• Title/Summary/Keyword: 흙막이벽체공법

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Behavior Analysis Using FEM for Earth Retaining Wall of Soft Rock Fracture Zone (FEM을 이용한 연암 파쇄대 지반의 흙막이 벽체 거동 분석)

  • Jang, Gi-Soo;Park, Min-Chul;Shin, Hyo-Hee;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.4
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    • pp.30-37
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    • 2013
  • A soft rock fracture zone is an important element for rock slope or earth retaining, however stability studies of earth retaining wall have been lack. Therefore, this study is analyzed for a behavior of earth retaining wall with condition of fracture zone or no fracture zone and then a numerical analysis (Finite Element Method) was performed considering interaction with field monitoring data between ground and structures. As a result, applied horizontal displacement on retaining wall is correspond between result of numerical analysis and field monitoring data and displacement point stress distribution with fracture zone condition analyzed to be stable side but no fracture zone condition is expressed to be unstable side. The results of this study is purpose for applying safety construction as a top priority at field when designing for future.

A Study on the Self-contained Earth Retaining Wall Method Using Bracing (브레이싱을 이용한 자립식 흙막이 공법에 관한 연구)

  • Kim, Jong-Gil
    • Journal of Digital Convergence
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    • v.17 no.3
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    • pp.205-213
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    • 2019
  • In a construction site, excavation work has a close relation with temporary earth retaining structure. In order to build the underground structure most effectively in a narrow space, prevent soil relaxation of the external behind ground in excavation work, and maintain a ground water level, it is required to install a temporary earth retaining structure that secures safety. To prevent soil washoff in underground excavation work, the conventional method of temporary earth retaining structure is to make a temporary wall and build the internal support with the use of earth anchor, raker, and struct for excavation work. RSB method that improves the problem of the conventional method is to remove the internal support, make use of two-row soldier piles and bracing, and thereby to resist earth pressure independently for underground excavation. This study revealed that through the field application cases of RSB method and the measurement result, the applicability of the method for installing a temporary earth retaining structure, the assessment result, and displacement all met allowable values of measurement, and that the RSB method, compared to the conventional method, improved constructability and economy.

Numerical Analysis of Self-Supported Earth Retaining Wall with Stabilizing Piles (2열 자립식 흙막이 공법의 거동특성에 관한 수치해석적 연구)

  • Sim, Jae-Uk;Jeong, Sang-Seom;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.31 no.5
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    • pp.35-46
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    • 2015
  • In this study, the behavior of self-supported earth retaining wall with stabilizing piles was investigated by using a numerical study and field tests in urban excavations. This earth retaining wall can provide stable support against lateral earth pressures through its use of stabilizing piles that provide passive resistance to lateral earth pressures arising due to ground excavations. Field tests at two sites were performed to verify the performance of instrumented retaining wall with stabilizing piles. Furthermore, detailed 3D numerical analyses were conducted to provide insight into the in situ wall behavior. The 3D numerical methodology in the present study represents the behavior of the self-supported earth retaining wall with stabilizing piles. A number of 3D numerical analyses were carried out on the self-supported earth retaining wall with stabilizing piles to assess the results stemming from wide variations of influencing parameters such as the soil condition, the pile spacing, the distance between the front pile and the rear pile, and the pile embedded depth. Based on the results of the parametric study, the maximum horizontal displacement and the maximum bending moment significantly decreased when the retaining wall with stabilizing piles is used. Moreover, the horizontal displacement reduction effect of influencing parameters such as the pile spacing and the distance between the front pile and the rear pile is more sensitive in sandy soil, with a higher friction angle compared to clayey soil. In engineering practice, reducing the pile spacing and increasing the distance between the front pile and the rear pile can effectively improve the stability of the self-supported earth retaining wall with stabilizing piles.

Effects of Strut Preloading on the Restraining of Adjacent Ground Displacement at Braced Excavations (버팀 굴착시 버팀대 선행하중의 인접지반 변위 억제 효과)

  • 백규호;조현태
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.31-40
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    • 1999
  • The bracing system using screw jack is not effective for the restraining of adjacent ground displacement. since the screw jack dose not induce sufficient preloading on struts. In order to protect excessive displacement of adjacent ground at braced excavation, new preloading jack was developed in the country. In this paper, the new preloading jack and the measurement results of the lateral displacement of braced wall at three deep excavation sites in Seoul city are introduced. The measurement results showed that the maximum displacements of braced wall are smaller than 0.15% of excavation depth, therefore the wall displacements can be minimized by preloading which is acted on bracing. If the bracing system with new preloading jack is used in braced excavation, it is effective for reducing the cost and period of construction.

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A Study on the Field Application of High Strength Joint Buried Pile Retaining Wall Method (고강도 결합 매입말뚝 흙막이 공법의 현장적용성 검토에 관한 연구)

  • Lee, Gwangnam;Kim, Daehyeon
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.671-684
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    • 2022
  • This study verified the stability of a high-strength combined buried pile retaining wall and its applicability in the field. A cast-in-place (C.I.P) retaining wall and the high-strength combined embedded pile retaining wall were compared and analyzed numerically. The numerical analysis assessed the ground behavior and stability (and thus field applicability) of a high-strength combined buried pile retaining wall using data measured in the field. The experimental results showed that the cross-sectional force and displacement of the high-strength bonded pile retaining wall were reduced by 13.6~19.7%, the shear force increased by 0.7~4.7%, and the bending moment increased by 4.5~8.8% relative to the values for the C.I.P retaining wall. Examination of the amount of subsidence in the ground around the excavation showed that the maximum settlement of the C.I.P retaining wall was 46.89 mm and that at the high-strength combined buried pile retaining wall was 39.37 mm. Overall, designing a high-strength combined embedded pile retaining wall by applying the maximum bending moment and shear force calculated using the elastic beam method to the site ground was shown to achieve the safety of all members, as member forces were generated within the elastic region.

An Analysis of Flexural Performance of Concrete Filled Soldier Pile Applied to Temporary Retaining Wall (흙막이 벽체에 적용하는 콘크리트 충전형 엄지말뚝의 휨성능 분석)

  • Park, Yong-Hyeon;Kim, Do-Bumn;Ju, Young-Kyu;Yang, Il-Seung;Yom, Kyong-Soo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.3
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    • pp.19-25
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    • 2019
  • The purpose of this study was to evaluate bending performance of concrete filled soldier pile for temporary retaining wall. Structural performance tests were conducted on total number of four specimens. Each specimen had a unique characteristics with combination of the following variables, existence of reinforcing bar and locations of reinforcing steel plates. The results of this study were as follows; concrete filled steel tubes with being reinforced bar and flange rather than non-bar showed better performance. Higher yield, tensile strength and sufficient plastic strain were archived and maximum moment observed in experiments exceeded theoretical maximum moment in both allowable stress design and limit state design at all specimens.

An Experimental Study on the Inclined Earth Retaining Structure in Clay (점토지반내의 IER 지주식 흙막이의 실험적 고찰)

  • Jeong, Dong-Uk;Im, Jong-Chul;Yoo, Jae-Won;Seo, Min-Su;Koo, Young-Mo;Kim, Sung-Jin
    • Journal of the Korean Geotechnical Society
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    • v.29 no.6
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    • pp.63-75
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    • 2013
  • Inclined Earth Retaining Structure Method (IER Method), was developed in order to improve the mechanical properties of the existing earth retaining method. IER consists of two supports, which are front and back supports. In the IER method, back support is very effective for the reduction of the earth pressure acting on the front support. In this study, the effects of back support and fixing conditions of lower ends of supports are analysed by laboratory model tests in clay. The test results show that back support reduces the Leteral displacement of IER effectively, and according to the results the effect of interval and fixing condition of back support was analysed.

A Case Study on the Top-Down Methods Performed in the Excavation Works of Domestic Downtown (국내 도심지 굴착공사에 적용된 Top-Down 공법의 시공사례 연구)

  • Chung, Jeeseung;Park, Sukk
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.2
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    • pp.5-19
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    • 2017
  • Underground excavation for building construction in Korea is changing from conventional support method (Strut, Ground anchor) to inside permanent support method by stability, economic, circumstances around excavation and etc. This study was selected the sites of Top-down, New Top-down, S.P.S, S.T.D and B.R.D in general use. This study was compared and analyzed a construction cost and period between aforementioned methods and conventional support method. Also, this study was confirmed the stability of temporary retaining wall by analysis for measurement data under construction. As a result, this study can grasp that most improved permanent support method is excellent in economic and constructability than conventional support method in case of deep excavation and rapid appearance of bedrock.

Case Studies on Ground Improvement by High Pressure Jet Grouting(II) Effect on the Ground Reinforcement and Cut off of Ground Water Behind Temporary Retaining Walls (고압분사주입공법에 의한 지반개량사례연구(II) -흙막이벽 배면지반보강 및 차수효과)

  • Yun, Jung-Man;Hong, Won-Pyo;Jeong, Hyeong-Yong
    • Geotechnical Engineering
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    • v.12 no.5
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    • pp.5-16
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    • 1996
  • When braced excavation with temporary retaining wall installation, is performed in loose sand with high ground water level boiling may be induced and considerable damage on the excavation works and structures in the vicinity can take place. Recently, for the purpose of reinforcement of ground and cut-off of ground water behind the temporary retaining wall, high pressure jet grouting is widely used. The purpose of this paper is to investigate the effects of jet grouting on ground reinforcement and cut -off of the ground water behind temporary retaining walls for braced excavation. A series of both laboratory and field tests has been performed. The test results show that high pressure jet grouting has sufficient effects on reinforcement of stiffness of ground and retaining wall. The permeability of the improved ground was 10-f_ 10-3cm l s smaller than those of the original ground. Therefore, the effect on cut off of ground water behind temporary retaining walls could be improved by high pressure jet grouting method.

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