• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.43-59
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• 2002

In this study, database systems which were used to select the waterproof method according to leakage patterns of underground structures were built by performing pilot tests, reviewing literatures, and analysing the gathered data statistically. The database was built by using check lists which consisted of 5 major items and 73 subdivided items, and 26 major parameters according to 4 classified grades were determined on the base of survey which considered various in-situ conditions. The database of waterproof methods was comprised of 10 methods which were applied in Korea. From the database of waterproof methods, application ranges and design conditions of waterproof methods were suggested. From the results of study, database system consists of parameters selection database, waterproof method database, and design condition database. From the results of pilot tests, when the database of waterproof methods was applied to design stage, saving time and reducing mistakes for selecting waterproof method were gained. In addition, when the database of waterproof methods was applied to construction stage, effects such as evaluation of applicability of waterproof method, improvement of constructability and post management were expected.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.669-683
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• 2017

The objective of this study is to propose a modification of the previously proposed drainage system for catching the partial leakage of underground concrete structures. Two techniques were proposed for applying the drainage system only to the leaking parts. One was for conveying leaking groundwater to the collection point in the drainage system and the other was for conveying the collected groundwater to the primary drainage system of the underground concrete structure. Four waterproofing materials for conveying leaking groundwater to the catchment point of the drainage system, Durkflex made of porous rubber material, KE-45 silicone adhesive with super strong adhesion, Hotty-gel made of polymeric materials and general silicone adhesive were evaluated for waterproofing performance. Hotty-gel only showed perfect waterproof performance and the other three waterproof materials leaked. The modified drainage system with Hotty-gel and drainage pipe with fixed saddle to convey the leaking groundwater from the catchment point to the primary drainage system were tested on the concrete retaining wall. The waterproof performance and the drainage performance were evaluated by injecting 1,000 ml of water in the back of the modified drainage system at the 7-day, 14-day, 21-day, 28-day, 2-month and 3-month. There was no problem in waterproof performance and drainage performance of the modified drainage system during 3 months. In order to evaluate the construction period and construction cost of the modified drainage system, it was compared with the existing leaching repair method in surface cleaning stage, leakage treatment stage, and protective barrier stage. Total construction period and construction cost were compared in considering the contents of work, repair material, construction equipment, working time, and total number of workers. As a result of comparing and analyzing in each construction stage, it was concluded that the modified drainage system could save construction period and construction cost compared to the existing leaching repair method.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.514-523
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• 2019

Purpose: This study was designed to provide necessary institutional improvements for job security for foreign workers in the domestic construction sector. Method: I analyzed the National Statistical Office and related reports to investigate the status of foreign workers. Based on this, the government came up with measures to improve the system. Results: Based on the current comparative advantage index (RCA) analysis, the technology standard of foreign workers compared to Korean workers was evaluated, and the results were analyzed in order of moldwork, rebar, concrete work, stone work, and waterproof work. Conclusion: A foreign worker's work system was introduced to solve the problem of local Lunar New Year's Day field manpower. To ensure stable implementation of the system, there is a need to improve the operation of the employment permit system at construction sites and limit the size of the construction industry that introduces the employment permit system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.379-387
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• 2016

In this study, a survey was conducted on the required measurement and waterproofing performance for residential building underground structure leakage prevention system. According to the results of the survey, it has been determined that leakage problem is considered to be quite severe, and many respondents have agreed. The legal guidelines and regulation systems do not reflect properly on the environmental requirements or conditions, resulting in continued leakage problem. In regards to this, a standardized waterproofing technique that can be used in underground areas of residential structures is required as an obligation and the development of high performance waterproofing method that allows for wet concrete surface adhesion and a guideline, design and maintenance method that allows the control of overall situational control of leakage is required.

• Tunnel and Underground Space
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• v.27 no.6
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• pp.343-350
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• 2017

Amid increasingly saturated ground space, development of underground space has been booming throughout the world and excavation has been underway near the structure above or under the ground level. But the ground subsidence caused by improper or poor construction technologies, underground water leakage, sudden changes of stratum and the problem with earth retaining system component has been emerged as hot social issue. To deal with such problems nationwide, establishment of preventive and proactive disaster management and rapid restoration system has been pushed now. In this study, collection of the data on technology development trend to secure the underground safety was made, taking into account of internal change elements (changing groundwater level, damage to underground utilities, etc) and external change elements (vehicle load, earthquake and ground excavation, etc) during excavation. Amid the growing need of ground behavior analysis, ground subsidence evaluation technology, safe excavation to prevent ground subsidence and reinforcement technology, improvement of rapid restoration technology in preparation for ground subsidence and development of independent capability, this study is intended to introduce the technology development in a bid to prevent the ground subsidence during excavation. It's categorized into prediction/evaluation technology, complex detect technology, waterproof reinforcement technology, rapid restoration technology and excavation technology which, in part, has been in process now.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.123-134
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• 2009

Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.8-16
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• 2004

The industrialization of central Europe more than 100 ago marked the beginning of densely concentrated buildings in quickly growing cities. A cheap type of roofing material of that time was tar. But it was dangerous because it was high inflammable. Then some roofer had a splendid idea. They used sandy material as a final layer atop the impermeable tar layer. These roofs were much more fire resistant than the typical roofs. In this sandy layer some plant species began to grow spontaneously. This was the beginning of the green roof history of modern Europe. A number of these green roofs survived both world wars. In the early 80's in Berlin alone, 50 such buildings existed and they continued to be waterproof until the present day. Since the 1992 Earth Summit of 1992 in Rio de Janeiro(http://www.johannesburgsummit.org/html/basic_info/unced.html) the term "sustainable development" became of central interest of urban designers. In city regions green roofs had become synonymous with this term. With a small investment, long-lasting roofs can be created. Further back in history, more exciting examples of green roofs can be found. The hanging gardens of antiquity are well-known. There are also green roofs built as insulation against cold and heat all over the world. For over 20 years, roof greening in central Europe has been closely examined for various reasons. Roof greening touches several different disciplines. Of primary interest is the durability of the roofs. But ecologists are also interested in green roofs, for instance in biodiversity research. The beneficial effect of greening on water proofing was also proven. For some time, the issue of fire protection was investigated. According to tests, green roofs received a harsh careful rating. Their fire protective property is considered similar to that of tile roofs. Another recent impulse for the green roof movement in Germany has come from the evident improvement of storm water retention and the reduced burden on the sewer system. The question of whether and how much energy green roofs can save has become an urgent question. The state of the research and also various open questions from a central European point of view will be discussed in the context of international collaboration. Apart from academic considerations, those who involve themselves in this issue take a predominantly positive view of the numerous existing green roofs in Germany. In some cities, green roofs are the typical construction technique for new buildings. A few outstanding examples will conclude this review. In Germany, about 20 companies, some of which operate internationally, specialize in green roof consulting. Learning from each other in an open-ended way with respect to different construction techniques and applications in various climatic regions can only be accomplished through such international collaboration as is taking place here.