• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.9-13
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with cement. And confirm the reinforcing effects with admixture such as cement. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and cement reinforced soil. In order to determine proper moisture content and mixing ratio, pilot test was carried out for soil and cement reinforced soil. And the mixing ratio of cement admixture was fixed 3%, 6%, 9% and 12% by the weight of dry soil. As the experimental results, the maximum dry unit weight(${\gamma}_{dmax}$) was increased with the mixing ratio and then shown the peak at 10% reinforced soil, but the optimum moisture content(OMC) and the volume change was decreased with the ratio increase. And the compressive strength volume change was decreased with mixing ratio increased.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.411-416
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• 1995

The single-pass perfusion experiments were performed in anesthetized rats to investigate the effects of perfusates and their osmolality on the water transport and to determine the correlation between the extent of water transport and the volume change of perfusate. Phenol red was used as a nonabsorbable marker. In normal rats, when perfused at a flow rate of 0.5 ml/min, 2-(N-rnorpholino) ethanesulfonic acid (MES) and S$\phi$rensen's phosphate buffers showed minimal net water transport as 0.125 and 0.173 %/cm of intestinal length, respectively. Hypotonic perfusate of 200 mOsm/kg of water and hypertonic perfusate of 400 mOsm/kg of water generated significant water transport compared with isotonic perfusate of 300 mOsm/kg of water. There was a linear correlation between the extent of water transport and the volume change of perfusate, suggesting that the volume change can be used as a measure of water transport.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.265-272
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• 2000

This study introduces the current theory of the SWCC and tries to verify the theory by performing laboratory tests for the local soils of Korea. First, the SWCCs of Poi-dong soil and Shinnae-dong soil, the most typical weathered residual soils in Korea, were experimentally obtained and the results were compared among others. Second, a SWCC model for deformable soils was proposed. For deformable soils, which show huge volume change during desaturation, the volume change behavior should be considered, and the SWCC should be expressed as a function of void ratio as well as suction.

• Geomechanics and Engineering
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• v.5 no.5
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• pp.401-417
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• 2013

The results of an experimental program regarding the effects of gradation on shear strength and volume change behavior of silty sands are presented. Consolidated drained direct shear tests were performed on two clean base sands and twelve silty sands obtained by mixing those base sands with two different non-plastic silts at various fines contents (${\leq}$ 25%). Drained shear strengths were observed to be not significantly influenced by either base sand gradation or silt gradation or fines content for the studied range. Increasing fines content has increased the volumetric contraction of specimens at similar void ratio. However, the amount of increase in volumetric contraction of silty sands were found to be affected by silt gradation when other influencing factors such as fines content, base sand gradation and mineralogy were kept the same. Moreover, the amount of increase in volumetric contraction of silty sands were also found to be affected by base sand gradation when other influencing factors such as fines content, silt gradation and mineralogy were kept the same.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1283-1287
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• 2009

The Korean government implemented 259 road projects from 2004 to 2007, valued at $18.4 billion. Change orders of these road projects occurred 8,973 times and, subsequently, caused significant increases in the cost of the projects, approximately up to $4.2 billion (22.8% of the initial budget). These significant problems of huge change orders require a more workable control system for budget management whereas the effectiveness of the government's control is still not satisfied. However, previous approaches and studies mostly limited their analyses to simply classifying the causes of the change orders. This paper investigates the real frequency and cost impacts incurred by each cause of a change order, primarily based on 218 road projects in Korea. The paper then identifies the attributes of change orders through a survey of 204 project participants in that those sources were inevitable or avoided if properly managed. The causes of the change orders are further analyzed with analysis of variance (ANOVA) in connection with contract volume, bid award rate, the contractor's capacity to perform, and the design company's capacity. This study found that if the contract volume is smaller, then the possibility of change orders is higher. Interestingly, if the bid award rate is less than 67.5%, it signifies the highest rate of change orders. In addition, the contractors whose construction ability is assessed as the top-ranked group showed the lowest change order rates. With these results, this paper provides the preventive guidelines for reducing the likelihood of change orders.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.155-165
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• 2003

A series of one-dimensional cylinder sedimentation test, seepage consolidation test and two-dimensional deposition model test were conducted to examine the characteristics of deposition and volume change of dredged soils containing the high water content, and these experimental results were compared with the sedimentary conditions of actual dredged-reclaimed fields to obtain the relations of a volume change by settling what is required for design. In addition, the change of water content and the distribution of fine grained soils after sedimentation were investigated. Thus, it was concluded that deposition height increased lineary as substantial soil volume increased, and also the elevation of interface increasea proportionately at both the starting time and the finishing time of virtual self-weight consolidation in one-dimensional sedimentation. Furthermore, the two-dimensional model test results were shown to describe the plain distribution of water content and fine grained silt where dredged soil was deposited by two dimensional flowing, and the water content was distributed to wide range from the minimum water content 30% to maximum 180% according to the passed amount of №200 sieve percentage.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1112-1120
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• 2017

Petroleum products are composed of various types of hydrocarbon compounds. Like other types of liquids, they presented the variation of density and volume according to temperature change. The method of measuring the density of petroleum products in a liquid phase is based on experimental data obtained mainly for each fractionally distilled petroleum product. In this study, the density and volume changes of kerosene and automotive diesel according to temperature change were measured and the property of change were analyzed. The conversion values were calculated using the density volume conversion table proposed by international standard ASTM. In addition, we analyzed the differences between the reference values and the measured values for the temperature changes specified in the domestic metering law.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.263-270
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• 2010

This research has reviewed the ways to improve the benefits of shortening of transit hours among the benefit items in analysis of economic efficiency. The existing way of calculating the benefits of shortening the transit hours in analysis of economic efficiency has been using O/D in peak to multiply by 365. This method has a problem of not considering the change of traffic according to the month and the day of the week. To improve such problem, the volume of traffics at 361 regular research branches of the chronological statistics of traffic volume was used to analyze the pattern change of traffic volume per day of the week and per month by t-test and cluster analysis. The results show a difference in traffic volume according to the day of the week and the month. In the research example, a supposed O/D and network were used to apply weight per day of the week and per month to see a slight difference with the existing method of calculating benefits of shortening the transit hours. This signifies the necessity to study about the weight to consider the change pattern of traffic volume.

• Geomechanics and Engineering
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• v.15 no.6
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• pp.1135-1141
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• 2018

Volume changes of soils induced by inorganic acids cause severe foundation and superstructure failures in industrial buildings. This study aimed to assess the potential of fly ash to control volume changes in soils under acidic environment. Two soils such as black cotton soil predominant with montmorillonite and kaolin clay predominant with kaolinite were used for the present investigation. Both soils exhibited an increase in swelling subjected to phosphoric acid contamination. Ion exchange reactions and mineralogical transformations lead to an increase in swelling and a decrease in compressibility in black cotton soil, whereas phosphate adsorption and mineral dissolution lead to an increase in swelling and compressibility in case of kaolin clay. Different percentages of Class F fly ash obtained from Ramagundam national thermal power station were used for soil treatment. Fly ash treatment leads to significant reduction in swelling and compressibility, which is attributed to the formation of aluminum phosphate cements in the presence of phosphoric acid.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1302-1311
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• 1993

In the 90 years or so since the beginning of the 20 th century , orchard growing and agricultural fields in Japan have undergone considerable change in terms of production volume, a seen in Fig. 1. as this change in volume progressed, sorting and packing machines have also grown from the first wooden tools, almost too simple to be called " machines" into sophisticated devices that bring together diverse technologies such as machinery , electronics, and optics. Nowadays, Japan/s agricultural industry is facing unprecedentedly serious labor shortage and the rapid aging of its experienced growers and producers, In additions, Japan has changed from a society oriented towards high-volume production and consumption to a more selective society which prefers smaller volume with the tastes of naturally ripended produce. With consumer trends changing there is a new demand on the part of growers for equipment that can not only measure the external quality of produce , but can measure inte nal quality as well.