• 보존과학회지
• /
• 제26권1호
• /
• pp.43-60
• /
• 2010

이 연구에서는 송광사 사천왕상 소조토의 정량적이고 객관적인 제작기법을 규명하고, 원료 산지를 추정하여 보존처리시 동일한 재료로 복원할 수 있는 기초 자료를 확보하였다. 이 결과, 사천왕상의 제작에 사용된 소조토는 층위와 대상에 관계없이 성인적으로 거의 동일한 흙으로 확인되었다. 그러나 소조토가 상대적으로 두터운 부위에서는 초벌층과 마감층에서 입도와 유기물의 함량을 달리하였고, 두께가 얇은 부위는 층위의 구분 없이 한 종류의 흙만을 사용하였다. 또한 복원토는 사천왕상의 소조토와 성인적으로 아주 유사한 흙이 사용되었으며, 층위에 따라 정선도의 차이를 보였다. 원산지 해석 결과, 추정산지 일대 흙은 소조토와 동일기원으로 판명되어 보존처리용 재료로 적합할 것으로 판단된다. 이 결과는 소조사천왕상의 무기재료학적 연구 및 보존처리에 크게 기여를 할 것으로 사료된다.

• 한국조경학회지
• /
• 제14권3호
• /
• pp.21-31
• /
• 1987

The overuse in the outdoor recreation lands has been deteriorating the natural resources and landscapes. So this study was executed to measure the users'impacts on vegetation and soil at Hwaum Temple District Campsite in the Mt. Jiri National Park, the southern part of Korea. Five sites were sampled in the study area according to the extent of impact observed. Then the users'densities and impacts on vegetation and soil were measured at each site. According to the result of this study, the numbers of species and individuals and the coverage of lower-layer vegetation showed outstanding changes by only light use. The numbers of species and individuals of middle-layer vegetation, species diversity indices, change rate in species composition of lower and middle-layer vegetation, damage rate of forces, contents of clay, soil moisture and organic matters, exchangeable base ions, soil hardness, organic matter depth and bare area of the campsite showed conspicuous changes from the site 4(19.6men / 1,000㎡). Especially, the self-repair of vegetation was impossible as the result of analysis of soil hardness and the formation of natural vegetation was expected to be difficult as the result of vegetation sturcture analysis over the users'average density of 19.6men /1,000㎡. The campsite management of this area shall be proposed as follows to prevent serious deterioration of natrual environment. A limitation of the present use and a conservation on soil and vegetation should be required at the site 4 and 5. Specially, prevention of camping recreation and artificial rehabilitation are necessary at the site 5(24. 3 men/1000㎡)

• 한국지진공학회논문집
• /
• 제5권3호
• /
• pp.19-27
• /
• 2001

구조물의 지진해석시 구조물-지반 상호작용의 영향을 무시할 수 없으며, 기초지반강성에 따른 구조물의 지진응답에 커다란 차이가 있다는 것은 이미 잘 알려져 있다. 이러한 인식에도 불구하고, 현재 벽식구조 아파트의 지진해석시 기조지반의 특성을 무시하고 기초가 매우 단단한 것으로 가정하여 지진해석을 수행하고 있다 본 연구에서는 구조형식이 독특한 의식구조 아파트 지진해석을 연약지반을 고려하여 수행하고, 지진응답을 암반과 UBC-97 지반조건의 연약지반을 고려한 지진응답과 비교분석하였다. 깊은 연약지반 위에 세워진 중, 저층 벽식구조 아파트의 내진거동은 기조의 절연효과로 지진응답이 크게 감소된 강체거동을 보여 UBC-97 설계응답스펙 트럼으로 내진설계를 하는 것은 보수적인 설계로 안전은 하지만 상당히 비경제적인 것으로 판단되었다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 춘계 학술발표회
• /
• pp.805-812
• /
• 2009

Permeation water resulting in the reclaimed land of waste can possibly cause the second pollution, such as the underground water and environmental pollution. Accordingly, Liner layer has been installed in the reclaimed land of waste to block and purify permeation water and prevent this second pollution. The material used as Liner layer is the one for water resistance and that of less than permeability coefficient $1{\times}10^{-7}cm/sec$ is widely used. As it is very difficult to secure in bulk this natural clay with low permeability around the field, the suitable way to secure low permeable material is that we use blend with good watertighness by mixing it with natural soil which is spread in the site. While this mixed soil which can resist water is commonly used in the site, bentonite mixed soil which is widely used as Liner layer in the reclaimed land of waste is recognized in Liner and durability. In this study, the engineering characteristics of soil-bentonite mixed liner are investigated using the laboratory hydraulic conductivity and uni-axial strength tests. The soil used for the liner is the clay soil located near the site. Mixing ratio of the bentonite which satisfies the requirement of hydraulic conductivity is determined and the optimum mixing ratio of bentonite is recommended for the landfill. After the mixed liner is constructed using the optimum mixing ratio of bentonite, the block samples of the constructed liner are obtained and the strength tests were performed. The hydraulic and strength properties of the liner for construction of the waste landfill were both satisfactory.

• Agricultural and Biosystems Engineering
• /
• 제1권1호
• /
• pp.30-37
• /
• 2000

Wet porous media representing agronomic soil that contains variable water content with variable electrolyte concentration was measured to study the shape of the curves of the electric double layer capacitance versus frequency (from 10 KHz to 10 MHz. This was done in an attempt to find the lowest practical operating frequency for developing low cost dielectric constant soil moisture probes. Cellulose sponge was used as the porous media. A high frequency electronic bridge circuit was developed for measuring the equivalent network parallel resistance and capacitance of porous media. It appears that the effects of the electric double layer component of the total parallel network capacitance essentially disappear at operating frequencies greater than approximately 25 MHz at low electrolyte concentrations but are still important at 50 MHz at higher concentrations. At these frequencies, the double layer capacitance masks the diffusion region capacitance where true water content capacitance values reside. The general shape of the curve of volumetric water content versus porous media dielectric constant is presented, with an empirical equation representing data for this type of curve. It was concluded that the lowest frequency where dielectric constant values which represent true water content information will most likely be found is between 30 and 50 MHz at low electrolyte concentrations but may be above 50 MHz when the total electrolyte concentration is near the upper level required for most mesophyte plant nutrition.

• Earthquakes and Structures
• /
• 제8권5호
• /
• pp.1241-1254
• /
• 2015

Spatially variable ground motions can be significant on the seismic response of a structure due to the incoherency of the incident wave. Incoherence of the incident wave is resulted from wave passage and wave scattering. In this study, wave passage effect on the response spectrum of a building structure built on a soft soil layer was investigated utilizing a finite element program of P3DASS (Pseudo 3-dimensional Dynamic Analysis of a Structure-soil System). P3DASS was developed for the axisymmetric problem in the cylindrical coordinate, but it is modified to apply anti-symmetric input earthquake motions. Study results were compared with the experimental results to verify the reliability of P3DASS program for the shear wave velocity of 250 m/s and the apparent shear wave velocities of 2000-3500 m/s. Studied transfer functions of input motions between surface mat foundation and free ground surface were well-agreed to the experimental ones with a small difference in all frequency ranges, showing some reductions of the transfer function in the high frequency range. Also wave passage effect on the elastic response spectrum reduced the elastic seismic response of a SDOF system somewhat in the short period range.

• 한국지반공학회논문집
• /
• 제18권2호
• /
• pp.5-12
• /
• 2002

본 연구에서는 연약지반 상에 축조되는 고속철도 노반을 보강하기 위해 사용된 지오셀의 효과를 평가하기 위해 다양한 현장 평판재하시험과 동적 모형토조시험을 수행하였다. 실험결과로부터 지오셀 사용에 의한 보강노반의 두께 감소효과와 노상 지지력 증가효과가 평가되었다. 지오셀 1층과 복토 loom를 사용하면 동일한 두에의 쇄석층을 사용할 경우와 비교하여 3~4배의 지지력 개선효과가 있으며, 노반두께를 약 35cm 정도 감소시킬 수 있는 것으로 평가되었다.

• 한국전산구조공학회논문집
• /
• 제15권1호
• /
• pp.9-20
• /
• 2002

본 연구의 목적은 비선형 흙-구조물 상호 작용문제를 연구하기 위한 계산 절차를 개발하는 것이다. 흙-구조물 상호 작용 거동을 연구하기 위하여 연직과 수평하중을 동시에 받은 대상기초와 강널말뚝으로 보강된 기초지반에 대한 유한 요소 수치해석을 하였으며 흙과 기초구조물 사이의 상호작용 거동을 모델하기 위하여 접합요소를 사용하였다 주 해석 결과는 다음과 같다. 1. 침하와 측방변위의 예측에 대해서는, 접합요소를 사용한 결과가 더 큰 값을 얻었다. 2. 극한지지력 결정에 대해서는 접합요소를 사용한 경우가 약 12%정도 더 작게 나타났다 3. 대상기초의 수평과 연직변위는 접합요소의 영향을 받았다.

• Architectural research
• /
• 제20권3호
• /
• pp.65-73
• /
• 2018

The restoration of foundations supporting the immense load of the stone pagoda at Mireuksa Temple Site prioritizes securing its structural stability. But so far, rammed earth construction is still not easy to determine the structural stability. This paper aims to emphasize that a scientific experimental study was conducted on a rammed earth construction, to identify its methodology and obtain objective data about structural stability of the foundation work. An experimental study fabricated specimens from the soil that had been removed during the excavation survey, determined the allowable bearing capacity through plate load tests, and compared the results with the predicted stress after reassembly of the stone pagoda to estimate the structural stability. Then, the repair method was selected based on the experimental study result. The evaluation method of the restoration of foundations consisted of an examination of the allowable bearing capacity and settlement. The allowable bearing of the reinforced foundation was more than twice the contact pressure under the stacked stones of the pagoda. The possibility of settlement of the rammed earth foundation soil layer during the pagoda assembly is expected to be very low because the settlement amount of the reformed soil layer is less than half of the settlement of the stabilized existing soil layer.

• 한국토양동물학회지
• /
• 제3권2호
• /
• pp.91-105
• /
• 1998

This study was conducted to analyze oribatid mites communities in deciduous forests in Namsan and Kwangreung on which different levels of environmental stresses might press, and to select potential condidate of biological indicator species. In overall, pH was lower in soil than in litter layer. Also soil pH, total nitrate content and soluble sulfate content were significantly higher in Namsan than in Kwangreung (p<0.05). The flora in Namsan and Kwangreung deciduous forests were dominated by Quercus mongolica, and Carpinus laxiflora respectively. It indicated that Namsan was in the lower stage of the floral succession. The number of species of oribatid mites was significantly higher in Kwangreung (39 families, 65 genera and 114 species) than in Namsan (32 families, 53 genera and 89 species) (p<0.05). Common species found in two regions were 77 species. Mean density of oribatid mites was 1.8 times higher in Kwangreung than in Namsan and this difference came mainly from litter layer. Among correlation analyses between environmental factors and oribatid mites density and species number, only density was negatively correlated with fresh litter depth in Namsan litter layer (r=-0.89, p<0.05). The pH which was considered to affect distribution of oribatid mites didn't show significant results.