• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.379-379
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• 2022

기후변화로 인해 집중호우, 돌발 홍수 및 태풍의 규모가 대형화되고 있고, 이에 따른 수재해 피해 사례도 증가하는 추세이다. 특히 건설 현장 중 굴착공사 현장에서의 침수로 인한 사고는 인명피해로 이어질 가능성이 더 크기 때문에 더욱 주의가 필요하다. 하지만 현재 국내에서 실질적으로 굴착현장에 적용하기 위한 침수 대응 예측 시스템 및 구체적인 침수 예경보 체계, 기준, 매뉴얼은 존재하지 않는 실정이다. 따라서 본 연구에서는 굴착공사현장의 수재해 예방을 위한 침수 예·경보 시스템의 적용방안을 제시하였다. 또한 경제적이고 효과적인 측면을 고려하여, 공사현장 규모에 따라 적용하는 침수 예·경보 시스템을 이분화하여 소규모 공사현장에는 Track A, 대규모 공사현장에는 Track B 침수 예·경보 시스템을 적용하도록 제안하였다. 이러한 이유는 소규모 공사현장의 특성상 전체 공사비가 작고 운영되는 장비와 인력이 제한적이므로 침수 예·경보에 필요한 비용과 인력 투입이 어려울 수 있기 때문이며, 또한 대피가 필요한 전체 인원이 대규모 현장에 비해서는 적기 때문에 비교적 신속하고 원활한 대피가 가능할 것이라고 판단하였기 때문이다. 본 연구에서는 각 시스템별 적절하다고 판단되는 예·경보 기준을 제시하였다. Track A에서는 강우법에 의한 최소한의 경보시스템으로 필요한 안전목표를 달성할 수 있도록 고려하였고, Track B에서는 현장인원 대부분이 성인 남성임을 고려하여, 성인 남성의 부상을 유발할 수 있는 수심(H)과 유속(V)의 곱을 척도로 하는 한계 H·V곡선을 기준으로 운영되는 경보시스템을 제안하였다.

• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.11-17
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• 2011

The purpose of this study is 3 dimensional modeling of lower part of drilling system in offshore rig and simulation of drilling process. Recently, shipbuilding companies have been focusing on offshore rigs due to their high added-value and the reduced demand of new shipbuilding. In most cases, however, the basic design, installation and management of offshore rig are carried out by foreign companies. Therefore, it is difficult to obtain the knowledge and information of drilling system. In this study drilling devices, BOP(Blowout Preventor) and cementing job and mud circulation related components are included as the main components of offshore rig. The structure and function of them were analyzed from a viewpoint of object-oriented technique. On the basis of this analysis they were modeled in the 3 dimensional structure with 3D software tool such as CATIA and 3DVIA Composer. The drilling process was simulated according to the scenario of drilling operation. This simulation system can be effectively used for an educational tool for students and engineers in ocean plant industries.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.849-860
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• 2019

This paper is a study on the development of equipment system to obtain data on stability in excavation of sharp curve section of Shield TBM. Shield TBM equipment is being used a lot recently for tunnel excavation. Excavation may result in inevitable detours by buildings above the ground or existing underground structures. Preconstruction simulation is required to verify the stability of the construction in case of this. Therefore, it is necessary to establish an automated control system through the development of this equipment system and conduct simulation through simulation of excavation model in the sharp curve section. A system shall be developed to control the left and right angles and thrust of the equipment, and to view data on the earth pressure and propulsion pressure of the equipment in real time during excavation. With this system, the necessary data can be collected for field testing through excavation method and excavation simulation by angle. It is expected that it will be very useful in assessing the actual Shield TBM by conducting a scale-down model experiment.

• Journal of the Korean Geosynthetics Society
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• v.11 no.4
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• pp.45-53
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• 2012

Ground drilling is a common method to conduct site investigation, soil improvement, and pile installation. In the point of construction ground drilling requires electrical energy to drill a hole in ground in which the energy exerts into the motor located on the head of auger and generates rotational power. In this paper it is verified that the exerted electrical energy is closely related to the strength characteristics of ground. Measurement sensors, recording system, and drilling system were developed to obtain exerted motor current and drilling depth and laboratory soil box tests were carried out. The measured motor current and boring depth were applied to predict SPT N-value and the prediction results were compared to SPT N-value of laboratory tests. The test results show that the exerted electrical energy to bore ground be a good index to estimate SPT N-value.

• Journal of the KSME
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• v.52 no.11
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• pp.43-47
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• 2012

이 글에서는 두산인프라코어(주)를 중심으로 15개 국내외 기관이 참여하여 토목 및 전자 그리고 기계기술의 융합을 통해 개발한 세계 최초의 지능형 무인 굴착 시스템을 소개하고자 한다.

• Journal of the Korean Geotechnical Society
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• v.22 no.12
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• pp.77-88
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• 2006

A series of model tests were performed to investigate the ground deformation during trench excavation for diaphragm walls. An apparatus was manufactured to observe the failure pattern of a slurry-supported trench in sandy ground. Ground deformations including settlement and lateral displacement of the surrounding ground adjacent to the trench were carefully monitored during excavation. Experimental observations indicated that the settlement of the adjacent ground increased with closing to the trench. Especially, the considerable settlement occurred at the distance which was equal to 40% of the excavation depth. And, the higher settlement was obtained when the relative density of ground was looser and the ground water table was higher. Also, the lateral wall face of excavated trench was bulged with lowering the slurry level In stages and then the upper part of trench failed finally. The envelope of ground surface settlement could be represented as a hyperbolic line and the measured settlement was smaller than those predicted by Clough and O'Rourke (1990).

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.559-575
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• 2021

Due to the increase in ground excavation work, the possibility of ground subsidence accidents is increasing. And it is very difficult to prevent these risk fundamentally through institutional reinforcement such as the special law for underground safety management. As for the various cases of urban ground excavation practice, the ground subsidence behavior characteristics which is predicted using various information before excavation showed a considerable difference that could not be ignored compared to the results real construction data. Changes in site conditions such as seasonal differences in design and construction period, changes in construction methods depending on the site conditions and long-term construction suspension due to various reasons could be considered as the main causes. As the countermeasures, the safety management system through various construction information is introduced, but there is still no suitable system which can predict the effect of excavation and risk assessment. In this study, a web-based system was developed in order to predict the degree of impact on the ground subsidence and surrounding structures in advance before ground excavation and evaluate the risk in the design and construction of urban ground excavation projects. A system was built using time series analysis technique that can predict the current and future behavior characteristics such as ground water level and settlement based on past field construction records with field monitoring data. It was presented as a geotechnical data visualization (GDV) technology for risk reduction and disaster management based on web-based system, Using this newly developed web-based assessment system, it is possible to predict ground excavation impact prediction and risk assessment.

• Explosives and Blasting
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• v.24 no.2
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• pp.9-22
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• 2006

In general, tunnel construction except for special cases such as very short tunnels must require an artificial ventilation system. Especially, it is efficient for long tunnels to use the combination of a proper ventilation system according to the progress of the excavation. Neung-Dong Tunnel of which length is 4,580m has been originally designed as using ventilation system of blower and exhaust mixture types. Since it has been expected to result in some problems, its design Is analyzed to find the way to improve ventilation system by estimating the amount of required fresh air, considering various ventilation mixture types, ventilation's fluidity analysis and contaminant's distribution by numerical analysis. Economical efficiency for each type is also reviewed to determine the best ventilation system.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.719-730
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• 2021

An improved packer and injection system was developed to improve the efficiency of excavation by hydraulic rock splitting by reducing vibration and noise. Field testing of the system found hydraulic fractures limited in expansion and extension due to the loss of injection pressure by leackage from the cracks, and then the single packer applied to injection hole allowed to produce a sufficient tensile displacement for rock excavation. Numerical analysis based on the field test data could explain the development of cracks in the field experiments.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.5
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• pp.357-371
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• 2023

In cable tunnel construction using TBM, the vertical shaft is an essential structure for entrance and exit of TBM equipment and power lines. Since a shaft penetrates the ground vertically, it often encounters rock mass. Blasting or rock splitting methods, which are mainly used to the rock excavation, cause public complaints due to the noise, vibration and road occupation. Therefore, mechanical excavation using vertical shaft excavation machine are considered as an alternative to the conventional methods. However, at the current level of technology, the vertical excavation machine has limitation in its performance when applied for high strength rock with a compressive strength of more than 120 MPa. In this study, the potential utilization of waterjet technology as an excavation assistance method was investigated to improve mechanical excavation performance in the hard rock formations. Rock cutting experiments were conducted to verify the cutting performance of the abrasive waterjet. Based on the experimental result, it was found that ensuring excavation performance with respect to changing in ground conditions can be achieved by adjusting waterjet parameters such as standoff distance, traverse speed and water pressure. In addition, based on the relationship between excavation performance, uniaxial compressive strength and RQD, it was suggested that excavation performance could be improved by artificially creating joints using the abrasive waterjet. It is expected that these research results can be utilized as fundamental data for the introduction of vertical shaft excavation machines in the future.