• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.1
• /
• pp.167-175
• /
• 2019

To effectively deal with the fire in tunnel which is mostly the vehicle fire, it's more important to suppress the fire at early stage. In urban tunnel, however, accessibility to the scene of fire by the fire fighter is very limited due to severe traffic congestion which causes the difficulty with firefighting activity in timely manner and such a problem would be further worsened in underground road (double-deck tunnel) which has been increasingly extended and deepened. In preparation for the disaster in Korea, the range of life safety facilities for installation is defined based on category of the extension and fire protection referring to risk hazard index which is determined depending on tunnel length and conditions, and particularly to directly deal with the tunnel fire, fire extinguisher, indoor hydrant and sprinkler are designated as the mandatory facilities depending on category. But such fire extinguishing installations are found inappropriate functionally and technically and thus the measure to improve the system needs to be taken. Particularly in a double-deck tunnel which accommodates the traffic in both directions within a single tunnel of which section is divided by intermediate slab, the facility or the system which functions more rapidly and effectively is more than important. This study, thus, is intended to supplement the problems with existing tunnel life safety system (fire extinguishing) and develop the remote-controlled automatic fire extinguishing system which is optimized for a double-deck tunnel. Consequently, the system considering low floor height and extended length as well as indoor hydrant for a wide range of use have been developed together with the performance verification and the process for commercialization before applying to the tunnel is underway now.

• Journal of the Korean Society for Railway
• /
• v.19 no.3
• /
• pp.380-387
• /
• 2016

Considering that the Seoul subway sector is expected to see extension of lines, addition of stations, and changes of operating companies, a review is needed to identify ways to eliminate or minimize financial deficits in its operation. As for deficits from the operation, additional businesses for extra income have been suggested as alternatives, but inasmuch as Western urban development (that of the subway containment area) may not be applicable to Korean settings, a practical alternative is to maximize income by efficient use of rental facilities that are located inside station properties. This alternative requires the estimation of appropriate facility size and rent for each station; few, however, have addressed this topic. At this juncture, this study aimed to draw an equation for estimating the sizes and rents of station properties by reflecting characteristics of lines and locations; a case study was performed for Subway Lines 5 and 6. Analytical findings are that rental facility sizes and rental incomes are affected mainly by the subway ridership and transport revenues, whereas the influence of ground-level commercial activity is relatively weak. A particularly great influence was found to be the value of apartment housing in areas through which the subway lines run. Stations on Line 5, which runs through areas of high-value housing, were assigned smaller facility sizes and higher rents than those on Line 6, which covers areas with relatively low housing value. The equation suggested in this study would make possible more practical feasibility studies when the need arises to estimate sales of new or extended facilities affiliated with stations.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.14 no.4
• /
• pp.385-410
• /
• 2016

The disposal facility in Gyeongju is planning to dispose of 800,000 packages of low- and intermediate- level radioactive waste. This facility will be developed as a complex disposal facility that has various types of disposal facilities and accompanying management. In this study, based on the comprehensive development plan of the disposal facility, a preliminary post-closure safety assessment is performed to predict the phase development of the total capacity for the 800,000 packages to be disposed of at the site. The results for each scenario meet the performance target of the disposal facility. The assessment revealed that there is a significant impact of the inventory of intermediate-level radionuclide waste on the safety evaluation. Due to this finding, we introduce a disposal limit value for intermediate-level radioactive waste. With stepwise development of safety case, this development plan will increase the safety of disposal facilities by reducing uncertainties within the future development of the underground silo disposal facilities.

• Journal of Digital Convergence
• /
• v.14 no.12
• /
• pp.405-411
• /
• 2016

Seoul city is publishing new plans to increase modal share rate of bicycle every year, such as, maintaining bicycle related facilities. But bicycle's modal share rate in Seoul stayed same for the last decade and people are still facing difficulties using bicycle related facilities. These problems are causing bicycle usage as connecting transportation of public transit to decrease. This study looked at the high bicycle modal countries, such as, Netherlands, Germany and Japan to find applicable solutions by analyzing cases and comparing them with cases of highly populated subway station of Sindorim in Seoul. For example, in Germany and Netherlands there is bicycle-parking system to help bikers to access subway easier, in Japan there is underground bicycle parking tower to safely keep high volume of bicycles with in small space. For Seoul city to increase its modal share rate, they should look at problems from users' prospective and solve it by fixing it and improving the services, not by making more facilities.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.3
• /
• pp.75-87
• /
• 2018

The purpose of this study is to investigate conservation and management methods of the Joseon Royal Tombs under the Eastern District Management Office. Through the literature survey, we understood the process of change of Joseon royal tombs, and through field surveys and interviews, we understood the status of the interior and the surrounding area. In this process, topography, land use and flow of human traffic, architecture and stone objects, water system, historical forests, and facilities were set as the main evaluation indicators. Urbanization has damaged the original terrains of Royal Tombs as national roads, buildings and facilities have constructed in the inner and outer area of Joseon Royal Tombs. Construction of underground passage, land purchase, relocation and demolition of the buildings are required for the conservation of the Royal Tombs area, and then it is necessary to recover the original terrain. In the case of land use and pathways, there are many disconnection of the original ritual circulation, they should be maintained to remind the sacred atmosphere of the royal tomb. And It is necessary to collect accurate information on the lost buildings and stoneworks through literature survey and excavation investigation, and that investigations should be lead to the exposure or restoration of the ruins. Historical forests require periodic and ongoing monitoring and management, and it is necessary to establish new entrance area and appropriate facilities following the long-Term conservation and management plan. These plans should be classified into short, medium and long-Term projects according to urgency and securing financial resources with a long perspective to implement continuous and systematic projects.

• Journal of the Korean GEO-environmental Society
• /
• v.19 no.10
• /
• pp.13-19
• /
• 2018

Following the 2016 Gyeongju earthquake, the Pohang Earthquake occurred in 2017, and the south-east region in Korea is under the threat of an earthquake. Especially, in the Pohang Earthquake, the liquefaction phenomenon occurred in the sedimentation area of the coast, and preparation of countermeasures is very important. The soil liquefaction can affect the underground facilities directly as well as various structures on the ground. Therefore, it is necessary to identify the liquefaction risk of facilities and the structures against the possible earthquakes and to prepare countermeasures to minimize them. In this study, we investigated the seismic liquefaction risk about the electric power utility tunnels in the southeast area where the earthquake occurred in Korea recently. In the analysis of seismic liquefaction risk, the earthquake with return period 1000 years and liquefaction potential index are used. The liquefaction risk analysis was conducted in two stages. In the first stage, the liquefaction risk was analyzed by calculating the liquefaction potential index using the ground survey data of the location of electric power utility tunnels in the southeast region. At that time, the seismic amplification in soil layer was considered by soil amplification factor according to the soil classification. In the second stage, the liquefaction risk analysis based on the site response analyses inputted 3 earthquake records were performed for the locations determined to be dangerous from the first step analysis, and the final liquefaction potential index was recalculated. In the analysis, the site investigation data were used from the National Geotechnical Information DB Center. Finally, it can be found that the proposed two stage assessments for liquefaction risk that the macro assessment of liquefaction risk for the underground facilities including the electric power utility tunnel in Korea is carried out at the first stage, and the second risk assessment is performed again with site response analysis for the dangerous regions of the first stage assessment is reasonable and effective.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.3
• /
• pp.46-59
• /
• 2023

Various Baekje ground-level building sites have been identified, in Pungnaptoseong Fortress, including Mirae Village's site E-1. However, building site E-1 is the only one with excavated roof tiles that are directly connected to the building site. As for building sites E-2, D-1, and D-2, which are comparable to site E-1, it is very possible that they had tiles on the roof based on their jeoksim (blocking facilities for roof slopes) and building structures. Also, although they are semi-underground pit structures, pit building sites A-30 and modern apartment site A-5, as well as the No.44 remains of Gyeongdang District, which is closer to a ground-level type, the buildings with tiles may have been constructed in the form of partial tile roofs rather than full-face tile roofs. Therefore, there may be several reasons behind the use of tiles on roofs in the early days, but the primary background of the building's authoritative function would have been considered first. Considering that China and Japan started using tiles on nationally important buildings such as palaces, temples, and ritual buildings, it may be presumed that Baekje began using tiles from the time it centralized power. It is believed that Baekje's early roof tile buildings evolved from rudimentary residential architecture to advanced public architecture, taking into consideration fire prevention and structural stability in large buildings. It is difficult to find similar cases in Korea with structural features such as the elevated foundations or underground stone foundations that can be found in Mirae Village building site E-1. Rather, similar architectural techniques can be found in China and Japan. In China, similar construction techniques were discovered in buildings of worship that were primarily built in the palace surroundings, such as Jangan Castle. Based on this, it appears that roof tile building sites, such as site E-1, that have been discovered have a strong correlation with the characteristics of buildings of worship, and ground type buildings, such as sites D-1 and D-2, are important facilities that are related to important public facilities such as state-run warehouses. This provides many implications regarding the early Baekje city structure.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.3
• /
• pp.543-560
• /
• 2018

With the increased development in downtown underground space facilities that vertically cross under a railway at a shallow depth, the demand for non-open cut method is increasing. However, most construction sites still adopt the pipe roof method, where medium and large diameter steel pipes are pressed in to form a roof, enabling excavation of the inside space. Among the many factors that influence the loosening region and loads that occur while pressing in steel pipes, the size of the pipe has the largest impact, and this factor may correspond to the magnitude of load applied to the underground structure inside the steel pipe roof. The super equilibrium method (SEM) has been developed to minimize ground disturbance and loosening load, and uses small diameter pipes of approximately 114 mm instead of conventional medium and large diameter pipes. This small diameter steel pipe is called an SEM pile. After SEM piles are pressed in and the grouting reinforcement is constructed, a crossing structure is pressed in by using a hydraulic jack without ground subsidence or heaving. The SEM pile, which plays the role of timbering, is a fore-poling pile of approximately 5 m length that prevents ground collapse and supports surface load during excavation of toe part. The loosening region should be adequately calculated to estimate the spacing and construction length of the piles and stiffness of members. In this paper, we conducted a comparative analysis of calculations of loosening load that occurs during the press-in of SEM pile to obtain an optimal design of SEM. We analyzed the influence of factors in main theoretical and empirical formulas applied for calculating loosening regions, and carried out FEM analysis to see an appropriate loosening load to the SEM pile. In order to estimate the soil loosening caused by actual SEM-pile indentation and excavation, a steel pipe indentation reduction model test was conducted. Soil subsidence and soil loosening were investigated quantitatively according to soil/steel pipe (H/D).

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.3
• /
• pp.421-435
• /
• 2017

Recently, due to the saturation of ground structures and the overpopulation of pipeline facilities requires to development of underground structures as an alternative to ground structures. Thus, mechanized tunnel construction of the shield TBM method has been increasing in order to prevent vibration and noise problems in construction of the NATM tunnel for the urban infrastructure construction. Tunnel construction plan for the tunnel line should be formed in a sharp curve to avoid building foundation and underground structures and it is inevitable to develop a shield TBM technology that suits the sharp curve tunnel construction. Therefore, this study is about the structural stability technology of the articulation jack, shield jack and skin plate for the shield TBM thrust in case of the mechanized tunnel construction that is a straight and sharp curve line. The construction case study and shield TBM operation principle are examined and analyzed by the theoretical approach. The torque of the cutter head, the thrust of the articulation jack and the shield jack, the amount of over cutting for curve is important respectively in shield TBM construction of straight and sharp curve line. In addition, it is very important to secure the stability of the skin plate structure to ensure the safety of the inside worker. This study examines the general structure and construction of the equipment, experimental simulation was carried out through numerical analysis to examine the main factors and structural stability of the skin plate structure. The structural stability of the skin plate was evaluated and optimizes the shape by comparing the loads of the articulation jack by selecting the virtual soil to be applied in a straight and sharp curve line construction. Since the present structure and operation method of the shield TBM type in domestic constructions are very similar, this study will help to develop the localized shield TBM technology for the new equipment and the vulnerability and stability review.

• Radiation Oncology Journal
• /
• v.23 no.4
• /
• pp.243-252
• /
• 2005

Purpose: Indoor air quality (IAQ) in the radiation treatment center which is generally located underground is important to the health of hospital workers and patients treated over a long period of time. this study was conducted to measure and analyze the factors related to IAQ and subjective symptoms of sick building syndrome, and to establish the causes influencing IAQ and find a solution to the problems. Methods and Materials : Self administrated questionnaire was conducted to check the workers' symptoms and understanding of the work environment. Based on a preliminary investigation, the factors related to IAQ such as temperature, humidity, fine particulate. carbon dioxide, carbon monoxide, formaldehyde, total volatile organic compounds (TVOC), and radon gas were selected and measured for a certain period of time in specific sites where hospital workers stay long in a day. And we also evaluated the surrounding environment and the efficiency of the ventilating system simultaneously, and measured the same factors at the first floor (outdoor) to compare with outdoor all quality, All collected data were assessed by the recommended standard for IAQ of the domestic and international environmental organizations. Results: Hospital workers were discontented with foul odors, humidity and particulate. They complained symptoms related to musculo-skeletal system, neurologic system, and mucosal-irritatation. Most of the factors were not greater than the recommended standard, but the level of TVOC was third or fourth times as much as the measuring level of some offices in the United States. The frequency and the amount of the ventilating system were adequate, however, the problem arising in the position of outdoor-air inlets and indoor-air outlets involved a risk of the indraft of contaminated air. A careful attention was a requirement in handling and keeping chemical substances including a developing solution which has a risk of TVOC emissions, and repositioning the ventilating system was needed to solve the contaminated-air circulation immediately Conclusion We verified that some IAQ-related factors and inadequate ventilating system could cause subjective symptoms in hospital workers. The evaluation of IAQ was surely needed to improve the underground working environments for hospital workers and patients. On the basis of these data, from now on, we should actively engage in designs of the department of radiation oncology or improvement in environments of the existing facilities.