• International conference on construction engineering and project management
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• 2017.10a
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• pp.321-327
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• 2017

China is experiencing the urbanization at an unprecedented speed and scale in human history. The continuing growth of China's big cities, both in city land and population, has already led to great challenges in China's urban planning and construction activities, such as the continuous increase of construction and demolition (C&D) waste. Therefore, how to characterize cities' construction activities, particularly dynamically quantify the flows of building materials and construction debris, has become a pressing problem to alleviate the current shortage of resources and realize urban sustainable development. Accordingly, this study is designed to employ 4D-GIS (four dimensions-Geographic Information System) and Internet Plus to offer new approach for accurate but dynamic C&D waste management. The present study established a spatio-temporal pattern and material metabolism evolution model to characterize the geo-distribution of C&D waste by combing material flow analysis (MFA) and 4D-GIS. In addition, this study developed a mobile application (APP) for C&D waste trading and information management, which could be more effective for stakeholders to obtain useful information. Moreover, a cloud database was built in the APP to disclose the flows of C&D waste by the monitoring information from vehicles at regional level. To summarize, these findings could provide basic data and management methods for the supply and reverse supply of building materials. Meanwhile, the methodologies are practical to C&D waste management and beyond.

• Journal of the Korean GEO-environmental Society
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• v.15 no.4
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• pp.5-11
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• 2014

Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.

• Journal of Korean Library and Information Science Society
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• v.25
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• pp.405-439
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• 1996

During his reign, Kwang-Hae-Kun has done various works to promote literature and book acquisition. Among those works is the establishment of a special office called 'Tok Seo Dang' as he was enthroned in 1608, though it was demolished in 1622. And 'Seo Chuk Kyo In To Kam' was built to recover the scattered and lost books. He encouraged the people to collect and publish books by rewarding those who were engaged in a sort of library works. Their primary responsibility was to collect rare and essential resources, seek the material even in China and publish them using metal printing type. They even sought the diaries and newsletters which the individuals kept at their house. The collected materials were first copied and then kept in 'Shilok' shrine. Among the imported books are Dae Myung Hoi Chon, Chon Choo Sa Chon, Tong Kam Chan Yo, Du Si Tong Chon, Ok Hae, Mun Seon, Hak Hae, Lim Geo Man Rok and some were without titles. Majority of the compiled materials were medical books and geographies like Shin Cheung Tong Kak Yeu Chi Seung Ram, Tong Eui Po Kam, etc. Because of this strenuous effort, they were able to collect and retrieve lots of books and materials between 1608 and 1623. Majority of the published books were of Confucianism(13) which were followed by Political and Legal items(5), Historical documents(3), literature (3), etc. Regarding our library history, one should never forget Kwang-Hae-Kun's significant and remarkable contribution to it.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1046-1050
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• 2010

During construction of a sea-crossing bridge grouting was used to fill densely the space between the bottom of caisson and the ground. This grout mixture was mixed with an anti-washout admixture after locating accurately the pre-cast caisson on three concrete landing pads. This method differs significantly from the costly conventional method, for bridge foundations offshore, where concrete is placed in situ after excavating inside of a temporary concrete coffering wall. To verify the grouting method in advance, the full-scale field tests were performed twice on land. After identifying the fluidity of the grout material to be filled, finding some possible problems with the main construction and revising the original design, the main construction has been continuing successfully with 20 caissons completed to date. The purpose of this paper is to introduce for the first time in Korea the grouting method including the automatic and the manual monitoring system based on the main construction of the caisson foundation.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.207-215
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• 2004

In this study, the upper bound theory is applied to a reinforced slope to develop an limit state analysis method. As processing of this upper bound theory in formulating finite element, the basic idea of numerical method can be obtained from a macroscopic point of view with an anisotropic homogeneous material. The reinforced soil strength reliability depends on properties of reinforcements which consist of the interaction of interfaces between back fill and reinforcements. Both soil's mechanical property and overall behaviour of reinforced soil can be controlled via arranging geometry and relative proportions of reinforced soil. Therefore, the upper bound theory can not only predict the particular limit state action of reinforced soil slope but also is efficiently able to estimate the local plastic failure.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.745-751
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• 2009

The anchor is used extensively for a cutting slope, an earth retaining wall, an uplift resistance of sub-structures and so on at civil engineering projects and is classified by aim in use, tendon material, and ground/tension fixing type. It can be distinguished extensively into friction type, bearing type, and complex type by ground fixing type. Generally, bond length of friction type anchor has application to 3~10m depending on the friction-resistance characteristics. In this study, 'DEW(double enlargement wedge) bearing type anchor' of new concept is devised. The bond length is about 0.6~0.8m. It can be used on the ground to have the strength characteristics above it of weathered rock. There are merits which are 'period reduction' and 'cost saving' through the minimum of the boring length. In addition, it is so called environmentally friendly Methods because it can reduce the quantity of carbon dioxide through the reducing drilling machine operation time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.194-195
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• 2013

Recently, it is the tendency that the CO₂ gas generated in the manufacturing process is increased every year in case of the portland cement used in the most of constructions and civil engineering field. The method that uses the mineral admixtures as the cement substitute material in order to be more serious and as much as it occupies 7% of the global CO₂ gas outlet amount such as 1 ton produces the cement and it ejects the CO₂ gas of 0.4~1.0 ton, etc conclude this problem is examined. Therefore, PVA fiber was mixed into the inorganic binder recycling the blast furnace slag, which is the industrial byproduct with the purpose studying the Geo polymer which doesn't use the cement at all silica fume, red mud, and etc. In addition, the water curing temperature was differentiated and the strength characteristic of the curing body tried to be examined.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.86-94
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• 2015

A series of injection and drainage test were conducted on an circular acrylic tube to investigate the pressure generated by the accumulated fill materials inside a circular acrylic tube structure. The acrylic tube was filled by means of gravity filling with a slurry material having an average water content of 700%. The water head during the filling process was 1.8m and the bottom pressure during initial filling was 20.18kPa. The recorded stress at the sides of the acrylic tube was 17.89kPa during the filling process and was reduced to 13.58kPa during the leaving process. Continuous drainage of the acrylic tube has greatly influenced the stresses around the tube structure. As the water is gradually allowed to overflow, the generated pressure at the topmost pressure sensor of the tube was reduced further to 2.17kPa. Eventually, the initially liquid state slurry material transforms into plastic state after water has dissipated and substantial soil particles are deposited in the acrylic tube. The final water content of the deposited silt inside the acrylic tube after the test was 42%. It was found that the state of stresses(geo-static earth pressures) in the acrylic tube was anisotropic rather than isotropic.

• Geomechanics and Engineering
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• v.3 no.4
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• pp.291-321
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• 2011

The paper describes a simple numerical FLAC model that was developed to simulate the dynamic response of two instrumented reduced-scale model reinforced soil walls constructed on a 1-g shaking table. The models were 1 m high by 1.4 m wide by 2.4 m long and were constructed with a uniform size sand backfill, a polymeric geogrid reinforcement material with appropriately scaled stiffness, and a structural full-height rigid panel facing. The wall toe was constructed to simulate a perfectly hinged toe (i.e. toe allowed to rotate only) in one model and an idealized sliding toe (i.e. toe allowed to rotate and slide horizontally) in the other. Physical and numerical models were subjected to the same stepped amplitude sinusoidal base acceleration record. The material properties of the component materials (e.g. backfill and reinforcement) were determined from independent laboratory testing (reinforcement) and by back-fitting results of a numerical FLAC model for direct shear box testing to the corresponding physical test results. A simple elastic-plastic model with Mohr-Coulomb failure criterion for the sand was judged to give satisfactory agreement with measured wall results. The numerical results are also compared to closed-form solutions for reinforcement loads. In most cases predicted and closed-form solutions fall within the accuracy of measured loads based on ${\pm}1$ standard deviation applied to physical measurements. The paper summarizes important lessons learned and implications to the seismic design and performance of geosynthetic reinforced soil walls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5176-5183
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• 2013

In general, Korean Lightweight Concrete used Heat insulating material for building and filler for civil construction, backfill material for tunnel, office floor fillers, lightweight blocks and so on. These expand the range of use ALC(autoclaved lightweight concrete) on the soft-ground at regular intervals during road construction by installing piles used as substrates for the process is under study. In this study, behavior characteristics on the soft-ground of pavement analysis was used to test the geo-Centrifuge. Prototype pavement reduced to 1/30 slab form of the composition as kaolinite model tests were conducted in the soft ground. Pile Arrangement (having 36 component pile with an array of $3{\times}12$) was used to group of piles. Tests of gravity 30 level the centrifugal force acting Light-weight pavement models. Based on the Prototype pavement of the behavior characteristics of pavement behavior characteristics were estimated. FMA analysis of the 10 times as big 39.4kg (actual load 35 ton) of the lateral load is applied to the case 7.8mm (actual behavior 23.4mm) behavior was fine.