• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.3-14
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• 2005

Reliable predictions of the movement of earth retaining structures and the ground adjacent to braced walls in urban excavation are often difficult due to many variable factors. The ground settlement and the damage of adjacent structures in urban excavation has been an important issue. Therefore, the stability of the adjacent structures must be secured with the excavation support and research on the protection of adjacent structure is necessary. This study showed an urban excavation case and introduce observation method for case of damage behavior in urban excavation.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1130-1141
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• 2010

Even though a number of historic structures in Korea need to be repaired, an intensive research on their engineering performance has rarely been investigated. Herein, we attempted to provide a methodological approach via the explicit finite element analysis to investigate geotechnical aspect of the performance of the dry-stone wall structures. To do so, we summarized relevant literature on the world-wide historic stone structures as well as its analysis in terms of modern geotechnical engineering. The method of the explicit finite element analysis has been briefly summarized. The numerical results on an idealized block structure show that the displacement of blocks and the distribution of earth pressure is different from the conventional theory of the retaining wall because of the discrete nature of the dry-stone wall structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.49-52
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• 2011

This study concerned with the retention structures or inverted temporary building for displacement measurement in the underground soil after drilling a vertical tilt sensor attached to the vertical distance required to maintain a real-time measurement and management in order to install the wireless measuring devices installed in the field through remote control and management program for the safety of retaining structures temporary building be found on the internet in real time temporary building the retention is to develop a safety management system. And based on this technology to monitor the future status of the various structures possible to add a variety of sensors and Life Cycle Prediction of the structure and needs to evolve into intelligent systems and wireless networks using wireless communications infrastructure systems based on expanding domestic market penetration by developing instrumentation pioneer in overseas markets as well as the activation can also be judged.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.139-149
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• 2019

For retaining wall designs, horizontal earth pressure induced by traffic loads over the walls is calculated based on equivalent uniform pressure height. The AASHTO LRFD design standards propose equivalent uniform pressure height of traffic loads; however, the equivalent uniform pressure height is calibrated using the US standard trucks. As the domestic standard trucks are different from the US standard trucks, in this study, new domestic equivalent uniform pressure height is proposed using the Boussinesq theory varying vehicle directions, Poisson's ratios of pavement layers, and retaining wall height. The proposed equivalent uniform pressure heights are generally higher than those proposed by the AASHTO design standards because the axle loads and their densities of two domestic standard trucks are higher than those of the US standard trucks. The most highest equivalent uniform pressure height was found for traffic direction perpendicular to longitudinal direction of retaining wall.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.395-402
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• 2000

Recently, the deep excavations have been peformed to utilize the under ground space. As the ground excavation is deeper, the damage of the adjacent structure and the ground occurs frequently. The analysis of the retaining structures is necessary to the safety of the excavation works. There are many methods such as elasto-plastic, FEM, and FDM to analyze the displacement of the retaining structure. The elasto-plastic method is generally used in practice. In this thesis, GEBA-1 program by the Nakamura-Nakajawa elasto-plastic method was developed. The program for Windows was used the Visual Basic 6.0, and the Main of the program consists of three subroutines, SUB1, SUB2, and SUB3. The lateral displacement of the wall was analyzed by the developed program GEBA-1, SUNEX, and EXCAD, and compared with the measured displacement by the Inclinometer(at three excavation work sites). The excavation method of each site is braced retaining wall using H-pile. Each excavation depth is 14m, 14m, or 8.2m. The results of the analyses are the followings ① In the multi-layer soil, the lateral displacement by the GEBA-1 and EXCAD which is considering the distribution of the strut load is equal to the measured displacement. Elasto-plasto programs can't consider the change of the ground water in clay. Therefore, the analysis displacement was expected only 20% of the measured wall displacement. ③ At the final excavation step, the maximum lateral displacement of analysis and field occurred 7∼18m at the 85∼92% of the excavation depth. ④ The maximum lateral displacement in clay, as 50mm, occurred on the ground surface.

• Archives of Plastic Surgery
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• v.44 no.4
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• pp.266-275
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• 2017

Since the time of its inception within facial anatomy, wide variability in the terminology as well as the location and extent of retaining ligaments has resulted in confusion over nomenclature. Confusion over nomenclature also arises with regard to the subcutaneous ligamentous attachments, and in the anatomic location and extent described, particularly for zygomatic and masseteric ligaments. Certain historical terms-McGregor's patch, the platysma auricular ligament, parotid cutaneous ligament, platysma auricular fascia, temporoparotid fasica (Lore's fascia), anterior platysma-cutaneous ligament, and platysma cutaneous ligament-delineate retaining ligaments of related anatomic structures that have been conceptualized in various ways. Confusion around the masseteric cutaneous ligaments arises from inconsistencies in their reported locations in the literature because the size and location of the parotid gland varies so much, and this affects the relationship between the parotid gland and the fascia of the masseter muscle. For the zygomatic ligaments, there is disagreement over how far they extend, with descriptions varying over whether they extend medially beyond the zygomaticus minor muscle. Even the 'main' zygomatic ligament's denotation may vary depending on which subcutaneous plane is used as a reference for naming it. Recent popularity in procedures using threads or injectables has required not only an accurate understanding of the nomenclature of retaining ligaments, but also of their location and extent. The authors have here summarized each retaining ligament with a survey of the different nomenclature that has been introduced by different authors within the most commonly cited published papers.

• Journal of the Korean Geosynthetics Society
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• v.3 no.1
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• pp.3-15
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• 2004

Geogrid reinforced soil structures with segmental block facing have been increased since 1990's, because of the convenience of installation and the flexible appearance. In this paper, the behavior of the segmental reinforced retaining wall was analysed with the results of field monitoring. The height and length of reinforced wall are 12m and 25m, respectively. The field measurement equipments are horizontal and vertical earth pressure cells, settlement plate, strain gauge, inclinometer, and displacement pin. Based on the field monitoring, the horizontal earth pressure was approximately 0.3times higher than that of the theoretical method and the maximum tensile strength of reinforcement was 26.2kN/m. The displacement of facing wall was 23mm at the point of 7.1m height of the wall and toward the wall facing. The results of the study indicate that the segmental reinforced retaining wall is in a stable condition because of good compaction & reinforcement effects, and long period of construction time. Finally, the computer program of SRWall is very useful tool to design the segmental reinforced retaining wall.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.639-655
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• 2023

Recently, there has been a growing demand for underground space, leading to the utilization of earth retaining walls for deep excavations. Earth retaining walls are structures that are susceptible to displacement, and their measurement and management are carried out in accordance with the standards established by the Ministry of Land, Infrastructure, and Transport. However, managing displacement through measurement can be considered similar to post-processing. Therefore, in this study, we not only predicted the horizontal displacement of a retaining wall with ground anchors installed using machine learning, but also analyzed the impact of the prediction model based on data scaling and data splitting methods while learning measurement data using machine learning. Custom splitting was the most suitable method for learning and outputting measurement data. Data scaling demonstrated excellent performance, with an error within 1 and an R-squared value of 0.77 when the anchor tensile force and water pressure were standardized. Additionally, it predicted a negative displacement compared to a model that without scaling.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.323-328
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• 2001

In the ordinary reinforced earth wall, which was constructed by incremental construction method, the horizontal deformation of the facing due to the compaction induced horizontal earth pressure was unavoidable. Thus the KOESWall system which are adopted the isolated construction method was developed by I&S Eng. Co., Ltd. in 1999. Due to its systematical feature, KOESWall system is able to minimizes the horizontal deformation of reinforced wall effectively and it can be used as temporary structures more economically without the lacing block. In this report, it is shown that the concept and case histories of KOESWall system as a retaining structures.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.129-138
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• 2011

Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.