• Magazine of korean Tunnelling and Underground Space Association
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• v.12 no.3
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• pp.57-64
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• 2010

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3729-3744
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• 2011

As the size of structures become larger by civil and architectural structures becoming large, deeply underground, and high-rise, the conditions of underground foundation vary according to the location that the lack of bearing capacity locally because of ununiform of foundation in some parts is frequent. Generally, when the foundation is not homogeneous, the acquisition of safety through applying the most conservative foundation method possible becomes the focus to secure the stability of the superstructures. It is considered as because of inability to verify the application and stability and application of construction of different foundations through an outlined review because of lack of study in case of different foundation of mixed use of direct foundation and pile foundation. Therefore, through measurement interpretation of the different foundation in which the direct foundation and pile foundation are mixed in use, the grounds in which the hypothetical bearing capacity changes dramatically was modeled to evaluate the applicability of different foundations. Also, based on the results of measurement interpretation, various foundations are created by using plaster, Joomunjin standard soil, and rubble to conduct an indoor model test to compare and analyze the movement of pile foundation and different foundations. Based on such research results, the stability and applicability of the different foundations which is more efficient and economical than the existing foundations in case of grounds in which the bearing capacity changes dramatically by comparing and analyzing the different foundations (direct foundation + pile foundation) with the conservative pile foundation and mat foundation. As a result, when the different foundation is applied, the overall settlement amount increased than the conservative pile foundation. However, the difference was very minute and it has been confirmed to be no issue as a result of assessment of stability of the differential settlement of structures through critical angle displacement.

• Journal of the Korean GEO-environmental Society
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• v.24 no.5
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• pp.5-12
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• 2023

Recently, due to urban development and expansion, construction plans have been increasing adjacent to existing tunnel structures such as subways, roads, and large pipelines. Structural plans adjacent to existing tunnels have different effects on tunnel stability depending on the construction method, degree of proximity, and location of new structures. In particular, the pressure water tunnel shows a very large difference from other road tunnels and railway tunnels in geotechnical characteristics and operation characteristics. Therefore, it is necessary to review the safety zone due to adjacent construction in consideration of the geotechnical characteristics of the water tunnel and the new sturure construction method. In this study, the existing tunnel safety zone standards were investigated. A stability evaluation performed numerical analysis considering the deterioration of concrete lining in operation and the characteristics of water tunnel. In addition, the impact of vibration caused by pile construction and blasting excavation of new structures was reviewed. Based on this, a pressure water tunnel safety zone was proposed in consideration of adjacent construction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.485-502
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• 2021

In order to evaluate the impact of ground subsidence and superstructures that are inevitably caused by tunnel excavation, a total of seven major influencing factors of surface subsidence and structural soundness reduction were set, and a Parameter Study using numerical analysis was conducted. Stability analysis was performed using scheme of Boscardin and Cording method and the maximum subsidence amount and the angular displacement, and correlation analysis was performed for each major influencing factor. In addition, it was applied that used the mutual behavior of the ground and the structure by parameter analysis in the site of the 𐩒𐩒𐩒 tunnel located in Hwaseong-si, Gyeonggi-do, and the applicability of the site was analyzed. As a result, the error was found to be 1.0%, and it could be used as a basic material for determining the appropriate tunnel route under various conditions when evaluating the stability of the structure according to tunnel excavating at the design stage.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.295-306
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• 2021

This study used numerical modeling to investigate the stability of railway roadbed in areas with various underground cavities and rock conditions associated with mining activities. It compared combined loads from both passenger and freight trains with loads from only passenger trains. Stability was assessed with reference to the Korean government standards for railway subsidence allowance and railway warping repair. Sufficient stability regarding the railway subsidence allowance standard was not achieved when cavities were at depths of <5 m. The criteria for requiring railway warping repair were met when cavities were at depths of <15 m, depending on the rock fracture condition. This study provides the first report on systematic analysis land subsidence related to cavity size and rock fracture conditions associated with mining activities. We expect that this study could serve as an important reference for railway construction in mining areas.

• Geotechnical Engineering
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• v.11 no.2
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• pp.79-98
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• 1995

In the present study an analytical modeling was carried out to predict mobilized shear strength at the interface between the nail and surrounding soils by carefully examining the behavior characteristics of nailed boil excavated walls. Based on the developed model of mobilized shear strength, the method of overall stability analysis of nailed -soil walls was also developed using the Morgentern -Price limit -equilibrium slice method. The developed analytical procedure could predict the behaviors of nailed -soil excavated walls during the successive excavation stages, at the final stage of construction and post -construction stages. To verify the validity of the developed model and method of stability analysis, mobilized tensile forces of nails and overal stability estimated by the developed procedure were compared with test measurements from three nailed -soil experimental walls having different soil conditions. The effect of seepage pressures inside the soil mass was considered in the developed procedure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.116-117
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• 2014

This study is to environmental safety assessment of ground solidification materials using industrial by-products. also, physical and chemical properties were investigated. as a result, compared to conventional cement the survival rates are capable, was judged to be possible utilizing of ECO-friendly ground solidification materials.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.21-38
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• 2006

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.103-112
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• 1990

This study examines the characteristics of soil behavior which includes many uncertainties in seismic design, evaluates the dynamic soil properties and studies the soil-structure interaction to generalize the applicability and economy of the available sites. An example analysis is performed for soil-structure system response assuming a containment structure built on site which includes soil layers using both elastic halfspace analysis and FEM analysis against the seismic loads from the actual design. This exercise is performed as a part of the safety analysis and economic assessment of the nuclear power plant built on soils. It includes the preparation of computer program capable of incorporating large nonlinearity in the analysis, resonable evaluation procedures to determine input soil data. Nonlinear FEM analysis of Seed and Idriss model is found suitable for the accurate analysis of dynamic response of soils. Linear FEM analysis using dynamic soil properties at strain level obtained by one-dimensional seismic response, and elastic half-space analysis using dynamic soil properties at strain level under static loads are recommended to evaluate the dynamic soil properties.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.174-181
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• 2001

The cavities created by underground mining, if remained unfilled, can cause ground settlement and surface subsidence as a result of relaxation and breakdown of the carven roof. Construction of structures above the underground mine cavity will have serious problems concerning both structural stability and safely even if the cavity is back-filled. This study was conducted to confirm the location and condition of the cavern as well as the state of the back-fill in A mine area using core logging and borehole camera. The bearing capacity and other mechanical properties of the ground were also measured by the standard penetration test(SPT). Obtained data were used to assess the stability of the ground and the structures to be built by numerical analysis using FLAC. The site investigation results showed that the mine cavities were filled with materials such as boulder and silty sand(SM by unified classification). Result of the numerical analyses indicated that constructing building structures on the over-lying ground above the filled cavities is secure against the potential problems such as surface subsidence and ground settlement.