• Title/Summary/Keyword: Underground Works

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A study on the robot for mining of underground resources (지하자원 채굴용 로봇의 연구)

  • Noh, Jong-Ho;Shin, Suk-Shin;Park, Jong-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.4
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    • pp.399-403
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    • 2013
  • Mining diggers have been substituted with the robots for the mining works in dangerous and narrow tunnel, and those demands are increased in nowadays. In this study, experimental research on the remote controlled robots to perform after the development of the robot. According to the test results, performances of the developed robot and its working devices have been modified several times. It has been considered that the robot keeps its optimum performance in states as follows; driving speed 1.0 km/h, crawl angle $10^{\circ}$, spiking cycle 500bpm and breaking power $30kg_fm$. And also it has been found that sufficient cooling for the robot's working parts is essential to extend those working periods longer than 3 hours steadily under rating condition.

A study on the change of strength parameters reinforced rock bolt in the ground around tunnel (록볼트로 보강된 터널주변지반의 강도정수 변화에 대한 연구)

  • Kim, Sang-Hwan;Bang, Gyu-Min
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.7 no.1
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    • pp.51-61
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    • 2005
  • In general the strength parameter of the ground will be changed by reinforcing the ground around tunnel. In this case, the concept of tunnel design, such as supporting system, excavation, lining and so on, should be modified based on the failure criteria or the ground changed by the reinforcement. This paper presents the variation mechanism of strength parameters and new failure criteria of the reinforced ground. In order to perform this research, theoretical and experimental works were carried out. It was clearly founded that the cohesion of strength parameters is only increased by reinforcement of ground, especially by rock bolting.

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A Study on Risk Influence Factors of Ground Subsidence through Soil Investigation Analysis (지반조사 분석을 통한 지반함몰 위험영향인자 연구)

  • Joung, Ho Young;Lee, Gil Hwan
    • Journal of Korean Society of Disaster and Security
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    • v.10 no.1
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    • pp.43-46
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    • 2017
  • Recently, the development of underground space is being actively carried out in the urban area by saturation, and the excavation works are mainly carried out by various excavation methods by the structures adjacent to the ground and underground excavation. During such excavation work, ground subsidence accidents are occurring due to inattention construction, lack of construction technology, and leakage of ground water. For the prevention of ground subsidence we studied the method of risk influence factors by soil investigation. Analysis of 75 sites soil investigation by U.S.C.S (Unified Soil Classification System), construction method, depth of excavation and we studied the risk influence factors with ground subsidence.

Analysis of Behaviors of SPS Underground Composite Frames Considering the Rigidity of RC Wale-Steel Beam Joint (RC 띠장-철골 보 접합부의 고정도에 따른 SPS 지하복합골조 거동 해석)

  • Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.3
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    • pp.243-250
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    • 2004
  • In SPS system, steel beams are used as not only temporary struts supporting the wale but main flexural members of building. Previous experimental works show that RC wale-steel beam joints have some flexural rigidity. In this paper, nonlinear analysis is performed using DRAIN-2DX program to investigate the behaviors of the underground composite frames constructed with SPS system when the rigidity of RC wale-steel beam joints change. Analysis variables are the procedure of construction, magnitude of lateral forces, and flexural rigidity of the RC wale-steel beam joint with stud connector. Analysis results show the effects of joint rigidity for the yielding process of frame and the moment and deflection at the mid-span of beam.

Technical-Economical Evaluation of Chain Vertical Alignment in Underground Urban Subways: The Case of Qom Subway, Line A

  • Abdi Kordani, Ali;Mehrara Molan, Amirarsalan
    • International Journal of Railway
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    • v.7 no.2
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    • pp.35-39
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    • 2014
  • Urban subways are one of the main parts of urban transportation networks in every city that always requires much attention in order to improve its efficiency in aspects of safety, reliability speed and costs. As the viewpoint of costs, an accurate design, especially design of vertical alignment, can have a dominant role to reduce the costs of urban railway projects. This paper seeks to evaluate the advantages and disadvantages of designing chain vertical alignment for urban subways in compare to flat vertical alignment. To achieve this goal, line A of Qom subway in Iran was selected as a case study in this research. Five parameters considered in the technical-economical evaluation: (1) energy consumption, (2) rolling stock, (3) operation, (4) civil works and geotechnical and (5) hydrological, drainage and pumping. According to the results, a power saving of about 40% have been estimated in the chain vertical alignment for the train without regenerative braking in compare with the flat vertical alignment, although the power saving was calculated less than 10% for the train with regenerative braking. Finally it was found that due to the modern rolling stock technology, the chain vertical alignment represents fewer advantages in compare to the past years.

Model Test of Lining for Estimation of Tunnel Soundness (터널 건전도 평가를 위한 라이닝 모델실험)

  • Kim, Young Keun
    • Magazine of korean Tunnelling and Underground Space Association
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    • v.1 no.2
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    • pp.59-71
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    • 1999
  • Recently, many deformations in tunnel such as crack and leakage were occulted. Specially, the defects of tunnel lining have been a serious problem in safety and stability many repair works for maintenance in tunnel have been carried out. Therefore, it is necessary to estimate the structural cracking for countermeasure in deformed tunnel and to investigate on the characteristics of lining system and the soundness of tunnel. In this study model tests for tunnel lining were carried out using test apparatus and centrifuge, In the direct loading test, the prototype was Kyungbu high-speed railway tunnel and the scale is 1/10, and lining models were made of concrete. Test conditions included load conditions such as direction, shape and type, lining conditions such as single and double lining, thickness, and reinforcement. In centrifuge model test, the prototype was Seoul subway tunnel and the scale is 1/100, and lining models were made of aluminum and hydrostone. Test conditions included tunnel defects such as thickness shortage. behind cavity and longitudinal cracks, reinforcement methods such as epoxy, grouting and carbon sheet. From these model tests , the characteristics of deformation and failure for tunnel lining were estimated, and the structural behaviors of deformed lining and the effects of repair and reinforcement for tunnel lining were researched.

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Performance of an Duct-type HVAC System for Conservation of Ancient Tombs (고분보존용 덕트형 공조시스템의 운전 특성)

  • Jun, Yong-Du;Lee, Kum-Bae;Park, Jin-Yang;Ko, Seok-Bo;Jun, Hee-Ho;Youn, Young-Muk
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.29-34
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    • 2006
  • Although the importance of good conservation of historic sites including ancient royal tombs is well aware, still not much attention has been paid for the facilities and systems to preserve those historic sites, which includes precious artifacts as wall paints and carved works, etc. Even the level of general understanding about the environment of the underground space of tombs is not satisfactory. In Korea, researchers have recently begun addressing the importance of maintaining proper environment for underground space as of ancient tombs and are making efforts to develop suitable HVAC(heating, ventilating and air-conditioning) systems for them. In this study, an HVAC system for a tomb ($D{\times}W{\times}H=1.3m{\times}3.0m{\times}1.2m$) was installed to maintain suitable indoor conditions for conservation of tomb. The temperature and humidity inside the tomb were measured to represent the performance of the installed duct-type HVAC system. Vibration levels due to the installed an HVAC system are alive investigated experimentally. According to the measured data, the level of vibration inside the present model tomb with the duct-type unit showed significantly lower values than the case with the indoor unit inside.

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A study on the economical analysis of non-supporting form in basement wall cases (지하옹벽 무지주 거푸집 사례의 경제성 분석에 관한 연구)

  • Kim, Jae-Yeob;Kim, Gwang-Hee;Lee, Sang-Woo;Sohn, Young-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.111-117
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    • 2009
  • Considering the entire critical path, underground works in construction projects occupy a large part of the total construction period, as well as a large part of the construction costs. Particularly in the downtown area, the scale of underground work has been increasing every year. Currently, underground retaining walls, which are built at construction sites, require many skilled workers, and the works are being undertaken by means of the Euroform+Soldier system, which is quite disadvantageous in terms of the construction period. In order to complement this, forms made of new materials and new construction methods have been developed. Now more than eyer, the shortening of construction periods and the reduction of construction costs is required. Considering this, in this study, the researcher has tried to compare the Euroform+Soldier system, which has been the system most frequently used on construction sites, to the non-supporting form system, which has been used on the sites of civil engineering work. The results of the research revealed that although the Euroform+Soldier system was advantageous from the perspective of material costs, it was disadvantageous in terms of labor costs. It is thought that an additional study on a method for reducing the material costs is required, so as to revitalize the application of non-supporting forms to the construction site.

Hydrogeological Properties of Geological Elements in Geological Model around KURT (KURT 지역에서 지질모델 요소에 대한 수리지질특성)

  • Park, Kyung Woo;Kim, Kyung Su;Koh, Yong Kwon;Choi, Jong Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.3
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    • pp.199-208
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    • 2012
  • To develop site characterization technologies for a radioactive waste disposal research in KAERI, the geological and hydrogeological investigations have been carried out since 1997. In 2006, the KURT (KAERI Underground Research Tunnel) was constructed to study a solute migration, a microbiology and an engineered barrier system as well as deeply to understand geological environments in in-situ condition. This study is performed as one of the site characterization works around KURT. Several investigations such as a lineament analysis, a borehole/tunnel survey, a geophyscial survey and logging in borehole, were used to construct the geological model. As a result, the geological model is constructed, which includes the lithological model and geo-structural model in this study. Moreover, from the results of the in-situ hydraulic tests, the hydrogeological properties of elements in geological model were evaluated.

A Study on the Absorption of Thermal Stress on the Underground piping for the District heating (지역난방용 매설배관의 열응력 흡수에 관한 연구)

  • Kong Jae Hyang;Sin Byung Kug
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.1
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    • pp.81-88
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    • 2005
  • There have been many studies on generation equipment and plant piping, but there is no significant study result on the heat transportation pipe. As such, this study established basic theory on the compensated method among buried pipe for regional heating, and further obtained the following results by applying the conditions of AGFW and NCHPP respectively in calculation of friction and maximum installation distance for the buried pipe. Friction coefficient according to the types and physical properties of soil, friction and maximum installation distance were compared to set the application value of friction coefficient according to the location of works. Calculation formula of clay load to be applied for calculation of friction was introduced to the formula of AGFW and the formula of NCHPP that has been used in Nowon district since 1997 to determine the difference and applicability. $120^{\circ}C$ and $95^{\circ}C$ were applied in temperature difference for expansion volume to compare the arm length at the curve pipe so thai it can be reflected in the design in the future. Maximum installation distance according to thickness of pipe was compared to present the necessity of unified specification so that same kinds of pipe materials can be used for same kinds of works.