• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.113-132
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• 1999

Recently in Korea, application of the soil nailing is gradually extended to the sites of excavations and slopes having various ground conditions and field characteristics. Design of the soil nailing is generally carried out in two steps, The First step is to examine the minimum safety factor against a sliding of the reinforced nailed-soil mass based on the limit equilibrium approach, and the second step is to check the maximum displacement expected to occur at facing using the numerical analysis technique. However, design parameters related to the soil nailing system are so various that a reliable design method considering interrelationships between these design parameters is continuously necessary. Additionally, taking into account the anisotropic characteristics of in-situ grounds, disturbances in collecting the soil samples and errors in measurements, a systematic analysis of the field measurement data as well as a rational technique of the optimum design is required to improve with respect to economical efficiency. As a part of these purposes, in the present study, a procedure for the optimum design of a soil nailing excavation wall system is proposed. Focusing on a minimization of the expenses in construction, the optimum design procedure is formulated based on the genetic algorithm. Neural network theory is further adopted in predicting the maximum horizontal displacement at a shotcrete facing. Using the proposed procedure, various effects of relevant design parameters are also analyzed. Finally, an optimized design section is compared with the existing design section at the excavation site being constructed, in order to verify a validity of the proposed procedure.

• 보존과학연구
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• s.7
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• pp.278-291
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• 1986

In this report the practical case of Viking ship's conservation in Denmarke specially among the Eurpoean nations is introduced. The contents of it are summarized as follows :From 1957 to 1962 the Danish National Museum Salvaged five Viking ships from the bottom of Roskilde Fjord, Which were composed of the pieces of timber whose surface was soft because they had lain on the sea bed for about a thousand years. Excavation had been carried out in the same way as in the field by driving down a sheet piling around the wrecks and pumping the water out. These pieces of the wreck ships were packed in airtight plastic bags one by one to be transported for Brede and then immidiately had to go through the treatment for conservation. The conservation treatment process for the pieces includes three steps ; the preliminary process prior to the hardening treatment, the hardening and the assemble of the ships. In the first step ; the preliminary process, all remains of mud and shells from the fjord bed are washed off, and measuring followed ; every single piece of wreckage was drawn so that the form and size of the piece, nail holes, and breaks were registered before conservation. In the second ; the hardening treatment step, the pieces of the woreckage were filled with P.E.G. This Polyethylene Glycol method was the best to handle in the subsequent mounting of the ships in the museum. In the final, the Glycol-treated pieces were pieced together to spips with support of a system of reinforcements. They were to fit in place after corrections of the form were made several times.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.607-614
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• 2014

The need for integration of knowledge and technology among SMEs has been acknowledged, and lacks ways of convergence in practical education. Therefore contents of convergence in practical education of high quality are needed. In this study, a case-oriented curriculum and contents were developed to enhance employee's skills of SMEs. The curriculum consists of 3 steps. The first step is analysis of trends and current status of convergence of SMEs in the domestic and foreign areas. Thus drawing up measures of standards to analyze a successful case. The second step is collection of materials, and development of models through successful cases of convergence. The third step is the analysis of a curriculum to enhance employees' of SMEs and the development of an education program. This study may lead to strengthening competition of SMEs through knowledge and technology convergence based on developed curriculum.

• Korean Journal of Oriental Medicine
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• v.8 no.2 s.9
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• pp.47-65
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• 2002

This project is planned to grasp the present situation of traditional medicine part in our country and to study protection method about this by the intellectual property which is the international concerning point recently. Through this, we will be able to devise means to deal with protection method of traditional medicine being developed by WIPO now. Traditional medicine field In our country Is organized with specific condition separated into the part of institution and the part of non-institution. So, because of the closed peculiarity, we have experienced the difficulties to understand the real facts about traditional medicine. We cannot be indifferent to the matter anymore. Because the expectation of object people is high, we could expect the realization of research content. In 1 detail project, we investigated the situation of traditional medicine in our country through various collecting methods for excavation of oriental treatment technique and herb medicine which is worth protecting. With it, we sorted again into 56 kinds of 11 parts through analysis of validity in the way of oriental medicine. And we tried to link this up 2 detail project which is about legal and institutional guarantee concerning protection. furthermore, we tried to find approach ways for security of objectivity into 4 steps with the example of model disease. we could complete practical classification of traditional medicine in our country. In 2 detail project, we studied the protection method by the intellectual property through research result in 1 detail project. For this, we observed an outline of the intellectual property including a patent application analysis in folk traditional medicine part, and problems of traditional medicine protection and world trend by traditional knowledge protection tendency and the patent law In domestic traditional medicines, the aspects unprotectable with the patent law now were remained. So, we suggested supplementary plan. And we also suggested the freedom of utilization between traditional medicine possession countries (in-situ utilization) and the demand compensation payment for a third country (ex-situ utilization) in connection with international movement.

• Tunnel and Underground Space
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• v.27 no.2
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• pp.109-119
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• 2017

A lot of twin tunnels were modelled with different pillar widths, rock mass classes and stress ratios in order to consider various site conditions, and the stabilities of the pillars were estimated by numerical analyses and scaled model tests. The strength-stress ratios of the pillar were obtained from three different methods which were using the stresses appeared at the middle point, the whole average and the left/right edges of the pillar. The strength-stress ratio of the pillar edges showed relatively conservative values among them, and it was also practically consistent with the tunnel excavating steps comprising the construction sequence analyses which included the partial excavation and the support system. Scaled model tests were also performed to investigate the tunnel stability, where it was found that cracks were progressively generated from the pillar edges toward the middle point of the pillar. Therefore, in order to both prevent the local damage of pillar and conservatively estimate the tunnel stability, it was thought to be an appropriate method using the strength-stress ratio obtained from the left/right edges of the pillar.

• Journal of Conservation Science
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• v.32 no.4
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• pp.449-457
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• 2016

A stoneware bottle was recovered from the Incheon Yeongheungdo Shipwreck in 2013. Primary observations showed that this object had a sealed opening and was covered with a foreign material. After it was cleaned via mechanical and chemical methods, wave patterns were observed on the outer surface of the bottle and a yellowish-brown transparent material was found within. In this paper, the process of conserving the stoneware bottle and the analysis conducted on the unknown material found within is explained. The conservation process included steps such as cleaning, desalination and restoration. After of the missing area located at the rim, the original shape of the bottle was made clear. In addition, the unknown inner material was analyzed using FT-IR and GC-MS. Results showed that the material is similar to golden lacquer. It is speculated that the Yeongheungdo Ship had wrecked during the Unified Silla period while carrying a bottle loaded with golden lacquer.

• Geomechanics and Engineering
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• v.27 no.6
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• pp.561-571
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• 2021

Cofferdams made of teel sheet piles are commonly utilized as support structures for excavation of sea-crossing bridge foundations. As cofferdams are often subject to tide variation, it is imperative to consider potential effects of tide on stability and serviceability of sheet piles, particularly, ultralong steel sheet piles (USSPs). In this study, a real USSP cofferdam constructed using new construction technology in Nanxi River was reported. The design of key parts of USSP cofferdam in the presence of tidal action was first introduced followed by the description of entire construction technology and associated monitoring results. Subsequently, a three-dimensional finite-element model corresponding to all construction steps was established to back-analyze measured deflection of USSPs. Finally, a series of parametric studies was carried out to investigate effects of tide level, soil parameters, support stiffness and construction sequence on lateral deflection of USSPs. Monitoring results indicate that the maximum deflection during construction occurred near the riverbed. In addition, measured stress of USSPs showed that stability of USSP cofferdam strengthened as construction stages proceeded. Moreover, the numerical back-analysis demonstrated that the USSP cofferdam fulfilled the safety requirements for construction under tidal action. The maximum deflection of USSPs subject to high tide was only 13.57 mm at a depth of -4 m. Sensitivity analyses results showed that the design of USSP cofferdam system must be further improved for construction in cohesionless soils. Furthermore, the 5th strut level before concreting played an indispensable role in controlling lateral deflection of USSPs. It was also observed that pumping out water before concreting base slab could greatly simplify and benefit construction program. On the other hand, the simplification in construction procedures could induce seepage inside the cofferdam, which additionally increased the deflection of USSPs by 10 mm on average.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.5
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• pp.459-470
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• 2014

Now-a-days, the trend in constructing tunnels is to build more deeper, more longer tunnels of greater cross-sections. That's why, the demand of "Early-high-strength shotcrete" is very high because of their advantage of attaining higher strength immediately after excavation, which controls the ground subsidence. So, this study reveals the supporting phenomena of early-high-strength shotcrete, using three-dimensional numerical analysis. The crux of this study can be applied practically in construction sites also. Support Performance of two different qualities of shotcrete was checked out, by keeping the general shotcrete's thickness constant and comparing it with early-high-strength shotcrete's thickness decreasing it gradually in five steps, and analysing/comparing the support performance in all cases. Effect of using early-high-strength shotcrete was analysed to save the cost of steel sets, which are widely used for supporting the ground before the hardening of general shotcrete. The results of numerical analysis on the performance of early-high-strength shotcrete show that, it behaves more effectively under worse ground conditions and it can support the ground more conveniently than steel sets, before the shotcrete is hardened.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.551-564
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• 2016

Earthworks are the fundamental steps in a construction job, and are mainly comprised of smaller tasks performed by construction machinery. The productivity of the construction job can be improved by optimizing excavation, filling, and other such operations. Earthworks involve a lot of mechanical work performed by the collaboration between various kinds of construction equipment, which in turn leads to higher fuel consumption. Actual earthworks depend mostly on the intuition and experience of the driver of the machines, thus leading to inefficiency and environmental problems caused by unnecessary emission of carbon, Recently automated and information-oriented technologies are consistently being researched towards the improvement of efficiency of earthworks in the construction industry. The present research involves the introduction and understanding of the decision-making elements of heuristics which can be applied to the earthwork planning. A method is also suggested for creating an effective work path for construction machine to perform task packages (TP) for cutting and filling processes. A simulation test is performed to verify the effectiveness of suggested methods in terms of space interference and total moving distance of construction equipment.

• Spatial Information Research
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• v.22 no.3
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• pp.79-87
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• 2014

In order to foster rapid disaster response and public life protection, National Emergency Management Agency has been trying to spread 'Emergency Rescue Standard System' on a national scale since 2006. The agency has also intensified management of firefighter's safety on disaster site by implementing danger predication training, specialized training and education and safety procedure check as a part of safety management officer duties. Nevertheless, there are limitations for effective fire fighting steps, such as damage spreading and life damage due to unawareness of illegal converted structure, structure transformation by high temperature and nearby hazardous material storage as well as extemporary situation handling endangered firefighter's life. In order to eliminate these limitations there is a need for an effort and technology application to minimize human errors such as inaccurate situational awareness, wrong decision built on experience and judgment of field commander and firefighters. The purpose of this study is to propose a new disaster response model which is applied with geospatial information. we executed spatial contextual awareness map analysis using fire-fighting vulnerable zone model to propose the new disaster response model and also examined a case study for Dalseo-gu in Daegu Metropolitan City. Finally, we also suggested operational concept of new proposed model on a national scale.