior of backfill grounds in case of a low covering condition. Seismic analyses are performed in this study to characterize the dynamic behavior of rib-reinforced pre-cast arch cut-and-cover tunnels. Seismic analyzes for 2 lane cast-in-place and rib-reinforced pre-cast arch cut-and-cover tunnels are carried out by using the commercial FDM program (FLAC2D) considering various field conditions such as the covering height embankment slope and excavation slope. It can be concluded that the amplification of seismic wave is reduced due to an increase in the structural stiffness induced by rib-reinforcement. The results show that the rib-reinforced pre-cast arch cut-and-cover tunnels are more effective against the seismic loading, compared to the cast-in-place cut-and-cover tunnels.

Strength Evaluation on Sectional Members of Prefabricated Precast Concrete Arch with Reinforced Joint (보강된 이음부가 적용된 조립식 프리캐스트 콘크리트 아치의 단면 강도 평가)

  • Joo, Sanghoon;Chung, Chulhun;Bae, Jaehyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.5
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    • pp.1363-1372
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    • 2014
  • In the previous study, the structural performance of proposed precast concrete arch with reinforced joint was evaluated by structural experiment. In this paper, finite element analysis considering both material and contact nonlinearity was carried out on the specimens of the previous study. Based on the result of analysis and experiment, friction coefficient between concrete blocks was determined. To evaluate the strength of sectional member, elastic analysis was carried out on the arch using linear elastic analysis program. The section force was compared with the nominal strength of arch section. It was concluded that the maximum load of all the specimens exceed the nominal strength of arch section. Those results of the strength evaluation were similar to the results of structural experiments. Therefore, it is concluded that the elastic analysis and ultimate strength model can effectively evaluate the strength for the proposed precast concrete arch composed of concrete blocks and reinforced joint in design.

Evaluation of Structural Behavior of Connections in Precast Arch Structures (프리캐스트 아치구조의 이음부 구조 거동 평가)

  • Shim, Chang Su;Kim, Dong Chan;Choi, Dae;Jin, Kyung Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.5
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    • pp.747-756
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    • 2016
  • In this paper, a connection details for precast arch structures was proposed. Experiments were performed to evaluate structural performance of the loop connection details satisfying current design requirements and of alternative details for improvement of constructability. Precast arch specimens considering the current design requirements showed higher structural capacity than a cast-in-place arch specimen. Crack width at the connection of arch crown showed smaller value than 0.2 mm due to increased compression force by the applied vertical load. Strengthening by wire-mesh at notch area of the connection improved initial crack control capability. Connection detail with couplers and headed bars showed similar capacity to the reference specimen. The alternative details to improve constructability of reinforcements can be used without decreasing structural performance. Specimens with smaller internal diameter of mandrel and shorter loop splicing than the current design codes showed worse behavior in terms of crack width control.

Mechanical behaviour of tunnel liner using precast segment reinforced by rib (리브 보강 프리캐스트 터널 Liner의 역학적 거동 특성)

  • Lee, Gyu-Phil;Lee, Sung-Won;Shiin, Hyu-Soung;Hwang, Jae-Hong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.10 no.3
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    • pp.295-302
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    • 2008
  • Due to the limitation of construction efficiency and structural safety, the application of the high covering and wide width tunnels was limited prior to the introduction of precast cut and cover tunnels. Therefore, a cut and cover tunnel structure with rib reinforcement is proposed to mechanically improve the safety on condition of high covering and wide width tunnel. In this study, large-scale experiments are carried out to examine the mechanical behavior of the cut and cover tunnel structure with rib reinforcement under static load condition. Based on the results obtained from this study, the ultimate load of tunnel structure increases to about 3.3 times by rib reinforcement. Consequently, safety of tunnel structure increases compared to non-installed cases due to confining crown part by rib reinforcement.

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Structural Performance of Precast Concrete Arch with Reinforced Joint (보강된 이음부를 가진 조립식 프리캐스트 콘크리트 아치의 구조성능)

  • Chung, Chulhun;Joo, Sanghoon;Choi, Dongchan;Lee, Jongyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.29-47
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    • 2014
  • The masonry stone arch bridge, due to its superior durability and aesthetics, has been one of the oldest and popular types of short span bridges. In Europe, this type of bridges have been continuously constructed, and numerous related researches have been conducted until recently. However, there are few construction cases in Korea since the economic efficiency and the construction effectiveness is not contentable. Therefore, this study proposed the reinforced joint to improve structural performance of the conventional arch systems which is proposed by previous researchers. The structural performance of the proposed reinforced joint, which consists of the transverse loop joint and the longitudinal reinforcement, is validated by experimental test of an arch bridge which is constructed using precast concrete segments. Based on this results of the experimental test, it is concluded that the strength of arch bridges can be enhanced by applying the proposed reinforced joints since the reinforced joint restrains hinge behavior and relative displacement between segments with a little reinforcement.

Flexural Behavior of RC Arch Deck Subjected to Static Loading (철근콘크리트 아치 데크의 정적 휨 거동)

  • Eom, Gi-Ha;Yang, Dal-Hun;Kim, Sung-Jae;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.29 no.4
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    • pp.371-378
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    • 2017
  • In this study, the flexural behavior of the RC Arch Deck under static loading was evaluated. Flexural test was carried out using an actual size RC Arch Deck with a length of 2.5 m, a center thickness of 100 mm and an end thickness of 160 mm. The test results showed that it's ultimate load was 1.74 times higher than the ultimate design load. On the other hand, it showed that the flexural behavior has different behaviors (i.e. different stiffness). This type of structural behavior indicates that it has inter-dependency between the deck and the supporting girder. Therefore, it is necessary to confirm the precise behavior by the static loading test of the RC Arch Deck, excluding the girder effect in the future study. The overall results showed that RC Arch Deck has excellent structural performance due to the structural advantages of the arch shape. In the future, the RC Arch Deck can be applied as a long span slab.