• Journal of the Earthquake Engineering Society of Korea
• /
• v.8 no.4
• /
• pp.11-20
• /
• 2004

This paper suggests the site-dependent ductility factor which is a key component of response modification factor(R). To compute the ductility factor, a group of 1,860 ground motions recorded from 47 earthquake was considered. Based on the local site conditions at the recording station, ground motions were classified into four groups according to average shear wave velocity. This site classification was consistent with site categories of the UBC(1997), NEHRP(1997) and IBC 2000(1997). Based on the results of regression analysis, a simplified equations were proposed to compute site-dependent ductility factors. The proposed equations were relatively simple and provide a good estimation of mean ductility factors. Based on the proposed equation, ductility factors considering the site conditions can be evaluated in accordance with the present building codes.

• Journal of Korea Soil Environment Society
• /
• v.3 no.2
• /
• pp.127-145
• /
• 1998

Unlike water or air quality standards that have been established by legislation using potential human health impact as the primary criterion, soil quality depends on the soils primary function and its relevant environmental factors, which is much more site- and soil specific. A properly characterized soil quality assessment system should serve as an indicator of the soil capacity to produce safe and nutritious food, to enhance human and animal health, and to overcome degrative processes. For our proposed example, a high quality soil with regard to maintaining an adequate soil productivity as a food production resources must accommodate soil and water properties, food chain, sustainability and utilization, environment, and profitability, that (i) facilitate water transfer and absorption, (ii) sustain plant growth, (iii) resist physical degradation of soil, (iv) produce a safe food resources, (v) cost-effective agricultural management. Possible soil quality indicators are identified at several levels within the framework for each of these functions. Each indicator is assigned a priority or weight that reflects its relative importance using a multi-objective approach based on principles of systems to be considered. To do this, individual scoring system is differentiated by the several levels from low to very high category or point scoring ranging from 0 to 10, And then weights are multiplied and products are summed to provide an overall soil quality rating based on several physical and chemical indicators. Tlne framework and procedure in developing the soil quality assessment are determined by using information collected from an alternative and conventional farm practices in the regions. The use of an expanded framework for assessing effects of other processes, management practices, or policy issues on soil quality is also considered. To develop one possible form for a soil quality index, we should permit coupling the soil characteristics with assessment system based on soil properties and incoming and resident chemicals. The purpose of this paper is to discuss approaches to defining and assessing soil quality and to suggest the factors to be considered.

• Economic and Environmental Geology
• /
• v.48 no.2
• /
• pp.177-185
• /
• 2015

The objective of this study is to evaluate landslide hazard susceptibility and produce the landslide hazard maps for soil slope using checklists as a preliminary investigation method. Tables, proposed by NDMI (National Disaster Management Institute), are applied for slope stability assessment, and are comprised of checklists on soil slopes. Database including engineering properties of soil is constructed through the field survey and results from previous studies for The Mt. Hwangryoeng area at center of Busan. All data related to creating the thematic maps was carried out using ArcGIS 10.0. Results from using this method indicated that soil slope are evaluated from very stable to stable. Moderate stability has been partially presented along the edge of mountain. Results from landslide hazard maps can be used to prevent damage from landslides and facilitate appropriate land use planning.

• Korean Journal of Agricultural Science
• /
• v.32 no.2
• /
• pp.243-253
• /
• 2005

In agricultural ecosystem, soils which play important roles of storage and cycling of substances become a crtitical social problem due to rapid increase of contaminants with respect to our health. Soil as productivity should be interpreted as soil quality, that is important criteria in maintaining sustainable agriculture for production of safe food. Therefore, it needs to set the criteria of soil quality by considering environmental factors including relevant parameters which are involved in soil quality soil health because soils are widely distributed and have various characteristics such as physical, chemical, and biological propevties. Therefore, it requires intensive investigation of evaluation methods and development of related parameters for environmentally sound agriculture and safe soil management.

• Journal of the Korean Geosynthetics Society
• /
• v.12 no.3
• /
• pp.31-41
• /
• 2013

In this study, the properties of mudstone weathered soils related to landslides were analyzed at the area of landslide induced by heavy rainfall in Pohang. The soil tests were carried out to the soils obtained from landslide and non landslide sites, and the soil properties were investigated. The correlation between soil properties and landslides were analyzed using statistical technique, and then the soil factors were extracted from the correlation analysis. The correlation equation which can calculate the coefficient of permeability influenced on landslides was proposed using the soil factors. As the result of analysis, the porosity and unit weight of soils from the landslide area is smaller than those of soils from the non landslide area. The soils with poor grain size distribution and loose unit weight are prone to landslides because the soils have a large void ratio and a low unit weight. The permeability of soils from the landslide area is larger than that of soils from the non landslide area. According to the result of correlation analysis, the effective grain size, the saturated unit weight and silt and clay contents are evaluated as the influence factors. These factors were considered to estimate the coefficient of permeability of mudstone weathered soils.

• 어항어장
• /
• s.19
• /
• pp.41-49
• /
• 1992

• The Journal of Engineering Geology
• /
• v.17 no.3
• /
• pp.471-481
• /
• 2007

The Landslide in natural slope is occurred mostly by a heavy rain of the summer. This landslide is influenced in soil property of the surface than the rock mass. Soils in natural slope are created by weathering phenomena of the bedrock. These soils differed to the geological conditions such as sedimentary rock, metamorphic rock and volcanic rock. Therefore, estimation of landslide in natural slope is the most important analysis of the bedrock distributions and soil characteristics. This study analyzed the soil property to the natural slopes of Busan area where is distributed to volcanic rock, granite and sedimentary rock. Soil sample conducted various soil tests for estimate the soil physical property and soil engineering characteristics, and analysis of the correlation of geological conditions. In the experiment result, soils were mainly classified by a clayey sand. It is also established that $1.07{\sim}1.99kg/cm^3$ for wet density, $28.2{\sim}39.6^{\circ}$ for angle of shearing resistance, and $8.10{\times}10^{-5}{\sim}8.38{\times}10^{-2}cm/sec$ for coefficient of permeability. From the physical parameter, the soils are estimated to the permeable ground with good shear strength, and soil properties are showed a differential tendency for each geological condition.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.8
• /
• pp.67-75
• /
• 2004

The landslide is one of the most significant natural disasters, which cause a lot of loss of human lives and properties. The landslides in natural slopes generally occur by complicated problems such as soil properties, topography, and geology. Artificial Neural Network (ANN) model is efficient computing technique that is widely used to solve complicated problems in many research fields. In this paper, the ANN model with application of error back propagation method was proposed for estimation of landslide hazard in natural slope. This model can evaluate the possibility of landslide hazard with two different approaches: one considering only soil properties; the other considering soil properties, topography, and geology. In order to evaluate reasonably the landslide hazard, the SlideEval (Ver, 1.0) program was developed using the ANN model. The evaluation of slope stability using the ANN model shows a high accuracy. Especially, the prediction of landslides using the ANN model gives more stable and accurate results in the case of considering such factors as soil, topographic and geological properties together. As a result of comparison with the statistical analysis(Korea Institute of Geosciences and Mineral Resources, 2003), the analysis using the ANN model is approximately equal to the statistical analysis. Therefore, the SlideEval (Ver. 1.0) program using ANN model can predict landslides hazard and estimate the slope stability.

• 지반과기술
• /
• v.2 no.2
• /
• pp.36-44
• /
• 2005

• 지반과기술
• /
• v.9 no.1
• /
• pp.23-29
• /
• 2012