• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.39-47
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• 2004

The SCP(sand compaction pile) method which is a vertical reinforcing technique for soft ground using a sand compaction pile has received increasing popularity in Korea. Currently, there are different methods to evaluate the bearing capacity of the reinforced ground by the SCP method. However, a method that can consider the effect of the replacement ratio on the bearing capacity is not yet available. This study investigated the effect of the replacement ratio on the bearing capacity of the reinforced ground by the SCP method. The study involved laboratory experiments which were conducted on a centrifuge facility. Test conditions included various ranges of replacement ratios (20, 30, and 40%), centrifuged consolidation, and loading. From the results of the study, a method which can evaluate the bearing capacity of the reinforced ground was proposed and verified using the weighted average of the replacement ratio.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.37-46
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• 2011

An application frequency of vertical drainage method is increasing as an effective consolidation acceleration method. PBD method is most frequently used as a consolidation acceleration method in vertical drainage methods. PBD is economical and easy to operate but has some problems those are an environmental pollution and a decrease of a discharge capacity caused by bending of drainage materials when it is used in great depth. SCP method was frequently used because it's discharge capacity was good but now it is rarely used because of an increase of the material price because of an order imbalance. As the way to solve these problems, GCP method has been to the fore. For analyzing the effect of GCP method on the discharge capacity, three types of composite discharge capacity tests are done by using GCP, SCP and PBD respectively with the circle case, ${\phi}38{\times}h70cm$. On the contrary to this, GCP shows the worst discharge capacity for a decrease of the void ratio and the clogging phenomenon caused by increasing load. Also to figure out the clogging range of GCP, the clogging of GCP is checked in each load stage with a large case($1.0m{\times}0.5m{\times}1.1m$) which has clear acrylic front face. The diameter of GCP was 35cm and a clogging phenomenon occurred in 10% approximately. The result shows that the discharge capacity of GCP was given the lowest value for a decrease of the void ratio and the clogging phenomenon causing by increasing load. And the clogging phenomenon mostly occurred within 10% of GCP's diameter range.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.21-28
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• 2017

The steel-plate concrete(SC) is used in a form of module assembly construction in the outer wall of nuclear-power plant and LNG containment. Since the steel-plate concrete modules are generally manufactured from the plant, the weight of SC has significantly effect on the total construction cost in the aspect of shipment. Therefore, the use of lightweight aggregates concrete(LWAC), which fill the inside of SC module can be a solution. However, the amount of used lightweight aggregates(LWA) is limited in the use of current concrete mixing process due to the concrete quality problems and it also determines the allowable minimum density of LWAC. In this research, the preplaced casting method is applied because of increasing the volume fraction of LWA significantly, which results from the producing process of pre-packing the LWA in the formwork and filling the interstitial voids between LWA using cement paste grout. The density and compressive strength of selected preplaced LWAC were $1,600kg/m^3$ and 30MPa and it was applied for the mock-up specimens of SC panel. It was used for the 3-point bending test for evaluating its structural performance. The results show that the preplaced LWAC can reduce the density of concrete with the adequate mechanical and structural performance.

• Journal of the Korean GEO-environmental Society
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• v.15 no.3
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• pp.5-13
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• 2014

This paper presents the results of a numerical investigation on applicability of Light-weighted Foam Soils (LWFS) consisted of dredged soils for soft ground improvement. The engineering properties of LWFS were comprehensively investigated based on the previous experimental tests. And three dimensional numerical models which reflect soft ground conditions were adopted to evaluate the applicability of LWFS compared to SCP and DCM. A number of cases were analyzed using a stress-pore pressure coupled model. The results indicated that LWFS method enables to reduce more settlement, lateral flow and heaving than SCP method and enable to reduce more residual settlement than DCM method. Also it was revealed that such effect depends on the properties of LWFS such as unit weight, unconfined compressive strength, deformation modulus and Poisson's ratio.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.113-119
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• 2000

This study is to investigate the effects of cold forming method with steel sheet of SCP3C to improve continuous productivity. Experiments were carried out in various working conditions, such as the number of stamping and the punch temperature. The effects of the punch temperature and the number of stamping on drawability of steel sheet of SCP3C as well as clearance and draw-in in tile number of stamping were examined and discussed. The cooled the punch and the die and the blankholder heated by stamping were achieved at continuous productivity and quality improvement. The optimum forming condition for drawing trunk floor panel of SCP3C is shown as the punch is cooled by coolant of $-5^{\circ}C$ and at the same time both the die and the blankholder are heated by stamping and frictional heat,

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.197-205
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• 2005

This paper introduces a new method of improvement for marine soft ground, MLPP (Marine large Pack Pile). The MLPP is a reinforcement technique far the conventional SCP or GCP piles by confining them with geotextile pack. A pilot project at Busan New Port site and laboratory model tests were carried out to investigate the settlement reduction and bearing capacity enhancement effect of pack pile. The results of field and laboratory tests show that MLPP method can be a safe and economic alternative method for SCP and GCP.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.131-137
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• 2008

SCP(Sand Compaction Pile) method that forms a composite ground by driving compacted sand piles into the soft ground. This method is one of the soil improvement techniques for reinforcing and strengthening soft ground deposits. This thesis describes the investigation on the behavior of soft ground reinforced with SCP by low improvement ratio. Direct shear test and consolidation test carried out to verified behavior of composite ground reinforced with SCP. Test results were discussed with reference to the amount of consolidation settlement, variation of shear resistance with area replacement ratio and effect of the stress concentration. And, laboratory model loading test carried out to verified the effect of the location and failure mode of reinforced embankment. Residual shear strength varies with the area replacement and constrict load in the low replacement ratio. Calculated stress concentration ratio overestimate than proposed valve by experimental, theoretical and analytical method. As regards the location, improving right below of the top of the slope was more effective than below of the toe of the slope. This thesis carried out to obtain fundamental information of behavior of the composit ground. Hereafter, centrifuge test that reproduce stress state of the in-situ must be necessary through the further study about pile penetration, reinforce position and construct time.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.187-193
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• 2001

This paper is results of extensive centrifuge model experiments about design factors influencing the bearing capacity and the settlement behaviors of SCP (Sand Compaction Pile). Centrifuge model tests were carried out changing design factors for SCP method such as replacement area ratio (as= 20, 40, 70%), improvement ratio to footing width (W/B = 1, 2, 3), and amount of fines in sand pile (#200 = 5, 10, 15). Therefore, the effects of these design factors on the bearing capacity and the settlement behavior of SCP were investigated and changes of stress concentratio rato due to such an design factors were also investigated. Centrifuge model testing technique for preparing and installing centrifuge model of sand compaction pile, using freezing them, was also developed. As results of centrifuge model tests, more fines in sand compaction pile increases the bearing capacity of SCP. Optimum improvement ratio to footing width was found to be 2. Values of stress concentration ratio was in the ranges of 1.5 - 3.5. The depth of bulging in sand piles was found in the range of 2.0 - 2.5 times of pile diameter.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.145-151
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• 2002

This paper is results of extensive centrifuge model experiments about design factors influencing the bearing capacity and the settlement behaviors of SCP (Sand Compaction Pile). Centrifuge model tests were carried out changing design factors for SCP method such as replacement area ratio (as= 20, 40, 70%), Improvement ratio to footing width (W/B = 1, 2, 3), and amount of fines m sand pile (#200 = 5, 10, 15). Therefore, the effects of these design factors on the bearing capacity and the settlement behavior of SCP were investigated and changes of stress concentratio rato due to such an design factors were also investigated. Centrifuge model testing technique for preparing and installing centrifuge model of sand compaction pile, using freezing them, was also developed. As results of centrifuge model tests, more fines in sand compaction pile increases the bearing capacity of SCP. Optimum improvement ratio to footing width was found to be 2. Values of stress concentration ratio was in the ranges of 1.5 - 3.5. The depth of bulging in sand plies was found in the range of 2.0 - 2.5 times of pile diameter.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.10-18
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• 1996

Experiments were carried out to find the possibility of an economic production of single cell protein(SCP) in mixed culture by Cellulomonas sp. KL-6 and a second organism. The second organism, strain LI-10, was isolated from the large intestines of a mouse. 1. When these strains were mixed, cell growth and carboxymethyl cellulase (CMCase) activity were increased to about 63% and 161%, respectively compared with that of single culture of strain KL-6. We found the mixed culture as a proper method of degradation of cellulose in our study. 2. Strain LI-10 was identified as E. coli. 3. This strain produced trace amounts of cellobiose, but glucose was not found in detectable amounts in the filter paper(FP) medium. 4. $CaCO_3$ injected in the medium at the ratio of 0.1% not only enhanced cell growth but also was effective as an acid neutralizing agent. 5. When this organism was cultured under the optimal medium (glucose 0.1%, $NH_4Cl$ 0.1%, yeast extract 2.0%, $KH_2PO_4$ 0.1%, KCl 0.05%, pH 7.2 and a temperature 30$\circ$C) for 5 days, a cell mass produced 1.18 g/l. The results showed the increase of cell mass up to 300% compared to 0.28 g/l produced in CMC medium.