• Title/Summary/Keyword: earth wall

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Study on the Development of Reinforced Earth Retaining Wall (보강옹벽개발연구)

  • 유용환
    • Geotechnical Engineering
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    • v.2 no.3
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    • pp.51-66
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    • 1986
  • The design of fabric reinforced retaining wall structure was discussed in this article. It was confirmed that the reinforced retaining earth wall which was designed by new theoretical formulae developed this time was stable structurally and economically. The plastic fabric filter which was placed in layers behind the facing element reduced the lateral earth pressure on the wall elements in comparison with a conventional retaining earth walls. The reinforcing characteristics of earth wall was governed by the spacing of fabric layers, effective length of fabrics, particle distribution and compaction, and thus it is essential that, in the construction field, the reinforcing strips should be selected in order to develop the maximum friction forces bet.eon soil and fabric filters. The maximum tensile stress developed from the reinforcing strips was appeared at a little far distance from the back of skin element and it was not well agreed with the Rankine's theory but distributed well as a symmetrical shape against the point of the maximum tensile stress. The total length of the different layers should be sufficient so that the tension in the fabric strip could be transferred to the backfill material. Also the total stability of reinforced earth wall should be checked with respect to a failure surface which extended blond the different lathers.

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A case study on reinforcement and design application of reinforced earth wall using micro pile (마이크로 파일을 이용한 블록식 보강토옹벽의 보강 및 설계적용 사례 연구)

  • Hong, Kikwon;Han, Jung-Geun;Lee, Kwang-Wu;Park, Jong-Beom
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.161-167
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    • 2014
  • This paper describes reinforcement method of reinforced earth wall near the abutment. The excessive displacement of a case affected by reduction of bearing capacity due to macro-environment condition like a coast. That is, the front displacement of reinforced earth wall has been happening continuously due to strength reduction of foundation ground. The micro pile is applied to reinforcement method, in order to secure a bearing capacity and global slope stability of reinforced earth wall. The results of numerical analysis confirmed that reinforcement method based on micro pile can secure a stability of structure, while the reconstruction of reinforced earth wall is impossible by construction and macro-environment condition.

A Study on Performance Improvement of a PHC-W Pile for PHC-W Retaining Wall (PHC-W 흙막이용 PHC-W말뚝의 성능개선에 관한 연구)

  • Kim, Chae Min;Kim, Sung Su;Jeon, Byeong Han;Choi, Yongkyu
    • Journal of the Korean Geotechnical Society
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    • v.33 no.2
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    • pp.27-34
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    • 2017
  • Various earth retaining wall methods were used on the domestic construction sites and a cast in place pile (C.I.P) method was mostly applied at deep excavation. Because of a lot of shortcomings in the C.I.P method, a new method using PHC-W earth retaining wall was developed. The earth retaining wall method using PHC-W piles has a lot of advantages including that it is safer than other earth retaining wall methods due to uniform quality and high rigidity. PHC-W was designed to effectively resist lateral earth pressure by alternating cross section of PHC pile. And increment of bending moment and shear strength were verified through KS F 4306 tests, and were increased by 42% and 98% more than KS standards.

An Fundamental Study on the Earth Wall Material Development by using of Lime Composition and Earth (석회복합체와 흙을 이용한 흙벽체 재료 개발에 관한 기초적 연구)

  • Hwang, Hey zoo;Kang, Nam Yi
    • KIEAE Journal
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    • v.10 no.5
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    • pp.115-121
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    • 2010
  • Lime was the solidifier mostly used at the fields of construction and civil works in the past. however, the development of Portland cement remarkably reduced the use of it. Recently as the concernment on circumstances gets higher, lime wined attention again as an eco-friendly material and was used at earth-using construction. This study examined the physical and chemical capacity of lime complexes with lime capacity improved, and performed fundamental study on the way to concretize by mixing it with earth. As a result, lime complex pressure strength was lower than cement pressure strength but it showed the possibility that its strength was improved by W/B control. The measurement of XRD after paste formation confirmed a compound generated by the reaction of Ca2+ion and Si, Al, and Fe from pozzolan reaction. A earth wall experiment by using lime complexes and earth showed that the higher, WB or the lower the quantity of unit combined materials, the lower the pressure strength was. The maximum pressure strength was maximum 11MPa when the quantity of unit combined materials was 450. It is because the composed earth particles had a high content of micro powder less than silt, so a lot of combination are demanded to secure fluidity. As a result of peptization experiment, after hardening, the material was not dissolved, which informed of the possibility of use as an outer subsidiary material. If the material is hardened by mold formation method, natural hardening crack appears. Cast expresses smart surface quality and enables to design for multiple purpose. The result shows the possibility of construction of low-story structures by using earth wall made of lime complexes and earth.

Effects of Relief Shelves on Stability of Retaining Walls

  • Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.9
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    • pp.25-31
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    • 2022
  • Attaching shelf to retaining structure leads to a decrease in the total lateral earth pressure. This decrease enables the retaining structures to become more stable, to have small displacement, and to exhibit lower bending moments, the relief shelves effects are analyzed using FEM in order to understand how they stabilize cantilever wall in this study. Several models are varied by changing location and width of shelves to realize earth pressure and displacements of retaining wall. The displacement is getting smaller because earth pressure acting on shelf increases as shelves locations are lower and width is longer. The ground settlement variation effects caused by relief shelves are studied also. The ground settlement increases abruptly where shelf location is between of 0.5H and 0.625H, and settlement decreases suddenly where shelf width is between b/h=0.375 and b/h=0.500. The shelf significantly reduces earth pressure and movement of the wall. This decrease in the lateral pressure increases the retaining structure stability.

Correlation between Strut Preloading and Earth Retaining Structures in Deep Excavations (깊은 굴착시 버팀대 선행하중과 흙막이 구조물과의 상호 관계)

  • 양구승;오성남
    • Journal of the Korean Geotechnical Society
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    • v.16 no.2
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    • pp.23-30
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    • 2000
  • The use of strut-preloading method is gradually increasing in braced excavations in Korea. And it is necessary to analyze the effects of strut preloading on the wall deflection, wall bending moment and strut axial force, etc. In this study, by using the analysis method of beams on elasto-plastic foundations, measured data and calculated results of 2 sites are compared and parametric studies of correlation between preloading and earth retaining structures in sandy soils are carried out in strut preloading application. As results, about 50%~75% of design strut load is effective as preloading force in considering the displacement and member forces of earth retaining structures. And the effective stiffiness of strut should be at least 25% of th ideal value in order to restrain the excessive increase of wall deflection and bending moments. As one of some methods to prevent excessive movements in braced excavation, to preload the strut is confirmed as more effective way than to increase the stiffiness of strut in braced wall, if the excessive axial force of strut due to preloading can be avoided.

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A Study on Securing safety through Behavior Analysis of Earth Retaining Wall (흙막이 가시설의 거동 분석을 통한 안정성 확보 방안에 관한 연구)

  • Kim, Kwang-Leyol;Kim, You-Seong;Kim, Seong-Soo
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.11-19
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    • 2013
  • Recently despite the development of analysis program and construction technologies, collapse at the many earth retaining wall construction site of the structure due to the economic and human damage has occurred. The results of geothechnical investigation studies field, it was found to differ from the results of the original design. There may be errors parameters calculated from the results of ground investigation in such a case. And it can be estimated that it is irrational to behavior analysis of the earth retaining wall were analyzed by utilizing the parameters. And in this study, parameters that affect the earth retaining wall the correlations were analyzed using elasto-plastic method. Analysis method was changed various parameters (cohesion, subgrade reaction coefficient, load condition) applied to the elasto-plastic method. And due to a change in the behavior of earth retaining wall materials were analyzed. As a result, the cohesion greatly affects the behavior of earth retaining wall materials in various parameters. For this reason, the results of the geothechnical investigation, confirmation of the actual ground is very important in the design of the earth retaining wall. And, calculating accurate and reasonable of the cohesion of the various parameters is very important.

Case Study on Application of PHC Pile to Earth Retaining and Retention Wall (옹벽겸용 흙막이벽으로 PHC말뚝의 적용 사례 연구)

  • Han, Jung-Geun;Hong, Ki-Kwon;Eo, Yun-Won;Kim, Sang-Kwi
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.37-44
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    • 2006
  • The construction of earth retaining wall and structure which get environmental element have to appling at the same time, then construction period and construction cost increase. These system which is presented to overcomes shortcoming and have function of earth retaining wall and retention wall at the same time. However, because existing method has limit excavation depth, the advanced design pattern more than existing method, rows of pile was applied. The workability and stability of applied design method are evaluated through analyze of construction case. The results confirmed that application design method can solve displacement of pile and limit excavation depth in existing earth retaining wall.

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Experimental study on the ground movement due to consecutive construction of retaining wall and underground space in cohesionless soil (사질토 지반에서 흙막이벽체-지하공간 연속 굴착에 따른 지반거동에 대한 실험적 연구)

  • Park, Jong-Deok;Yu, Jeong-Seon;Kim, Do-Youp;Lee, Seok-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.3
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    • pp.267-281
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    • 2015
  • The ground movement and changes in earth pressure due to the consecutive construction of retaining wall and underground space were studied experimentally. A soil tank having 160 cm in length and 120 cm in height, was manufactured to simulate the vertical excavation like retaining wall by using 10 separated right side walls and underground space excavation like tunnel by using 5 separated bottom walls. The variation of earth pressure and surface settlement were measured according to the excavation stages. The results showed that the decrease of earth pressure due to the wall movement can cause the increase of earth pressure of the neighboring walls proving the arching effect. Experiments simulating continuous construction sequence also identified arching effect, however only 50% of earth pressure was restored on the 10th right side wall due to the movement of 1st bottom side wall unusually.

Active Earth Pressure behind Rigid Retaining Wall Rotating about the Top (정점을 중심으로 회전하는 강성옹벽에 작용하는 주동토압)

  • 백규호;사공명
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.181-191
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    • 2004
  • For a rigid retaining wall with rough face, the magnitude and distribution of active earth pressure on the wall are affected by the shape of failure surface and arching effect developed in the backfill as well as internal friction angle of the backfill and wall friction angle. Therefore, the practical shape of failure surface and arching effect in the backfill must be considered to acquire accurate magnitude and non-linear distribution of active earth pressure acting on the rigid retaining wall. In this study, a new formulation for calculating the active earth pressure on a rough rigid retaining wall rotating about the top is proposed considering the practical shape of non-linear failure surface and arching effects. Accuracy of the proposed equation is checked through comparisons of calculations from the proposed equations with existing model test results. The comparisons show that the proposed equations produce satisfactory results.