• Tunnel and Underground Space
• /
• v.25 no.6
• /
• pp.505-514
• /
• 2015

In this study, a stabilizing equipment was developed to resolve the problems of existing stabilization construction method for contaminated soil. The field application and workability of the stabilizing equipment were verified through field demonstration tests and laboratory tests. The field application of the stabilizing equipment was identified through field demonstration tests. As a result of laboratory tests for field mixed soil, the mixing capability of stabilizer of the developed construction method was better than that of existing construction method.

• The Journal of Engineering Geology
• /
• v.19 no.3
• /
• pp.417-422
• /
• 2009

Tunnels that have recently been constructed are characterized by longer length than ever before and furthermore they frequently go through the ground area with poor conditions such as fractured zones. If ground strength is weak, plastic deformation of tunnel occurs, and occasionally a big fall may be brought about. Up to now, the construction work of tunneling has been executed as a sequential method placing the lining concrete after completion of excavation. Such a method requires a long time and much money to complete the tunnel. It is hard to ensure the stability of tunnel if tunnel is left undone for a long time after excavation in fracture zones or plastic grounds. For this reason, we tried to take simultaneous construction of tunnel excavation and lining concrete in order to not only shorten construction schedule but also stabilize the tunnel at the highly fractures zone as soon as possible. As preliminary consideration for simultaneous construction, in-situ tests are performed to calculate the isolation distance over which blasting vibration does not influence the strength of lining concrete. Improvement of ling form, placing method of concrete, ventilation using a dust collector, together with equipment arrangement, was made to assure the simultaneous construction work.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.6 no.3
• /
• pp.227-235
• /
• 2004

Tunneling in rock mass produces two types of damages in the vicinity of a tunnel: structural and constructional damages. Structural damage represents the damage induced by the unbalance of geostatic stress caused by the tunneling, and constructional damage is the damage produced during the construction. In this study, formulations of tangential and radial stresses in the elastic and plastic zones near a tunnel, and the calculation of radius of plastic zone surrounding a tunnel are introduced by modifying the Hoek-Brown criterion of 2002 edition, which has capability of considering in situ rock mass characteristics and construction damage. From the parametric study, influences of rock mass quality, uniaxial compressive strength of intact rock, and the dimension of the tunnel on the plastic zone are investigated. The accuracy of the proposed approach is evaluated by comparing with results from the previous study.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.1
• /
• pp.129-134
• /
• 2011

The construction method in electrical room with hydro power generation is well informed in drawings and according to this method, to master the actual working conditions. It's necessary to consult location of KEPCO liability threshold with the KEPCO side, therefore make a decision to install the underground cable in hydro power station in each state, including outdoor pipes and manholes. Undulating rigid polyethylene conduit (125C) and CNCV-W extra high cable are laid and installed, to make a closely analysis to the construction by reviewing its process. In this work, the key part of the KEPCO power system for House of Commons is actually based on liability threshold, even including outdoors pipeline construction, high voltage underground electrical wiring and switchgear installation. It directly reveals the contents of the proposed construction methods about Housing Corporation and the High Voltage Switchgear Installation Inlet.

• Journal of Korea Society of Industrial Information Systems
• /
• v.14 no.5
• /
• pp.91-101
• /
• 2009

This study's purpose is to revive pre-construction situation earlier than construction of media facade using light-emitting diode, and analyze the strong and weak points of simulation image making process and technology, including lots of expressing methods. Exterior building decoration that was originated from Super Graphic led to the LED construction with a trend of increased night activities of these days. Initial Super Graphic was just in the level of deciding what to do with simple CAD drawings, but today's media facade construction is not so simple as the previous ones. This is because of the problems that should think about balances between neighboring environment and buildings, including high construction costs. According to survey results, media facade construction simulation's various expressing methods, its processes of analysis, and its strong & weak points will suggest standards for its size of construction and simulation purpose, including recommending suggestions that can respond rapidly by clients' diverse demands.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.47-47
• /
• 2010

배전계통의 사고예방 기술은 전력수요 및 증설이 증가하고 있는 상황에서 시급히 확립되어야 한다. 특히 현장에서 시공되는 케이블은 시공과정의 관리가 쉽지 않을 뿐 아니라, 시공 중 발생될 수 있는 결함들을 검출하는 방법도 제한되어 있다. 본 연구에서는 국내에 도입된 진단방법을 통계적 방법으로 분석하고 효과적으로 점검할 수 있는 방법에 관한 검토하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.742-745
• /
• 2010

본 논문은 초고층구조물의 해석방법으로 탄성변형과 아울러 시간의존성을 가진 크리프와 건조수축에 의한 비탄성변형을 고려한 비선형 시공단계 해석법을 제시한다. 기존의 초고층구조물 해석에서 주로 행하는 기둥 축소량 해석은 실무자의 경험과 프로그램을 통한 간략화에 맞추어져 있다. 이는 실제 시공 시 발생하는 구조해석 요소들을 충분히 반영하지 못하여 계산 값과 실제 값 사이에 오차가 발생된다. 비선형 시공단계 해석은 실제 시공 때 발생되는 해석변수들을 고려한 단계별 해석의 수행이 가능하며, 시간의 의존성을 가진 creep과 shrinkage의 효과를 함께 고려하여 일괄해석의 문제점을 구조해석 단계에서 실제상황에 가까운 해석을 가능하게 할 수 있다. 이를 위해 시공단계해석이 가능한 범용 프로그램을 이용한 50층 규모의 3차원 골조 프레임 모델 예제 해석을 통하여 기존 해석법들과의 비교, 분석으로 시간의 의존성을 고려한 시공단계해석의 필요성을 제시한다. 본 논문에는 범용프로그램인 SAP2000(ver.14)와 CEB-FIP모델 코드를 사용 하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.507-510
• /
• 2006

Recently, the skyscrapers are increasing. There are major cost-increasing factors to management in the skyscraper construction. The more projects are large like the skyscraper construction, the more systematic methods and tools are needed for cost control. This study proposes an assessment model for major cost-increasing factors in skyscraper construction using FMEA.

• Magazine of the Korea Concrete Institute
• /
• v.6 no.3
• /
• pp.152-161
• /
• 1994

Most widened bridges have been constructed by the joining-construction method that makes new and existing bridges structurally a single structure. Since the joining-construction method has several problems in design and construction viewpoint, this study is conducted in order to investigate the structural behaviors of RC slabs, which are widened and influenced by traffic-induced vibration of existing bridge during placing and curing of new concrete, with the prototype flexural strength test and FEM analysis. It was found that cracks are generated in construction joint at low applied load and that stress concentration at the joints and slips between steel bar and concrete are occured. But, the decreasing of load carrying capacity is negligible according to the traffic-induced vibration as well as the difference of construction method.

• Journal of the Korean Geotechnical Society
• /
• v.32 no.5
• /
• pp.15-26
• /
• 2016

Dam and embankment are very important civil structures. Grouting is widely used to repair and maintain dam and embankment, and it is important to evaluate the effect of grouting for dam safety. The non-destructive method based on determination of wave velocity in the dam or embankment is effectively used to evaluate grouting effect because wave velocity is identical with stiffness and grouting increases local stiffness in a dam. In this paper, HWAW (Harmonic wavelet analysis of waves) method was applied to evaluate the grouting effect. HWAW method can determine two-dimensional shear wave velocity map with good spatial resolution and the shear velocity profile by the proposed method is sensitive to a variation of stiffness of target system. Through numerical simulation and field tests, the applicability of HWAW method in determining grouting effect is shown.