• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.145-148
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• 2003

The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7； flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5； flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3； cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2； flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

• Journal of Conservation Science
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• v.29 no.2
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• pp.171-185
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• 2013

The purpose of this study were to interpret making characteristics and clay sources for Proto-Three Kingdoms period potteries which were excavated from Bakjimeure site in Tangjeong, Asan, Korea, on the basis of shape types. The pottery samples of the studied included deep bowl pottery, cylinder shaped pottery, duck shaped pottery and rounded based jar with short neck. And the last jar was dominant among them. This is supported in nearby Yongduri Jinter site, Galmaeri site and Baekseokdong site. They vary in terms of color of clay, absorption ratio and mineral classification. Based on the fact that their absorption ratio range was 4.50 to 25.19% and firing temperature range was 850 to $1,150^{\circ}C$, they were thought to be widely used. The equivalence of cylinder shaped pottery, duck shaped pottery and deep bowl pottery was high in terms of material characteristics and their firing temperature range was 850 to $950^{\circ}C$. However, the deep bowl pottery, compared to other pottery shapes, contained great amount of coarse grained quartz and feldspar, and was different from others in terms of function. For soil sample collected from relative plains (area 3) in the southernmost part of the site, their mineralogical and geochemical characteristics were the most similar to those of the potteries excavated from the Bakjimeure site and even most of the potteries collected from different sites.

• Journal of Conservation Science
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• v.33 no.3
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• pp.181-188
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• 2017

A total of 16 precious archaeomagnetic dating data were obtained from various historic sites including fired soils from eight archaeological sites on Jeju Island. We researched the measurement results of 12 pieces of data from before the Common Era (BCE), and four pieces of data from after the Common Era. First, the BCE data could be divided into three groups (A, B, and C) based on the difference in the archaeomagnetic data. By comparing the data accumulated in other parts of Korea and referring to the archaeological years, the order of the groups was as follows: A group (Bronze Age~Early Iron Age) ${\rightarrow}$ B group (Early Iron Age when the circular rim eomtodae pottery was excavated) ${\rightarrow}$ C group (Early Iron Age when triangulated rim jeomtodae pottery was excavated), with A group being the earliest data group and C group being the latest data group. In addition, the data after the Common Era could be used to determine the archaeomagnetic dating of the archaeological sites. Through the archaeomagnetic dating of Jeju's archaeological sites for the BCE period, the relative order of the relics was determined, and for the period after the Common Era, the absolute age of the historic sites was obtained. They are expected to be used diversely in the chronological study of Jeju.

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.77-88
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• 2007

Lateral earth pressure and horizontal displacement of the diaphragm walls constructed in multi-soil layers were analyzed by the field instrumentation from six building construction sites in urban area. The distribution of the developed earth pressure of the anchored diaphragm walls during excavation shows approximately a trapezoid diagram. The maximum earth pressure of anchored diaphragm walls corresponds to $0.45{\gamma}H$ and the earth pressure acts at the upper part of the walls. The maximum earth pressure is two times larger than the empirical earth pressure of flexible walls in sands suggested by Terzaghi and Peck(1967), Tschebotarioff(1973), and Hong and Yun(1995a). The horizontal displacement of diaphragm walls is closely related with supporting systems such as struts, anchors, and so on. The horizontal displacement of anchored walls shows less than 0.1 percent of the excavated depth, and the horizontal displacement of strutted walls shows less than 0.25 percent of the excavated depth. Therefore, the restraining effect of horizontal displacement to the anchored diaphragm walls is larger than the strutted diaphragm walls. In addition, since the horizontal displacement of the diaphragm walls is lower than the criterion, $\delta=0.25%H$, used for control the anchored retention wall using soilder piles, the safety of excavation sites applied with the diaphragm walls is pretty excellent.

• Journal of Conservation Science
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• v.25 no.3
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• pp.255-271
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• 2009

This study was examined interpretation of making techniques and provenance interpretation of raw materials for the potteries from the Nongseori site in Giheung based on archaeometric characteristics. The potteries are classified into three groups according to the archaeological age. The texture of Neolithic age potteries is sandy soil added a lot of temper such as talc and mica, and Bronze age potteries contain sandy materials which occur naturally include quartz, orthoclase, plagioclase and mica. On the other hand, Proto-three Kingdom Age potteries made of silty soil that sift out coarse minerals from the clay. But all pottery and soil samples in the study were very similar patterns with geochemical evolution trend. This result is sufficient evidence that all pottery samples were produced using the same raw materials from the host rocks around of the site area. The Neolithic age potteries had loose texture and fired probably about 700 to $760^{\circ}C$. The Bronze age potteries had experienced firing about 850 to $900^{\circ}C$. And Proto-three Kingdom Age potteries had compact textured and fired from 900 to $1,050^{\circ}C$. The making techniques of potteries are not represented discontinuation characteristics about the periodic time sequences, and are suggested that revealed a transitional change patterns for production techniques.

• Journal of Conservation Science
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• v.34 no.2
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• pp.97-106
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• 2018

The lime-soil mixture on barrier (LSMB) tomb is a representative type of tomb from the Joseon Dynasty. It is an important reference for understanding the society and funeral culture of that time. The LSMB excavated at the Gungri site were classified with manufacturing type. The ultrasonic velocity and rebound hardness method were used to estimate the physical properties of the LSMB. The strength values on the tomb of layered wall were different depend on measuring method. The compressive strengths of the tomb with layered wall, which is calculated by ultrasonic velocity and rebound hardness ranged from 4.0 to 355 (mean 43.6) $kgf/cm^2$ and 18.8 to 538 (mean 245.2) $kgf/cm^2$ ranges. The damage to the tomb with integrated wall during excavation and removal of the corpse could be a reason for the difference in results obtained using ultrasonic velocity method. Compressive strengths of tombs with integrated wall, which is calculated by ultrasonic velocity and rebound hardness ranged from 5.7 to 793 (mean 281.6) $kgf/cm^2$ and 4.5 to 550.5 (mean 172.4) $kgf/cm^2$ values. Physical properties on the tombs of integrated wall had different in compressive strength value but showed similar tendency. Thus, evaluation of the physical properties has shown that measuring ultrasonic velocity and rebound hardness methods are more effective in the LSMB with integrated walls. Further, the strength values obtained through the rebound hardness method are more constant than those obtained through the ultrasonic method due to the small detection area required by the former.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.4
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• pp.265-280
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• 2021

Population density due to urbanization is making people interested in underground space development and much interest in TBM construction with low vibration and noise. This led to a lot of research on TBM. However, research on the characteristics of the cutterhead opening of the TBM equipment being occluded under the ground conditions under which it is excavated is insufficient. Accordingly, a study was conducted to investigate clogging of the cutterhead opening during the shield TBM rolling. To identify the clogging of cutterhead openings in SHIELD TBM equipment, the reduced model experiment was divided into clay rate (10%, 30%, 50%, 60%), cutterhead opening rate (30%, 50%, 60%), and cutterhead rotation direction (one-way, two-way) and rotational speed (3 RPM) and conducted in 36 cases. Results of scale model test on shield TBM clogging, it was analyzed that the ground condition containing clay soil increased the clogging effect in both directions than the unidirectional rotation, and that the lower the rotational speed of the cutterhead, the less the clogging effect. Accordingly, the direction of cutterhead rotation, rotational speed and opening rate are calculated by taking into account ground conditions during ground excavation, the clogging effect can be reduced. It is believed to be effective in saving air as the clogging effect is reduced. Therefore, this study is expected to be an important material for domestic use of shield TBM.

• Journal of the Korean Geosynthetics Society
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• v.20 no.2
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• pp.45-56
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• 2021

As the utilization of the underground space is activated, deep excavation of ground has been conducted for the installation of underground structures, the earth retaining wall has widely used to minimize deformation of the excavated ground. In particular, as deep excavation is actively progressing in an urban area where structures are concentrated, methods to minimize the deformation of wall have been devised to prevent damage to the structure adjacent to the wall, and one of these methods is the pre-loading method. This method is a method of suppressing the deformation of wall by actively applying a load on the strut to be installed in wall, and research on this method has been conducted recently. However, although related studies have been actively conducted, the management standard for the pre-loading of bracing has not been clearly presented until now. In addition, since the working force in the strut may increase depending on the depth of excavation or the soil condition of the backfill, the magnitude of the pre-loading that can be applied to the brace may decrease. Nevertheless, the magnitude of the pre-loading (more than 50% of the working load) proposed by the previous research results has been uniformly applied to the strut. In this study, 3D finite element analysis was performed to evaluate the application range of the pre-loading of H-beam strut according to the soil conditions of backfill. As a result of the analysis, it was found that there is a very high possibility that a problem may occur in the stability of the structure of strut due to the earth pressure and the pre-loading when the soil condition is weak and deep excavation proceeds. And it was found that the application range of the pre-loading was 5%~70% of the working load in strut.

• Journal of Forest and Environmental Science
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• v.39 no.1
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• pp.20-26
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• 2023

Cow pea (Vigna unguiculata) was intercropped with Ziziphus spina-christi as summer forage in two consecutive seasons of 2017 and 2018. The aims to find out suitable agroforestry practice for saline soils of Khartoum State. And to investigate effect of tree spacing on forage biomass yield under semi -irrigated systems. Completely randomized block design with 3 replicates was conducted for this trial. Thus Z.spina-christi that fixed at 4×4 m was intercropped with cowpea at 1 m and 1.5 m spacing from trees trunk. Tree growth parameters were measured in terms of tree height, tree collar diameter, tree crown diameter and fruit yield per tree. While crop were parameters were determined in terms of plant height, number of plant, forage biomass yield per ha and land equivalent ratio. Soil profile of 1×1 m and 1.5 m depth was excavated and its features were described beside its chemical and physical properties were analyzed for 0-10 cm, 0-30 cm, and 30-60 cm and 60-100 cm layers. The results revealed that soil pH, CaCO₃, SAR, ESP, and EC ds/m were increased by increasing soil depths. Meanwhile tree growth in terms of tree height was significant in the first season 2017 when compared with tree collar diameter and tree crown diameter. Also significant differences were recorded for tree growth when compared with sole trees in the second season in 2018. Tree fruit showed marked variations between the two seasons, but it was higher under intercropping particularly at ZS2. Crop plant height was highly significant under sole cropping than intercropping in first season in 2017. In contrast forage biomass yield was significant under intercropping in ZS1 and ZS2 treatments. Land equivalent ratio was advantageous under this agroforestry system particularly under ZS2. Thus it recorded 5 and 9 for ZS2 in the two consecutive seasons respectively. Therefore, it is feasible to introduce this agroforestry system under such arid lands to provide summer forage yield of highly nutritive value and low cost for animals feed as well as to increase farmers' income and to halt desertification and to sequester carbon.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.44-63
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• 2000

Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.