• Journal of Drive and Control
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• v.18 no.2
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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.

• The Journal of Engineering Geology
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• v.8 no.3
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• pp.225-234
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• 1998

The behavior of the underground opening depends mainly on the magnitude of the initial stress existing before excavation and on the stress redistribution due to the excavation. In the case of elasto-plastic materials such as rock mass, as the structural behavior of surrounded opening due to excavation depends on the stress path, methods and sequence of excavation have influences on the results of numerical analysis. Therefore, in order to design underground openings with large cross-section such as underground nuclear power plants, radioactive waste disposal cavems, oil storage caverns, and so on more reasonably it is desirable to consider the effect of the excavation sequence in the analysis. In this paper, the underground structure is analyzed using the finite element method and the distinct element methods with a view to review the the effect of the excavation sequence. Based on the results of the analysis the followings are discussed : influence of excavation shape and sequence, effect of structural reinforcements, influence of multi caverns.

• Tunnel and Underground Space
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• v.19 no.3
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• pp.167-173
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• 2009

Underground storage cavern is known as the most complicated underground project because of the complexity of construction schedule, tunnel size, and geological problems. In order to optimize the construction schedule of underground storage cavern, two up-to-date technologies were applied. The first technology was 3 dimensional visualization of complicated underground structures, and the second was 4 dimensional simulation considering construction resources, geological conditions and construction schedule. This application case shows that we can achieve optimized construction schedule in the ways to optimize the number of work teams, fleets, the sequence of tunnel excavation, the commencement time of excavation and the hauling route of materials and excavated rocks. 3 dimensional modeling can help designer being able to understand the status of complicated underground structures and to investigate the geological data in the exact 3 dimensional space. Moreover, using 4 dimensional simulation, designer is able to determine the bottle neck point which appear during hauling of excavated rocks and to investigate the daily fluctuation in cost.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.30-30
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• 2022

최근 기후변화로 인한 국지성 호우 빈도 및 강수량이 급증하는 등 극한강우 발생 가능성이 높아지고 있는 실정이다. 공공 기반의 유역 및 지자체별 침수 대응은 지속적으로 이루어지고 있으나, 건설 현장 대응은 이에 비해 미흡한 실정이다. 특히, 건설 현장의 경우, 예측할 수 없는 홍수 유출에 대해서도 기존 설계시 반영된 홍수 유출량과 기상청 정보에만 의존하고 있어 극한강우 발생시 취약성을 나타낼 수 있다. 특히, Top-down 현장은 개구부, 표면 작업을 위한 포장 등에 의해 지하부로 유입되는 강우량이 많고, 지하 굴착공사시 단차 및 지하수 발생으로 극한강우시 침수에 의한 수재해 발생 확률이 높다. 이를 대비하기 위해 XP-SWMM 모형을 이용하여 지상부와 지하부의 강우-유출량을 산정하고 지하부 침수를 모의하였다. 실제 Top-down 현장조사를 통해 침수 관련 인자와 XP-SWMM을 연계하여 침수모의 기법에 적용하였다. 관련 주요인자는 강우량, 현장 지상부 면적, 지상부 배수로, 지하 유입부, 지하 배수펌프 등으로 현장 조사결과 나타났다. 강우자료의 경우, 극한강우를 고려하기 위해 현장 지역의 최대 강우량, 태풍 루사와 기상청 강우의 증가 시나리오를 고려하여 모의에 적용하였다. 본 연구에서는 극한강우에 대한 Top-down 침수 모의를 수행할 수 있는 상용 모델링과 이와연관된 인자를 도출하여 침수 모의 기법을 최적화 하였다. 이러한 침수 모의를 통해 Top-Down 현장 침수심 등을 예측할 수 있다. 향후 이를 통해 지하공간이 있는 건설현장의 강우-유출 현상및 침수 모의가 가능하고, 실시간 현장별 침수 예측 모델 개발로 현장별 대피경로 및 대응방안을 제시하여 인적 피해를 최소화할 수 있을 것으로 기대할 수 있다.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.692-705
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• 2018

Ground vibration is one of the remarkable issues in tunnel blasting. In recent studies, to improve the fragmentation with reduction of ground vibration in tunnel blasting, a vibration-controlled blasting method with artificial cutting slot near the center-cut holes has been suggested. This study examines the effect of the different arrangement of artificial cut-slot on the vibration reduction and fragmentation by performing the full-scaled concrete block blast experiments and the numerical simulations with 3D-DFPA. The results show that the existence of artificial slot contributes to the improvement of vibration reduction, blast fragmentation and the efficiency of the cutting slot blast. It can be explained that the artificial slot play a free surface role and should decrease the burden between the cut holes. Crater volumes of the blasted concrete blocks were measured by 3-dimensional digital image analysis and compared with the ideal standard crater volume which can be calculated by theoretical standard blast design method. As a result, the ratio of burden and hole diameter which should achieve the standard crater in the cut-hole blasting were suggested.