• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.191-201
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• 2000

In this study, the earth retaining structure using a row of piles considering plastic flow of the ground is suggested for shallow excavation works instead of conventional anchored sheet-pile wall method in the marine clays with high groundwater level. The behavior of the earth retaining structure using a row of piles is precisely observed during excavation by inclinometer and piezometer installed in opposite to the excavation side. As a result of field measurement, it was found that the behaviors of the piles and the soil were influenced mainly by slope of excavation face, interval ratio of piles, fixity condition of pile head, and stability number, etc. The earth retaining structure using a row of piles is ascertained for workability, stability, and economical construction on the soft ground having no adjacent structures.

• Geotechnical Engineering
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• v.35 no.6
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• pp.21-27
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• 2019

• Journal of the Korean Geotechnical Society
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• v.25 no.1
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• pp.41-54
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• 2009

The purpose of this research is to introduce the new temporary earth retaining wall system using landslide stabilizing piles. This system is a self-supported retaining wall (SSR) without installing supports such as tiebacks, struts and rakers. The SSR is a kind of gravity structures consisting of twin parallel lines of piles driven below excavation level, tied together at head of soldier piles and landslide stabilizing piles by beams. In order to investigate applicability and safety of this system, a series of experimental model tests were carried out and the obtained results are presented and discussed. Furthermore, the measured data from seven different sites on which the SSR was used for excavation were collected and analyzed to investigate the characteristic behavior lateral wall movements associated with urban excavations in Korea. It is observed that lateral wall movements obtained from the experimental model is in good agreement with the general trend observed by in site measurements.

• Journal of the Korean GEO-environmental Society
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• v.13 no.5
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• pp.25-33
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• 2012

In this study, gathered measuring data at fields constructed by IPS(Innovative Prestressed Support) system controls the ground displacement and improves the constructability of earth work and structure work greatly, and compared with horizontal displacement calculated by Elasto-plastic analysis program(EXCAV/W). As the result, displacement of calculated by pre-loading data is reduced 13.2% average of general method, and measuring displacement is also reduced 26.7% average of general method. Therefore that IPS system is more safe than conventional strut method in contrast to displacement of underground wall. In addition, horizontal displacement is reduced through the pre-loading effect used by IPS system.

• Tunnel and Underground Space
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• v.18 no.2
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• pp.118-124
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• 2008

Allowable level of blasting vibration for earth retaining wall was examined in this study. Blasting vibration was measured at near field blasting to evaluate the influence of the blasting work to earth retaining wall and rear ground. Although small scale blasting with $0.5{\sim}2.0kg$ explosives per round merely influenced to the structure and ground, but it was suggested to blast at the distance of twice the least burden considering the block movement.

• Journal of the Korean GEO-environmental Society
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• v.23 no.11
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• pp.5-11
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• 2022

The objective of this study is to evaluate the mechanical properties of high-flowable retaining wall material (RWM) incorporated with ground granulated blast-furnace slag (SG) and steel fiber (SF) based on a comparison with those of ordinary portland cement (OPC). To produce the specimens of RWM, some chemical agents such as superplasticizer (SP), air-entrained agent (AEA) and viscosity modifying agent (VMA) are added in the fresh RWM. The compressive, split tensile and flexural strength measurements were performed on the hardened RWM specimens. Additionally, surface electric resistivity and absorption tests according to ASTM standards were carried out at predetermined periods after water curing. It was found that the mechanical properties of slag cement concrete (SGC) RWM mix are better than those ordinary portland cement concrete (OPC) RWM mix. The effect of SF is remarkable to improve the mechanical properties of RWM mixes. It is noted that the usage of SG shows a beneficial effect to resist water penetration as well as long-term strength development of RWM mixes.

• Journal of the Korean GEO-environmental Society
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• v.24 no.6
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• pp.13-20
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• 2023

This paper is aimed to evaluate the mechanical properties and durability of high-flowable retaining wall material (RWM) with different levels of steel fiber (SF) content. To produce the specimens of RWM, some chemical agents such as superplasticizer (SP), air-entrained agent (AEA) and viscosity modifying agent (VMA) were added in the fresh RWM. The compressive and split tensile strength measurements were performed on the hardened RWM specimens at the predetermined periods. Additionally, surface electric resistivity and absorption tests according to ASTM standards were carried out to examine mechanical properties of RWM mixes. The durable performances such as chloride ions penetrability and freezing-thawing resistance of RWM mixes were experimentally investigated. As resutls, it was found that the performance of RWM mix with SF were much better than that without SF, especially at the 2% addition of SF. Thus, it is noted that the proper addition of SF in the RWM mix may have a beneficial effect to improve mechanical properties and durability of RWM mixes.

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.65-74
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• 2004

Based on the field measuring data obtained from seven excavation sections in Inchon International Airport Project, the horizontal displacement of sheet piling walls supported by anchors and the lateral earth pressure acting on sheet piling walls was investigated in soft ground. The proposed diagram of lateral earth pressure is a rectangular form, and the maximum earth pressure corresponds to $0.6\gamma H$. The maximum earth pressure is similar to the empirical earth pressure proposed by NAVFAC(1982). The quantitative safe criterion of sheet piling walls with struts is established from the relationships between increasing velocity of maximum horizontal displacement and stability number in excavated ground. If the velocity of maximum horizontal displacement shows lower than 1mm per day, the sheet piling walls exist under stable state. When the velocity of maximum horizontal displacement becomes more than 1mm and less than 2mm per day, excavation works should be observed with caution. Also, when the velocity of maximum horizontal displacement becomes more than 2mm per day, appropriate remediations and reinforcements are applied to sheet piling walls.

• Journal of the Korean GEO-environmental Society
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• v.23 no.1
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• pp.25-30
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• 2022

It is very important to investigate the ground properties of a construction site for the stability during the construction of the retaining wall. In the retaining wall construction stage, ground properties are checked through ground investigation, but the actual ground properties may be different from the ground investigation result. In order to analyze the stability of the retaining wall in real time, it is important to reflect the properties of the actual ground. Also, when it is judged that the wall is unstable, an appropriate solution must be provided for the stability of the wall. This study aims to present a technique for predicting the actual ground properties through a differential evolution algorithm and judging the stability of the earth wall in real time through the digital twin of the retaining wall.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.681-688
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• 2022

According to a recent study, most construction companies in Korea do not manage risk effectively, and it is judged that the risk management system needs to be improved. In addition, most risk-related studies deal with risks from a macroscopic perspective, and there are few studies dealing with process risks at the project construction stage. Therefore, this study tried to suggest a risk response plan through analysis and classification of risk factors that may occur in retaining work among process risks. To this end, a workshop was held for risk experts to identify and analyze risks that may occur during the construction of retaining work for apartments. As a result of the study, it was expected that savings of KRW 4.97 billion would be possible in the 95 % confidence interval, and the maximum possible cost was reduced from KRW 15 billion to about KRW 10 billion. Based on the risk reduction ratio, it was found that risks that can be reduced without any special input cost, risks with large effects in response to risks, and risks with insignificant effects were found. Therefore, using the types and risk factors presented in this study as guides, it is expected that it will be helpful in successfully operating the project if an appropriate response strategy is prepared and systematically responded to the site conditions.