• Journal of the Korean Geotechnical Society
• /
• v.15 no.4
• /
• pp.43-56
• /
• 1999

The use of berms can be an effective method to restrain excessive movements of wall and ground caused by deep excavations in urban area. But generally in construction sites, no berm remains for the sake of construction convenience or the geometry and magnitude of remaining berm is determined by individual experiences due to scarce research results. In this research, laboratory model tests and numerical analyses are used mainly for sandy soils. And efficient berms for restraining excessive movements by deep excavations are analyzed. Model tests were performed for the cases of cantilever and braced wall excavations, and the behaviors of retaining wall were analyzed according to the geometry and magnitude of berms. And also, numerical methods were used for analyzing efficient berms which are available in the soil and construction conditions in urban areas of Korea.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.10a
• /
• pp.556-563
• /
• 2005

Recently, it is used to join an building to an underground shopping-area in urban. When we construct Seo-Cho Complex building which is in Seoul, we also construct an underground passage to the Gangnam underground shopping-area. But it is difficult to excavate in the downtown area, because excavations induce traffic jam and public discontent. Considering safety, a confined area, settlements, we decided to use DSM(Divided Shield Method) which is based on messer shield. This paper will produce our experience and the results provide a useful guide in a connection tunnel

• Journal of the Korea Furniture Society
• /
• v.12 no.2
• /
• pp.39-47
• /
• 2001

This study was carried out to identify wood species excavated at the temple site of Backjae dynasty in Neungsanri, Buyeo. At the temple site, there were great excavations such as Backjae Incense Burner(National Treasure No.287) and Stone Reliquary(National Treasure No.288). The King Chang 13 Year carved on Stone Reliquary indicated that this temple was completed in A.D 567. Identification of wood species were as follows: The Temple building was constructed by Pinus densiflora Sieb. et Zucc. The species of the main pillar of Wooden Pagoda which preserved relics of the Buddha was Zelkova serrate Makino.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.10
• /
• pp.77-83
• /
• 2012

Recently, excavations using propped walls were popularized in downtown due to reduced settlement of nearby structures. These excavations is induced strain to propped walls or settlement in near ground. In this study, the ground reinforcing effect was proven using NDS, which is an inorganic injection material. Injection tests were performed to compute optimum injection pressure and volume. Next, calibration chamber tests were performed by using computed injection pressure and volume, and wall behaviour was examined for overburden pressures of 50kPa and 150kPa. Ground reinforcing effect was shown when the material behind the propped wall was grouted. From test results, optimum injection pressure was 350kPa and the optimum volume was 10L considering economics. Calibration chamber test results show that after the material was grouted, the maximum settlement was reduced to 19% of the non-grouted condition. For overburden pressures of 50kPa and 150kPa behind the wall, the settlement of the wall increased by 58% and 57% when compared to the case of no overburden pressure.

• Journal of Digital Convergence
• /
• v.13 no.5
• /
• pp.357-363
• /
• 2015

This study investigated the antioxidant and anti-inflammatory effects of Galla Rhois (Rhus verniciflua) on LPS (lipopolysaccharide)-stimulated human osteoblastic cells (MG-63). The aim of this study was to evaluate the LPS induced nitric oxide (NO) production and antioxidant radical in human osteoblast-like MG-63 cells. Therefore, the present work indicate that Galla Rhois extracts may be an ideal candidate for further research into their use for dental caries prevention component as well as, natural plant-based products. This suggested that 80% methanol and hexane extracts of Galla Rhois were inhibited NO generation and 1,1-diphenyl-2-pirylhydrazyl (DPPH) radical. Therefore, 80% methanol and hexane extracts of Galla Rhois may be utilized as a good source of protection against inflammation and oxidative stress. This study is intended to pursue wellness convergence in quality of life in the excavations in natural ingredients to create a variety of oral products with fewer side effects, cheap oral products for the dental treatment.

• Journal of architectural history
• /
• v.23 no.4
• /
• pp.91-100
• /
• 2014

There are lots of and kinds of stone pagoda and stone Buddhas at Unjusa Temple in Hwasun, Jeonnam, which is thus called as Cheontap(千塔) or Cheonbul.(千佛) Several archaeological excavations have been conducted in Unjusa though, the foundation purpose or background motivation is yet wrapped in mystery. Circular shape is representative pagoda of Unjusa made of round frame or spherical roof but circular stone pagoda is unusual that there is no similar example found in India or China as well as in Korea. Located in the symbolic center, Circular stone pagoda is a key to understand Unjusa. Yundeung(輪燈) is made of stone for circular stone pagoda and there are craft lamp and large lamp. The large lamp, for the palace courtyard on the occasion of Palgwanhoe,(八關會) consists of discs and light on each disc. Outdoor lamp of circular stone pagoda made of stone for permanent preservation purpose. Unjusa is a very special temple with stone-yundeung for circular stone pagoda. In this study, a circular stone pagoda that is the source of yundeung said. Unjusa circular stone pagoda next to the title of 'yundeung pagoda' and proposes to call.

• Geomechanics and Engineering
• /
• v.15 no.4
• /
• pp.965-972
• /
• 2018

In deep braced excavations, struts and walers play an essential role in the whole supporting system. For multi-level strut systems, accidental strut failure is possible. Once a single strut fails, it is possible for the loads carried from the previous failed strut to be transferred to the adjacent struts and therefore cause one or more struts to fail. Consequently, progressive collapse may occur and cause the whole excavation system to fail. One of the reasons for the Nicoll Highway Collapse was attributed to the failure of the struts and walers. Consequently, for the design of braced excavation systems in Singapore, one of the requirements by the building authorities is to perform one-strut failure analyses, in order to ensure that there is no progressive collapse when one strut was damaged due to a construction accident. Therefore, plane strain 2D and three-dimensional (3D) finite element analyses of one-strut failure of the braced excavation system were carried out in this study to investigate the effects of one-strut failure on the adjacent struts.

• Explosives and Blasting
• /
• v.29 no.1
• /
• pp.48-52
• /
• 2011

Non-electric detonator has been used in underground excavations because of its strong resistance against electric impacts. However, electric detonator is often used to initiate the non-electric detonator instead of using an exclusive non-electric blasting machine due to economical reason. Spark Trigger is introduced as a solution of unexpected explosive hazard from using an electric detonator as an initiator of non-electric system. Since Spark Trigger System does not need expensive tube and no plastic waste is left, this system is proved to be more economical and eco-friendly initiate system than the standard non-electric initiating system.

• 기술발표회
• /
• s.2006
• /
• pp.135-145
• /
• 2006

Soil nailing systems are generally many used in underground excavations and reinforcements of slopes since the first construction as a temporary retaining wall in 1993, Korea. In recently, they are many attempts to expand the permanent reinforcements of slopes However, experimental studies related to soil nailing systems are insufficient Specially, there are no researches related in the large scaled load tests of soil nailed walls in Korea In this study, a case study on the large scaled load tests of soil nailed walls is introduced and the behavior characteristic of them is investigated Also, they are proposed allowable deformation corresponding to the serviceability limit of soil nail walls and ultimate deformation corresponding to the collapse state of the walls. These results can be applied to the maintenance management of soil nailed walls And analysis on the required minimum factor of safety of soil nailed walls using the relation curve of load ratio and deformation ratio are carried out

• Korean Journal of Heritage: History & Science
• /
• v.33
• /
• pp.68-92
• /
• 2000

This paper reconsiders the users of iron arrowheads from Mongchon Earthen Wall(夢村土城). Because the Mongchon Earthen Wall has been seen as a major dwelling fort of the Hansong Period(漢城時代 : 18 B.C.~475), Paekche(百濟), these iron arrowheads have been considered as artifacts of the Hansong Paekche with no systematic analysis since they were found in 1985. However, uncovering numerous Koguryo artifacts, the excavations in 1988 and 1989 showed that Koguryo(高句麗) army had occupied the Mongchon Earthen Wall after they had conquered Hansong Paekche. In this paper, focusing on the formal similarity between these arrowheads and those from other Koguryo sites, I attempt to reconsider the nature of arrowheads from the Mongchon Earthen Wall. Found from a small pit, all of these arrowheads (88 in number) seem to have been contemporaneous. While all are stemmed, they can be divided into nine types on the basis of the shape of body and point. Most types are equal or similar to Koguryo arrowheads of other regions, and especially type F and G have not been found in southern Korean Peninsula. Accordingly, it is suggested that the existing models be reconsidered, and that Koguryo army who had conquered Hansong Paekche used these arrowheads around mid-5th century AD. Although at this point it is difficult to determine the users of these arrowheads only by analyzing several formal attributes due to Korean archaeology's little understanding of the arrowheads of the Three Kingdoms Period(三國時代), I expect that application of natural scientific methods will contribute to a better understanding.