• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.43-50
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• 2020

In this study, the possibility of seismic performance design was proposed and the quality verification test method was reviewed as part of the design of waterproof performance in underground walls under accelerated environment conditions for waterproofing materials, which are barrier and finishing material that can prevent ingress or overflowing water from inside and outside of a building by attaching all of the construction materials used in construction structures. Considering the current state of earthquake-resistant design of construction materials in Korea and abroad, seismic product groups are rare and mostly dependent on construction methods because there are no regulations on materials, although there are still regulations on earthquake-resistant design in the building process under the current law. Overseas, it was possible to confirm that various building materials that gave seismic performance to non-structural materials, such as Japan, Canada, and Germany, are being developed. If it is possible to have a complementary response to earthquakes in the advanced external waterproofing materials, it can be expected to be applicable as leak prevention and prevention technology along with the seismic designed structure.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.402-403
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• 2003

Garment manufacture represents the final stage of processing a finished fabric. The main task of the garment manufacturer is to produce shell structures out of flat fabrics to match the shape of the human body, and the most acceptable means of joining textile materials for apparel use is by sewing. On the sewing process, the bottom layer is pushed forward by the feed-dog, but the presser foot tends to retard the passage of the top layer. Since the friction between the layers is low, is possible that the components will move out of phase and pucker. (omitted)

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.217-223
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• 1999

Mostly, water leakage took place in construction joints. In case of cable tunnels constructed by open-cut method, waterstops have been used to prevent the water leakage. But, we haven't any experience to install the waterstops in NATM cable tunnels. So, it is necessary to develope the waterstops and test the performance of it in laboratory. We manufactured cable tunnel lining quarter scale model by pouring concrete, and installed the waterstops. After filling the inside of concrete lining about two-third with water, we put the air pressure on the water, In addition, it is also carried out water leakage test for concrete lining model without waterstops. As a result, we confirmed the performance of waterstops and its adaptability. It is also tested that the performance of rubber gaskets used in concrete segments of Shield tunnelling. In addition, we determined the allowable infiltration rate for cable tunnel with non-drainage system.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.03a
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• pp.49-58
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• 1993

Reappraisal of the design and the construction concept of the bottom drainage tunnel has been made through the seepage analysis. An appropriate design approach for this tunnel has also been proposed. It was revealed from this study that water pressures acting on the concrete lining in the bottom dralnage tunnel much depend on the permeability of the surrounding ground, the source of water supply and the discharge capacity of dralnage facilities. The full release of these water pressures by the current drainage system could not be expected if this type of tunnel is constructed in the ground including alluvial deposits having a high permeability. The necessity of a proper reinforcement of the concrete lining or a modification of its shapes corresponding to the water pressure has been suggested.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.299-307
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• 2009

New lake dike in Saemanguem area is 125km length and require a great amount of fill materials, but it's difficult to get the amount of materials and develop a quarry because of environment conservation. Therefore, the solution is to use the dredged soil in project area as the fill materials not to develop quarry. However, characteristic of dredged soil as a silty fined sand is very weak at seepage, sliding, erosion of dike due to infiltration of rainfall, wind etc. So, lake dike using dredged soil must be constructed safely against the unstable problem of dredged sand. The objective of research is to make safe lake dike using dereged soil on construction of Saemangeum new lake dike. So, we analyzed the characteristic of dredged soil and suggested a standard section of lake dike.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.42-45
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• 2003

Polyurethane(PU) products are generally used in the automobile, paint, furniture, adhesive, the medical and textile industries. Recently, the increasing acceptance of waterborne polyurethane (WBPU) Is motivated by more stringent environmental requirements, such as the reduction of solvent emissions into the atmosphere [1]. The application for textiles includes suede processing, soft-hand processing, wrinkle-free processing, antistatic processing, sizing and adhesives. (omitted)

• Tunnel and Underground Space
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• v.28 no.3
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• pp.258-276
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• 2018

The accurate and quantitative ground information on the hydraulic conductivity characteristics of rock mass is one of the key factors for evaluation of the hydro-geological behaviour of rock mass around an excavated opening under high water pressure. For tunnel and rock structures in seabed, where the sea acts as an infinite source of water, its importance become greater with increasing construction depth below sea level. In this study, to improve the problems related with poor system configuration and incorrect data acquisition of previous hydraulic packer testing equipment, we newly developed an integrated main frame and 30 bar level waterproof downhole sonde apparatus, which were optimized for deep hydraulic packer test in seabed rock mass. Integration of individual test equipment into one frame allows safe and efficient field testing work on a narrow offshore drilling platform. For the integrated type main frame, it is possible to make precise stepwise control of downhole net injection pressure at intervals of $2.0kg_f/cm^2$ or less with dual hydraulic oil volume controller. To ensure the system performance and the operational stability of the prototype mainframe and downhole sonde apparatus, the field feasibility tests were completed in two research boreholes, and using the developed apparatus, the REV(Representative Elementary Volume) scale deep hydraulic packer tests were successfully carried out at a borehole located in the basalt region, Jeju. In this paper, the characteristics of the new testing apparatus are briefly introduced and also some results from the laboratory and in-situ performance tests are shown.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.631-641
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• 2014

Characteristics of water-level changes in the Temporary Gulpocheon Discharge Channel were identified by observing and analyzing changes in the subterranean water level induced by hydrological stresses the underground aquifer. The subterranean water level refers to the level at which the pressure of subterranean water passing through the corresponding position has an equipotential value that is in equilibrium with the atmospheric pressure at that location. This water level is not fixed but changes in response to hydrological stress. It can be identified by repeatedly measuring the distance from the observation point to the surface of the subterranean water. The subterranean water-level change equation and the variance range of the hydrological curve of subterranean water over 24 hours at the Gimpo-Gimpo National Groundwater Monitoring Network (NGMN) were used as assessment factors. The variance characteristics of the subterranean water at the 18 monitoring system locations were classified into three impact, observational wish, and non-impact. The impact type accounted for 50% of the subterranean water of and accurately reflected the water-level changes due to hydrological stress, showing that distance is the major controlling factor. The observational wish type accounted for 27.8% of the subterranean water, and one of the two assessment factors did not meet the assessment factors. The nonimpact type accounted for 22.2% of the subterranean water. This type satisfied the two assessment factors and represents subterranean water-level changes response to precipitation.

• Tunnel and Underground Space
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• v.28 no.1
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• pp.97-110
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• 2018

The application of sprayed waterproofing membrane with high adhesion and ductility is considered to be promising as a measure for repair and reinforcement of a tunnel structure. Therefore, a powder-type and one-component membrane prototype with high tensile and bond strengths was made in this study. Then, its reinforcement effect on a shield segment was evaluated by carrying out a series of full-scale loading tests of segment specimens on which the membrane was sprayed. From the tests, it was confirmed that the initial cracking loads increased by approximately 34% due to cracking retardation by membrane coating. Even though the increase of failure loads were not so high as cracking loads, the strain-softening behaviors were observed from specimens coated by the membrane. Therefore, it is expected that the membrane coated on the inner surface of a lining might be effective in preventing its brittle failure.

• Tunnel and Underground Space
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• v.4 no.1
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• pp.24-30
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• 1994

Although a dry-system tunnel is not good for reasons fo economy and construction, it has been applied to some tunnels under construction owing to the advantages of good long-term maintenance of tunnel, prevention of consolidation settlement due to the drawdown of groundwater, preservation of the ecosystem, cutailment of operation cost, and so on. The stability of groundwater and the change of the applied water pressure after water proofing were analysed by the finite element method. Using this result, an example of designing the secondary lining for the dry-system tunnel which is to be constructed in low-permeability hard rock was presented.