• Title/Summary/Keyword: Earth construction

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New Key-Segment Closing Method Using Thermal Effect for Partially Earth-Anchored Cable-Stayed Bridges (온도 효과를 이용한 일부 타정식 사장교의 키-세그먼트 폐합법)

  • Won, Jeong Hun;Yoon, Ji Hyun;Cho, Kwang Il;Kim, Sang Hyo
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.121-129
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    • 2008
  • study proposes a new key-segment closing method using thermal effect as a substitute to the process of set-back and reset-back for the FCM construction of a partially earth-anchored cable-stayed bridge. The proposed method is to artificially heat up the inside of girders located in the main span before closing the key-segment in a cantilever state. Then, the heat is removed after finishing the closure in a continuous bridge state. Using the changes in boundary conditions and structural systems, the proposed method can generate new member forces that reflect the advantage of the partially earth-anchored cable system. From the construction sequence analysis, it is found that the proposed method increases the efficiency of a partially earth-anchored cable-stayed bridge by reducing the compressive axial forces on the girders.

Analysis and Countermeasures for the Trouble Factors of the Spot Installation Pile Using Machine Excavation Method (기계굴착공법을 적용한 현장타설말뚝 시공시 부조화 발생요인 분석 및 대응 방안)

  • Park, Hong-Tae;Son, Chang-Baek
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.75-83
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    • 2009
  • Although a range of machine excavation methods are in wide use, including casing, earth drill and reverse circulation drilling, deterioration in pile quality and faulty construction can be often found these days because of trouble in the construction field. For this study, research was conducted in the form of a survey of construction engineers working in the field in order to identify the types and the causes of trouble by focusing on all casing, earth drilling and reverse circulation drilling. By analyzing the causes of trouble, countermeasures could be presented. The data and the analysts presented in this study could be effectively used for minimizing trouble in future machine excavation work during construction.

A Study on the Characteristics of Piling Vibration by SIP Method about Variation of Various Earth Conditions (지반조건의 변화에 따른 SIP 항타진동의 특성에 관한 실험적 연구)

  • Kwak, Kwang-Soo;Park, Jae-Young;Lee, Byeong-Yun;Kim, Jae-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.927-932
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    • 2000
  • Recently, construction vibration has caused annoyance for a number of dwellers in nearby construction field and that induced from operating of large construction equipment, has become a very serious issue in our living environment. But, construction vibration standard of our living environment. But construction vibration standard of our country is efficient. Especially, directly blow method(diesel piling method, oil pressure method, etc) has caused much problems of highly impactive vibration. Construction works, in order to solve these problem, will be used SIP(Soilcement Injected Precast Pile) method of low vibration equipment. In this point, this study attempts to survey on the characteristics of piling vibration by SIP method for various earth conditions in construction field. And this study intends to get the basic data to establish a standard about construction vibration.

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A study on the lateral Earth Pressure and Stress Relaxation Region According to the Infinitesimal Deformation of the Wall and Backside Earth Built by Non-excavation Method Under Railroad (철도하부 비개착공법의 벽면배면토사의 미소변형에 따른 수평토압 및 응력이완영역에 관한 연구)

  • Park, Yoon-Sik;Lee, Jun-Seok;Cho, Kook-Hwan
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2393-2399
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    • 2011
  • In the case where the bottom of railroad is penetrated by non-excavation construction method, the design is performed based on the assumption that there is no displacement and no change of stress However, measurement data showed that reduction of earth pressure and relaxation of stress take place by the displacement. In this study, we investigated the earth pressure on the structure under the railroad constructed by a non-excavation method and the stress relaxation region. The design based on earth pressure is non-economical because it is an over design. Relaxation of stress may lead to road base settlement and rail irregularly due to the reduced railroad supporting stiffness, to ballast crack in the case of concrete roadbed. The result showed that it is reasonable to set the stress on the structures as active earth pressure not as earth pressure at rest. Additionally, the study on the stress relaxation region identified the regions that should be supported in future construction by a non-excavation method.

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Design Case Study of Permanent Excavation Wall Using Soil Nailing System (쏘일네일링 공법을 적용한 영구 지하굴착 벽체의 설계사례 연구)

  • Park, Si-Sam;Lee, Je-Man;Yoo, Chan-Ho;Kim, Hong-Taek
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.84-91
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    • 2005
  • In case of soil nailing system, there have been many attempts to expand into slope and temporary earth retaining system stabilization method since the first ground excavation earth retaining system construction in 1993. Recently, jointing wall, underground wall of buildings and excavation earth retaining wall, construction were increasingly applied for effective utilization of the limited underground space and land application maximized. However, the application of joining wall into retaining wall or building by temporary soil nailing system and design of permanent wall were performed by using Rankine earth pressure theory without considering the distribution of earth pressure in the soil nailing. In this study was performed to introduce the design case by 'Two-Body Translation mechanism (TBTM)' to be able to consider distribution of earth pressure in the soil nailing when designing the permanent jointing wall using soil nailing system for effective utilization of ground space. Also, this study attempts to evaluate the earth pressure change, decreasing effect of wall displacement and increasing effect of stability when advanced soil nailing system is constructed using $FLAC^{2D}$ ${\nu}er.$ 3.30 program and 'Two-Body Translation mechanism'.

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Stability Evaluation of Earth Retaining Structure using Tower Truss System (새로운 무지보 흙막이 공법의 안정성 평가)

  • Kim, Young-Seok;Kim, Ju-Hyong;Kim, Young-Nam;Kim, Seong-Hwan;Lee, Sung-Reol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1324-1329
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    • 2009
  • Needs for underground space development and utilization have been increasing in urban area. The conventional strutting method in excavation is effective to restrain the ground movements and displacements of earth structures but inefficient for workers because of small working space. The conventional earth reinforcement methods such as earth-anchor and soil-nailing also have limitation to apply in urban area due to threats to stability of adjacent buildings around excavation boundaries. Recently, many types of earth retaining structures are being developed to overcome disadvantages of conventional excavation methods in urban area. In this study, a series of numerical analyses were performed with MIDAS GTS, geotechnical analysis program and MIDAS Civil, structural analysis design program to evaluate behavior and stability of the new type of non-supporting earth retaining structure, called Temporary Tower System (TTS), consisting of tower truss structures with much economical and spatial advantage.

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A Case Study on the Discrete Segmental Retaining Wall in Highway Construction (분리형 보강토공법의 고속도로 적용사례)

  • 노한성;최영철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10a
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    • pp.337-344
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    • 2001
  • The application of mechanically stabilized earth wall(MSEW) with segmental front panel has been increasing in highway construction due to its cost-effectiveness. However, some failures during construction have been reported and many field engineers are reluctant to select this method for important structure. One of the main reasons may be that there is no moderate specification for design and construction of MSEW yet. This paper discussed the main results of analysis on a case of block-type segmental retaining wall in highway construction. Based on the results, some recommendations on design and construction method of MSEW are presented.

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A Study on the Selection Model of Retaining Wall Methods Using Case-Based Reasoning (사례기반추론을 이용한 흙막이공법 선정모델에 관한 연구)

  • Kim Jae-Yeob;Park U-Yeol;Kim Gwang-Hee;Kim Joong-Koo
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.5 s.21
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    • pp.76-83
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    • 2004
  • There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. However, a frequent change order during construction happens in Korea where different performers design and construct separately, so there is a great possibility for the change order to affect the aspects of construction cost and period which normally define the outcome of construction work. Therefore, the study has suggested the rational retaining wall method by developing the case-based reasoning model as stool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. Applying the 'CBR Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining work.

A Simple Method for Predicting Lateral Earth Pressure in Consideration of Construction Speed of Embankment (성토 재하속도를 고려한 측방토압의 간이예측법)

  • Im, Eun-Sang;Kim, Hyoung-Soo;Kim, Tae-Hoon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1055-1060
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    • 2005
  • In evaluating the stability of underground structures and designing prevention methods against the lateral flow, it is necessary to predict the amount and the distribution of the lateral earth pressure acting on these retaining structures. However, because the lateral deformation of real ground is a very complex phenomenon influenced by interaction between volumetric deformation bringing an increase of stability of ground and shear deformation causing failure of ground, any appropriate methods for estimating the lateral earth pressure in consideration of the geotechnical properties of ground and the construction conditions in embankment have not been developed as yet. Therefore, a prediction method, which considers effects of a construction speed of embankment, using the Boussinesq's solution based on the elasticity theory without using complex numerical analyses such as finite element analyses is proposed in this research.

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A Study on Deformation of Soft Clay Foundation by Embankment Construction (제방축조에 의한 연약점토지반의 변형해석에 관한 연구)

  • 정형식;황영철
    • Geotechnical Engineering
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    • v.9 no.2
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    • pp.55-64
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    • 1993
  • When earth structures such as dykes or embankments are constructed on very soft clay foundation, unexpectedly large deformations of earth structures as well as clay foundation are encountered during and after construction. The final constructed section is composed of a portion of embankment above the existing ground level and that which penetrated into the soft foundation soil. This study is aimed to correctly estimate the shape of earth structures which penetrate some depth into the soft clay foundation. In this study the methods to predict penetration depth and deformation shape of embankment section after dumping of construction material. Model tests were carried out to prove the developed theory and FEM analysis. And when the mat is added, reinforcement effect was markedly noticed.

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