• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.211-212
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• 2023

Building Information Modeling (BIM) design has been mandatory in Korea since 2016, and it has been gradually expanding in the industry, with a slow attempt to apply it in remodeling constructions. This is because Korea is facing a situation where many buildings are over 30 years old and require remodeling or reconstruction. The remodeling industry is also a growing market, as it saves construction time and cost compared to reconstruction. BIM is an ideal technology element for a competitive remodeling construction, as remodeling constructions face a complicated construction process from the start, including demolition, maintenance, and reinforcement to save the change process. However, there are still limitations in applying BIM to remodeling constructions, due to considerations of the existing building and the complicated requests of the inhabitants. BIM still has technical and environmental limitations for general use. In this study, I analyzed BIM application cases from existing studies and suggest what improvement points should be strengthened.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.311-318
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• 2018

When reinforced concrete structures are exposed to fire, their mechanical properties such as compressive strength, elasticity coefficient and rebar yield strength, are degraded. Therefore, the structure's damage assessment is essential in determining whether to dismantle or augment the structure after a fire. In this study, the confinement effect of lateral reinforcement of RC column according to the numbers of fire exposure face and stirrup was verified by fire resistant test with the heating temperatures of $400^{\circ}C$, $600^{\circ}C$ and $800^{\circ}C$. The test results showed that the peak stress decreases and peak strain increases as the temperature is getting higher, also transverse ties are helpful in improving the compressive resistance of concrete subjected to high temperature. Based on the results of this study, the residual stress of confined concrete under thermal damage is higher at the condition of more lateral reinforcement ratio and less fire exposure faces. The decreasing ratio of elastic modulus of more confined and less exposure faces from the relationship of load and displacement was also smaller than that of opposite conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.677-683
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• 2016

In urban areas, underground tunnel construction sites have spread widely to accommodate rapidly increasing traffic volume along with a high-degree economic growth. Earth tunneling might be adapted frequently for the underground space securing, and various tunneling methods have been developed to stabilize the tunnel face and crown. Among them, the DSM (divided shield method) is gaining popularity for its enhanced stability and construction efficiency. This method has its foundation from the Messer Shield method, which is one of the trenchless special tunneling methods. This study examined the effects of face reinforcement on construction the sequence through a large scale soil chamber test and numerical analyses. The chamber has a size of a 1/2 scale of the real tunnel. Surface settlements were measured according the tunneling process. Commercially available software, MIDAS GTS, was used for numerical analysis and its result was compared with the values obtained from the chamber test. The results of the study show that both settlements of the embanked soils and the stress of the tunnel girder are located within the safe criteria. Overall, this study provides basic data and the potential of using a reinforced tunnel face to enhance DSM applications.

• Tunnel and Underground Space
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• v.15 no.2 s.55
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• pp.111-118
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• 2005

The area of investigation belongs to Okchon metamorphic zone and the fault fractured zone runs parallel to the tunnel direction. It causes the independent decline of tunnel face and the slackness of the tunnel surrounding base so, after all, the severe displacement has occurred within the tunnel. Accordingly, the TSP(Tunnel Seismic Prediction) survey has been performed to investigate the extent of fault fractured zone and to analize its characteristics. Also, we have analized the behavior causes by performing the tunnel face mapping and drilling investigation, and confirmed the position and scale of geological anomaly area and front fractured zone which influences tunnel excavation and supporting. Collected data analyzed ground layer condition through 3 dimensional modeling. Several variables included in the modeling were analyzed by geostastistics. The analysis of the modeling data shows that the belt of weathering by fault fractured zone is developing on the basis of the right side of tunnel and that is decreasing to the left side. The fault fractured zone was confirmed that it has strike, $N0\~5^{\circ}E$ dip NW, and it is consisted of large-scale fractured zone including several anomalies. The severe displacement in tunnel is probably caused by asymmetrical load that n generated by the crossing of discontinuity and the rock strength imbalance of tunnel's both side by fault fractured zone, and judge that need tunnel reinforcement method of grouting etc.

• Journal of the Korean GEO-environmental Society
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• v.17 no.4
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• pp.39-46
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• 2016

The final stability analysis of the tunnel structure is generally evaluated by performing site monitoring to determine whether or not the measured value through the convergence after the completion of excavation in the face. When the ground conditions are so poor, the reinforcement around the tunnel was applied for enhancing the stability of tunnels. For the additional tunnel crown collapse or excessive displacement have occurred under construction, correlation analysis were performed for the comparison construction and numeric analyses. In this paper, we investigated the collapse types, tunnel collapse were mostly occurs at the crown and they were analyzed because of the geological conditions in the collapse zone. And also, it was analyzed as being correlated in the crown of tunnel exists a fault fracture zone which extends to the surface part. Thus, in case of ground conditions such as fault fracture zone with a tunnel extending from the crown to the surface, the behavior is larger than the behavior predicted by numerical method.

• Earthquakes and Structures
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• v.12 no.2
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• pp.237-250
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• 2017

There has been increasing attention in many countries on seismic retrofit of old fashioned RC structures in recent years. In such buildings, the joints lack transverse reinforcement and suffer inadequate seismic dimensional requirements and the reinforcement is plain bar. The behavior of the joints is governed by sliding of steel bars and diagonal shear failure is less influential. Different methods to retrofit beam-column joints have been proposed in the literature such as wrapping the joint by FRP sheets, enlargement of the beam-column joint, and strengthening the joint by steel sheets. In this study, an enlargement technique that uses external prestressed cross ties with steel angles is examined. The technique has already been used for substructures reinforced by deformed bars and has advantages such as efficient enhancement of seismic capacity and lack of damage to the joint. Three reference specimens and two retrofitted units are tested under increasing lateral cyclic load in combination with two levels of axial load. The reference specimens showed relatively low shear strength of 0.150${\surd}$($f_c$) and 0.30${\surd}$($f_c$) for the exterior and interior joints, respectively. In addition, relatively brittle behavior was observed and large deformations extended into the panel zone of the joints. The retrofit method has increased ductility ratio of the interior beam-column joints by 63%, and energy dissipation capacity by 77%, relative to the control specimen; For external joints, these values were 11%, and 94%. The retrofit method has successfully relocated the plastic joints far from the column face. The retrofit method has improved shear strength of the joints by less than 10%.

• Geotechnical Engineering
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• v.14 no.2
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• pp.31-40
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• 1998

To verify the reinforcing effect of the strips which are inserted in the backfill, but not connected to the face wall, model tests are executed. As the reinforcing effect is expected to reduce the active thrust acting on the retaining wall, test programmes included the measurements of the thrust. As a result. it is ascertained that the active thrusts are reduced by as much as 50%. Besides, efficient arrangement and the optimum length of the strips are verified. And the the number of reinforcing strips are increased, are close to the Rankine's hypothesis.

• Journal of Distribution Research
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• v.16 no.5
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• pp.85-101
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• 2011

Just as traditional markets nationwide, traditional markets in Jeju area also face a crisis due to expansion of new distribution channel and price competitiveness of large distribution companies. There are various support programs currently being carried out to prevent all risk factors of the traditional markets as government policies. But, these programs have failed to bring a positive change due to lack of specialized products of the traditional market, lack of systematic marketing and customer management, lack of market vendors' consciousness reformation. The purpose of this study is to prepare political measures to promote the revitalization of traditional markets in Jeju area and overcome these limits. To achieve this, this study analyzed the conditions of traditional markets in Jeju area and presented the specialization of items and service for each traditional market, establishment of growth strategies in connection with tourist industry and reinforcement of marketing competitiveness as measures to create a synergy effect.

• International Commerce and Information Review
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• v.10 no.3
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• pp.265-290
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• 2008

Domestic industries are facing the open era as a result of signing the Korea-U.S. FTA with no exception to the financial industry. The FFA between two countries is expected to produce pros and cons for domestic financial industry. Therefore, it is very important to minimize the shock caused by opening our financial market and to adopt the advanced financial tools actively. Signing the Korea-U.S. FTA and enforcing the Integration Law of Capital Market are leading a big crisis to the Savings Banks which have been shrinking under the dramatically changing domestic financial environment since the financial crisis. To cope with financial globalization, Korean Savings Banks are demanded to build up their concrete identity and reposition their status. This is related to shaping the long-term position of domestic financial industry. Therefore, the Savings Banks must take the growth strategy for their survival, and it is an inescapable choice. Several options are available: big scale operation and diversification of business functions, reinforcement of local-focused mediating function of funds, establishment of strategic alliance with other financial firms, reinforcement of risk management system and core competence, nourishment and employment of professional manpower, and active deregulation and policy support. When the Savings Banks are refurbished as an independent local bank performing the central role of local finance, the bright future can be their destiny under the enormously changing global financial environment. Also, two more conditions need to be satisfied: to establish horizontal networks among local banks directed by cooperative Korea Federation of Savings Banks to reverse the weak scale position, and to satisfy their own peculiar niche market with internal countermeasure to face global financial networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.400-413
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• 2016

The horizontal shear capacity when the flange of a steel girder is replaced with 80 MPa concrete is important for its structural safety. In this study, 6 specimens with different interface conditions were designed and fabricated based on the Limit State Design Code on Korean Highway Bridges and static tests were performed to measure the horizontal shear capacity. Not only the resistance factors of the stud shear connector, concrete and reinforcement, but also the surface conditions of the casing concrete and spacing of the horizontal shear reinforcements were used as the experimental variables. The experiments showed that the interfaces between the steel girder and the concrete flange have stronger joint performance than those between the concrete flange and deck slab. To ensure the composite action in the plastic zone, the conservative horizontal shear reinforcement is more important than the roughness in the concrete face.