• Geomechanics and Engineering
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• v.1 no.3
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• pp.179-191
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• 2009

For a two-way drainage deposit under a surcharge load, it is possible to leave a layer adjacent to the bottom drainage boundary without prefabricated vertical drain (PVD) improvement and achieve approximately the same degree of consolidation as a fully penetrated case. This depth is designated as an optimum PVD installation depth. Further, for a two-way drainage deposit under vacuum pressure, if the PVDs are fully penetrated through the deposit, the vacuum pressure will leak through the bottom drainage boundary. In this case, the PVDs have to be partially penetrated, and there is an optimum installation depth. The equations for calculating these optimum installation depths are presented, and the usefulness of the equations is studied by using finite element analysis as well as laboratory model test results.

• Journal of Welding and Joining
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• v.28 no.6
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• pp.45-50
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• 2010

Most of joining processes for machine and steel structure are performed by butt and fillet welding. The mechanical properties and fatigue strength of their welding zone can be effected largely by the differential of generated heat and changes of grain size according to thickness of material and number of passes in welding process. In this study, it was investigated about characteristics of fatigue failure according to thickness of material and number of passes in cruciform fillet weld zone as the basic study for safe and economic design of welding structures. Fracture modes in cruciform fillet weld zone are classified into toe failure and root failure according to non-penetrated depth. It can be accomplished economic design of welding structures considering fatigue strength when the penetrated depth in fillet weld zone is controled properly.

• Journal of the Korean GEO-environmental Society
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• v.18 no.5
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• pp.45-53
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• 2017

IPM bridge was developed to revise the problems of IAB bridge by Nam et al, (2016). This research conducted the p-y analysis to examine the parameter traits among the protruded length (H), penetrated length (L) of pile bent and soil conditions. From the results, the maximum bending moment happened in the top segment of pile bent, because it is integrated to the upper structure. Also, the maximum shear force was shown in the boundary of the sand and weathered soil zones according to the analysis soil conditions. The maximum member force and unbraced length is converged when the ratio (L/H) of protruded length (H) and penetrated length (L) is 1.0. The larger material force is happened, if the pile bent is penetrated shallowly compared to the protruded length. The definite inflection points were shown in the horizontal displacement curve from the p-y analysis, also the smaller penetrated length made the curve grade slower.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.3-16
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• 1999

A series of model tests was conducted to investigate the one-dimensional consolidation behavior of an improved ground where sand compaction piles(SCP) were either fully or partly installed in the model clay ground. In order to check the one-dimensional consolidation settlement and stress concentration ratios, earth pressure, pore pressure transducers and dial gauges were installed in the model clay ground. The test results revealed that the consolidation settlement of the partly penetrated SCP ground was larger than that of the fully penetrated SCP ground, and the stress concentration ratios (m) of the fully penetrated SCP ground were higher than these of the partly penetrated SCP ground. The stress concentration ratio was decreasing with the increase in the penetration depth of SCP.

• Journal of Welding and Joining
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• v.29 no.4
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• pp.67-72
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• 2011

The proportion of the welding in the production process of machinery, buildings and marine structures is increasing and the joining are mainly conducted by butt and fillet weld. In the case of fillet weld, the shape of structures is complicated depending on the constraint on the geometry of the structures, therefore, the full penetration is mostly difficult. Accordingly, it is necessary to establish safe and economical criteria of design of the structures through the strength based on the penetration state of the fillet weld. Patterns of fatigue failure in cruciform fillet weld jont appear in the form of the root, toe and mixed failure. In the case of toe and mixed failure, the fatigue strength is higher than root failure. Therefore, we have to make the enough depth of penetration or perform the welding work through improving the fatigue strength of cruciform joints in welded structures. So it is necessary to optimize the penetrated depth in the range of the possible mixed failure and find the way in the cost-effective design to lessen the amount of the welding work.

• Journal of Industrial Technology
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• v.23 no.A
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• pp.131-137
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• 2003

This thesis is results of centrifuge model experiments to investigate the behavior of replacement method in dredged and reclaimed ground. For experimental works, centrifuge model tests were carried out to investigate the behavior of replacement method in soft clay ground. Basic soil property tests were performed to find mechanical properties of clay soil sampled from the southern coast of Korea which was used for ground material in the centrifuge model tests. Reconstituted clay ground of model was prepared by applying preconsolidation pressure in 1g condition with specially built model container. Centrifuge model tests were carried out under the artificially accelerated gravitational level of 50g. Replacing material of leads having a certain degree of angularity was used and placed until the settlement of embankment of replacing material was reached to the equilibrium state. Vertical displacement of replacing material was monitored during tests. Depth and shape of replacement, especially the slope of penetrated replacing material and water contents of clay ground were measured after finishing tests. Model tests of investigating the stability of embankment after backfilling were also performed to simulate the behavior of the dike treated with replacement and backfilled with sandy material. As a result of centrifuge model test, the behavior of replacement, the mechanism of the replacing material being penetrated into clay ground and depth of replacement were evaluated.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.137-140
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• 2008

This experiment states the ultra pure distilled water penetration depth through ray parenchyma cell in radial direction of Castanea crenata. Heartwood penetration depth was 1.16 times lower than the depth in softwood and that difference was found statistically significant at 75.2 second of penetration. Following go-stop-go cycle, water penetrated in the ray parenchyma cell. At the beginning this speed was high and then it was decreased slowly. Water penetration depth result was compared with alcohol penetration depth. It was found that water penetration in ray parenchyma was found lower than alcohol due to the low surface tension of water.

• Journal of the Korea Furniture Society
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• v.29 no.1
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• pp.1-7
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• 2018

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Metasequoia glyptostroboides, diffuse-porous wood Anthocephalus cadamba and ring-porouswood Fraxinus rhynchophylla. In radial direction, ray cells and in longitudinal direction, tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents (MC). The length, lumen diameter, pit diameter, end wall pit diameter and the numbers of end wall pits determined for the flow rate. The liquid flow in the those cells was captured via video and the capillary flow rate in the ones were measured. Vessel in hardwood species and tracheids in softwood was found to facilitate prime role in longitudinal penetration. Anatomical features like the length and diameter, end-wall pit numbers of ray parenchyma were found also responsible fluid flow differences. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Therefore, the average liquid penetration depth in longitudinal tracheids of Metasequoia glyptostroboides was found the highest among all cells considered in Anthocephalus cadamba and Fraxinus rhynchophylla In radial direction, ray parenchyma of Metasequoia glyptostroboides was found the highest depth and the one of Fraxinus rhynchophylla was the lowest. The solution was penetrated lowest depth in the wood fiber of Fraxinus rhynchophylla. The large vessel of Fraxinus rhynchophylla was found the lowest depth among the vessels. The solutin was penetrated to the wood fiber of Anthocephalus cadamba higher than the one of Fraxinus rhynchophylla.

• Journal of the Korea Furniture Society
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• v.28 no.1
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• pp.88-93
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• 2017

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Larix kaempferi (Lamb.)Carriere, diffuse-porous wood Betula davurica Pall.. and ring-porouswood Castanea crenata S.etZ. In radial direction, ray cells and in longitudinal direction, tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents (MC). The length, lumen diameter, pit diameter, end wall pit diameter and the numbers of end wall pits determined for the flow rate. The liquid flow in the those cells was captured via video and the capillary flow rate in the ones were measured. Vessel in hardwood species and tracheids in softwood was found to facilitate prime role in longitudinal penetration. Anatomical features like the length and diameter, end-wall pit numbers of ray parenchyma were found also responsible fluid flow differences. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Therefore, the average liquid penetration depth in longitudinal tracheids of Larix kaempferi was found the highest among all cells considered in Betula davurica and Castanea crenata, In radial direction, ray parenchyma of Larix kaempferi was found the highest depth and the one of Betula davurica was the lowest. The solution was penetrated lowest depth in the wood fiber of Castanea crenata. The large vessel of Castanea crenata was found the lowest depth among the vessels. The solutin was penetrated to the wood fiber of Betula davurica higher than the one of Castanea crenata.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.75-80
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• 2003

Understanding the seawater infiltration into tidal flat sediments is very important, because it is significantly correlated with the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival. However oil blocks interstitial spaces of sediments, reduces seawater infiltration and results in the decrease in oxygen, nutrients and other food supply to benthic communities. The penetration depth of the stranded oil into the sediments is one of the most significant information to know the effect of spilled oil on biological communities and to set up a cleaning method. So we initiated this study to quantify the penetration behavior of spilled oil and to evaluate the influence of the penetrated oil on seawater infiltration in tidal flat environment and its ecological implications. The penetration depth of the crude oil into the tidal flat sediments was two times deeper than that of the fuel oil C, and the depth was significantly affected by stranded oil volume. However, the penetration depth of stranded oil was abruptly dropped at first falling tide but not significantly fluctuated after that. Moreover, hydrocarbon concentration showed the highest within the upper 2 cm. Seawater infiltration was decreased in proportion to the stranded oil volume. The seawater infiltration was more affected by the penetrated fuel oil C about 1.7 times than the crude oil, because the interstitial spaces of the top of sediments were more cleared by the fuel oil C. Therefore, quick cleaning actions for penetrated oil will be necessary for recovery of seawater infiltration because the seawater contains oxygen and nutrients necessary for the survival of benthic organisms in tidal flat.