• 드라이브 ㆍ 컨트롤
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• 제18권2호
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• pp.20-31
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• 2021

An excavator is a construction machine that can perform various tasks such as trenching, piping, excavating, slope cutting, grading, and rock demolishing. In the 2010s, unmanned construction equipment using ICT technology was continuously developed. In this paper, the path design process was studied to implement the output data of the decision stage, and the path design algorithm was developed. For example, the output data of the decision stage were terrain data around the excavator, excavator mechanism information, excavator hydraulic information, the position and posture of the bucket at key points, the speed of the desired bucket path, and the required excavation volume. The result of the path design was the movement of the hydraulic cylinder, boom arm, bucket, and bucket edge. The core functions of the path design algorithm are the function of avoiding impact during the excavation process, the function to calculate the excavation depth that satisfies the required excavation volume, and the function that allows the bucket to pass through the main points of the excavation process while maintaining the speed of the desired path. In particular, in the process of developing the last function, the node tracking method expressed in the path design table was newly developed. The path design algorithm was verified as this path design satisfied the JCMAS H02 requirement.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.248-259
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• 2010

In the case of relatively good ground and construction condition in the deep excavation for the construction of subway, railway, building etc., flexible earth retaining systems are often used in an economical point of view. It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system is done or change of ground condition is faced due to the construction conditions during construction process, lots of axial force can be induced in some struts and that can threaten the safety of construction. This paper introduces one example of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, the measured data obtained during construction process, were analysed, the effects of relatively deeper excavation than the specification on one excavation side and rapid drawdown of ground water level on the other excavation side were deeply investigated from the viewpoint of mutual influences between ground deformations of both excavation sides and strut axial force changes. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• 한국기계가공학회지
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• 제18권4호
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• pp.48-55
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• 2019

With recent rapid increases in the power generation capacity of offshore wind power generators, reliable structural analysis of the large-scale infrastructure needed to install wind power generators at sea is required. Therefore, technology for heavy marine equipment such as barges and excavation equipment is needed. Under submarine conditions, rock drilling technology to install the substructure for offshore wind pile excavation is a very important factor in supporting a wind farm safely under dynamic loads over periods of at least 20 years. After investigating the marine environment and on-site ground excavation for the Saemangeum offshore wind farm, in this study we suggest.

• 터널과지하공간
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• 제7권1호
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• pp.1-12
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• 1997

Engineering rock mass classification is extensively used to determine the reasonable support system throughout the tunneling process in the field. Selection of support system based on the results of engineering rock mass classification is simple and straight-forward. However, this method cannot consider the effect of in-situ stresses, mechanical properties of support material, and support installation time on the behavior or rock-support system To handle the various conditions encountered in the underground excavation sites rock-support system. To handle the various conditions encountered in th eunderground excavation sites rock-support interaction program has been developed. This program can analyze the interaction between rock mass and support materials and also can simulate the tunnel excavation-support insstallation process by controlling the support installation time and the stiffness of support system. Practical applicability of this program was verfied by comparing the results of support design to those from rock mass classification for virtual underground excavation at the drilling site KD-06 in Geoje island.

• 터널과지하공간
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• 제5권4호
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• pp.347-362
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• 1995

The purpose of this study was that manage effectively the excavation process of the transport tunnel in DONGHAE mine area by investigating the variationof the surface and groundwater flow system around the tunnel and neighbouring villages. Thus, the effect of excavation and water-prrofing process on the water system has been studied through the naked eye survey of the tunnel and the surface outcrop, joint survey, core drilling, the measurement of the surface water quantity, evapotranspiration and precipitation analysis, rock hydraulics approach, the pressure test of boreholes, the variation of the water level, and finally the numerical analysis. From above approachs, we derived the conclusion that the exhaustion of the surface water was not caused by the tunnel excavation on the groundwater system was minimized by effective water proofing process.

• Geomechanics and Engineering
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• 제35권5호
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• pp.525-538
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• 2023

The development of a city is closely linked to the construction and operation of its subway system. However, constructing a new subway tunnel under an existing station is an extremely complex task, and the deformation characteristics and mechanical behavior of the new subway tunnel during the excavation process can greatly impact the normal operation of the existing station. Although the previous studies about the case of underpass engineering have been carried out, there is limited research on the condition of a newly-built subway tunnel that closely undercrossing an existing station with zero distance between them. Therefore, this study analyzes the deformation law and mechanical behavior characteristics of the preliminary lining of the underpass tunnel during the excavation process based on the real engineering case of Chengdu Metro Line 8. This study also makes an in-depth comparison of the influence of different excavation methods on this issue. Finally, the accuracy of numerical simulation is verified by comparing it with on-site result. The results indicate that the maximum bending moment mainly occurs at the floor slab of the preliminary lining, while that of the ceiling is small. The stress state at the ceiling position is less affected by the construction process of the pilot tunnel. Compared to the all-in-one excavation method, although the process of partial excavation method is more complicated, the deformation of preliminary lining caused by it is basically less than the upper limit value of the standard, while that of the all-in-one excavation method is beyond standard requirements.

• 대한안전경영과학회지
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• 제21권4호
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• pp.31-37
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• 2019

When the foundation work of the underground part of the building structure or the excavation work of the civil engineering structure is carried out, there is the earthwork work by the inevitable process. As the economic situation continues to develop, construction in urban areas is becoming bigger and higher in scale due to the expansion of infrastructure and the rescue of urban dwellings in urban areas, and excavation of underground roads is inevitable. Excavation of the underground part may cause problems in the process difficulty and safety of the earthworks due to the complexity and various characteristics of the ground selected without consideration of the ground characteristics and site conditions. In order to complete the required facilities, it is necessary to secure the design and construction of the retaining walls. In order to complete the required construction, It is an important factor satisfying construction period and economical efficiency.

• 한국지구과학회지
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• 제37권3호
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• pp.143-161
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• 2016

본 연구는 발자국 및 보행렬 화석의 발굴 방법과 이의 적용에 관한 것이다. 공룡, 익룡 및 새 발자국과 같은 척추동물의 발자국과 보행렬 화석들은 공룡 등과 같은 실체 화석들과는 달리 일반적으로 특정 방향을 향하여 길게 진행한 흔적을 남기거나 넓은 층리면에서 발견되며, 평면적인(2차원적인) 특성을 가진다. 이와 같은 발자국 화석의 특성을 반영하여 비교적 넓은 층리면에 보존된 발자국 화석을 발굴하기 위해 새로운 방법을 고안하였고, 이 방법을 5곳의 발자국 화석 발굴 현장에 적용하였다. 그 결과, 발자국 화석산지에서 공룡, 익룡, 새 발자국과 보행렬 화석들을 성공적으로 발굴하였다. 그리고 다양한 발굴 사례에 근거하여, 발자국 화석 발굴의 단계별 과정과 세부 사항을 제안하였다.

• 헤리티지:역사와 과학
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• 제53권3호
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• pp.4-23
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• 2020

이 글에서는 문화재 발굴과 연구를 연결된 하나의 과정(process)으로 설정하고 그 개선 방안을 고찰하였다. 이를 위해 과정 통합의 관점에서 문화재 발굴 과정을 살펴 문제점을 진단하고 그 개선 방안으로 보고서의 형식 변화와 데이터베이스 구축을 제시하였으며 이를 통해 신라 고분 발굴과 연구의 개선 모델을 그려보았다. 현재 문화재 발굴 과정의 문제점을 지적하면 다음과 같다. 첫째, 조사와 연구가 일원화되지 못하고 '행정 절차로서의 조사' 혹은 '조사를 위한 조사'에 그치며 이는 궁극적으로 연구성과 달성에 걸림돌이 되고 있다. 둘째, 조사자 또는 기관마다 보고서의 구성이나 서술 방식에 차이가 있어, 보다 상위 차원에서 자료를 통합하고자 할 때 어려움이 있다. 셋째, 현재 보고 자료의 형태가 책이나 PDF 등의 아날로그에 머물고 있어 연구 단계로의 연속성과 효율성이 떨어질 뿐만 아니라 급변하는 시대의 변화에 뒤처지고 있다. 이러한 문제의 개선 방안은 보고서를 전산화하여 디지털 형태로 전환하고 이를 데이터베이스로 구축해야 한다고 보았다. 첫째, 보고서 형식의 전환은 발굴 과정에서 마지막 단계인 발굴 자료의 형태가 아날로그에 머물고 있다는 점을 지적하고 이를 발굴과 연구를 하나로 연결하는 관점에서 개선 모델을 제시하였으며 다른 사례와의 비교를 통해 그 당위성을 강조하였다. 둘째, 데이터베이스는 신라 고분을 대상으로 구축 모델을 검토하였다. 이를 위해 다른 분야의 사례를 살피고 목적과 기대 효과, 대상, 추진, 속성과 범주, 인터페이스를 고찰하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.87-92
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• 2000

In excavation of tunnels especially located in shallow depth, it is not rare to meet geological change in excavation progress worse than expected in the initial design stage. This paper present a case study on the re-design of excavation and support system of a shallow tunnel under construction where it meets the unexpected bad geological condition during excavation. The detailed geological investigation shows that the rock mass is heavily weathered and fractured with RMR value less than 20. Considering this geological condition, the design concept is focused on the reinforcement of the ground preceding the excavation of tunnel. Two design patterns, LW-grouting & forepoling with pilot tunnelling method and the steel pipe reinforced grouting method, are suggested. Numerical analysis by FLAC shows that these two patterns give the tunnel and roof ground stable in excavation process while the original design causes severe failure zone around the tunnel and floor heaving. In point of the mechanical stability and the degree of construction, the steel pipe reinforced grouting technique proved to be good for the reinforcement of heavily fractured rock mass in tunnelling. This assessment and design process would be a guide in the construction of tunnels in heavily weathered and fractured rock mass situation.