• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.382-389
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• 2002

Recently, auger-drilled piling has been widely used in urban area to reduce the air pollution and noise. But this construction method that its basic theory was introduced from Japan may be changed depending on the each piling company and construction field condition. Therefore, the design code and management method for auger-drilled piling is not defined yet. Especially, the lack of research on the bearing capacity of auger-drilled piling leads to the absence of rational bearing capacity prediction equation. This paper presents the optimum design code and economical construction method of the auger-drilled piling by proposing the new bearing capacity prediction equation based on the site specific soil types and construction conditions. In this paper, existing bearing capacity prediction equations and current pile load tests were compared. And the end bearing capacity and skin friction characteristics were also analyzed by comparing the results of CAPWAP. From the results of analysis, a reliable bearing capacity prediction equation considered soil types is proposed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.63-67
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• 2004

A field pilot study on remediation of diesel-contaminated soil by hot air injection/extraction process constructing soil piling system was conducted to evaluate the effects of hot air on the removal of diesel and each constituent. After the heating process of 2 months, the equilibrium temperature of soil reached to 10$0^{\circ}C$ and soil TPH concentration was reduced to about 72% against the initial concentration. Additional extraction process of 2 months induced the continuous extraction of residual diesel and the increment of microbial activity, which made soil TPH concentration reduced to 95%. In addition biological removal of non volatile constituents in diesel was verified indirectly and the removal pattern of each DRO(diesel range organic) as soil temperature was explained.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.163-170
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• 2005

In this paper, the rock bolts, soil nails with filling grout and the micro-piling with injecting grout by pressure were applied for the stabilization of the cut slopes consisting of sedimentary rocks, igneous rocks and metamorphic rocks respectively. The field measurements and 3-D FEM analyses to find out mobilized tensile stresses of the grouted-reinforcing members installed in the drilled holes were executed on each site. With assuming the increments of the cohesive strength in the improved ground, the back analysis using direct calibration approach of changing the elastic modulus of the ground was used to find out the improved elastic modulus which yields the same tensile stresses from field measurements. The results of back analysis show that the elastic modulus of the improved ground were 4 to 6 times as large as the elastic modulus of original ground. Consequently, the design for slope reinforcement to be more rational, it is proposed that not only the improved cohesive strength is to be used in the incremental ranges on well-known previous proposed data, but also the increased elastic modulus which is about 5 times as large as the original elastic modulus is to be considered in design.

• Journal of the Korean GEO-environmental Society
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• v.2 no.2
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• pp.41-50
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• 2001

In this study, for the stability analysis of marine embankment, the slope stability analysis and possibility of lateral movement with the marine embankment in ${\bigcirc}{\bigcirc}$harbor were carried out. In order to simulate the practical site condition, the expected maximum sea water level and maximum embankment height were assumed for these analyses. For the evaluation of soil properties, field test, laboratory test, and especially chemical composition analysis were performed for the this analysis. Based on these test results, the soil parameters were determined by applying ground improvement concept under columnar stabilized ground condition and also the effect of staged backfilling was considered under the dredged ground condition. For the optimal design, the stability analyses of embankment with changed height and unchanged height were performed under unimproved soil condition. The result showed that both cases were unstable not only with slope stability but also with lateral movement. Therefore, Deep Mortar Piling was applied for stability analysis and this result was safe. As the conclusion, the deep mortar piling method was suggested as reinforced foundation design for this site.

• Journal of the Korean Society of Safety
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• v.28 no.5
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• pp.35-40
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• 2013

Recently reclamation land is largely developed to utilize the land according to economic growth. The soil of landfill is soft, low shear strength, which makes it difficult to use the equipment. A large movement is occurred on the utility tunnel under construction. The inclined land with high water level and underground facilities are widely distributed and the excess pore water pressure may occur under construction similarly to this study. Some different conditions are made to design result, such as 4m of soil piling near the construction area, heavy rainfall during 2nd excavation that may cause flow liquefaction. To analyze the cause of transverse lateral movement, Three dimensional analysis are performed to four load cases, which is original design condition, flow liquefaction by heavy rainfall, unsymmetric lateral soil pressure, and both of them simultaneously. Ten steps of full construction stage, 1st excavation for utility tunnel, construction of utility tunnel, 1st refill, piling soil from 1m to 4 m, 2nd excavation for drainage culvert, liquefaction around the utility tunnel, construction of drainage culvert and 2nd refill, are take into account to investigate the cause of movement.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.231-238
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• 2000

Sand piling method is one of the most widely used methods to improve soft soils. There are several methods to install sand piles, but driven pile method is considered as one of the easiest method. This method simply pushes down the sand piles into soft soils, so that the excess pore pressure would be generated if the soil is saturated. This pore pressure acts as consolidation load. If the amount of sand pile induced pore pressure can be predicted in reasonable ways, the effects of sand piling to improve soft soils would be predicted, and the height of preload can be reduced. In this article, sand pile induced excess pressure was predicted by cavity expansion theory, and the predicted values were compared with the field measured values. The results showed fair agreements between the measured and the predicted excess pore pressure.

• Geomechanics and Engineering
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• v.34 no.4
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• pp.397-408
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• 2023

Pipe pile walls are commonly used as retaining structures for excavation projects, particularly in densely populated coastal cities such as Hong Kong. Pipe pile walls are preferred in reclaimed land due to their cost-effectiveness and convenience for installation. However, the pre-bored piling techniques used to install pipe piles can cause significant ground disturbance, posing risks to nearby sensitive structures. This study reports a well-documented case history in a reclamation site, and it was found that pipe piling could induce ground settlement of up to 100 mm. Statutory design submissions in Hong Kong typically specify a ground settlement alarm level of 10 mm, which is significantly lower than the actual settlement observed in this study. In addition, lateral soil movement of approximately 70 mm was detected in the marine deposit. The lateral soil displacement in the marine deposit was found to be up to 3.4 and 3.1 times that of sand fill and CDG, respectively, mainly due to the relatively low stiffness of the marine deposit. Based on the monitoring data and site-investigation data, a 3D numerical analysis was established to back-analyze soil movements due to the installation of the pipe pile wall. The comparison between measured and computed results indicates that the equivalent ground loss ratio is 20%, 40%, and 20% for the fill, marine deposit and CDG, respectively. The maximum ground settlement increases with an increase in the ground loss ratio of the marine deposit, whereas the associated influence radius remains stationary at 1.2 times the pipe pile wall depth (H). The maximum ground settlement increases rapidly when the thickness of marine deposit is less than 0.32H, particularly for the ground loss ratio of larger than 40%. This study provides new insights into the pipe piling construction in reclamation sites.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.763-773
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• 2004

This paper suggests the 2 D.O.F mathematical model of the High Frequency Vibro-Hammer (HFVH), introduces an experimental method for measuring of the attenuation of piling vibration and proves what experiments are coincident with the equation of wave propagation. As vibratory installation of piles and casings has many economic merits in the construction field, most of all contractors prefer to vibratory pile driving method than the other. Compared to impact pile driving, vibratory installation has the advantage of reducing vibration or noise pollution and can drive piles under high frequency. Experiments serve estimations of capabilities and limitations of the HFVH's excitation force and finding of sensitivity for important soil resistance parameters. Also, we discuss the HFVH that can drive with three kinds of input waves (triangular, sine and square wave) and propose the design of parameters to improve actuating performance in it.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.405-414
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• 1999

The auger and screw piles have known an important evolution during the last decade. Besides the large success of augercast (CFA) piling systems, new systems have been developed combining, to a variable extent, the classical extraction auger with especially designed displacement tools in order to develop screw piles with partial or total lateral soil displacement. These last developments cover the whole range of lateral soil displacement and are more difficult than ever to compare. The authors present the latest evolutions in auger piling systems and compare them with respect to penetration performances, bearing capacities and amount of spoil generated. A special focus is given to a new efficient system: the OMEGA(H) pile in use in Korea since 1997. The results of the Hongcheon site are presented where this R system was applied for a new investment of the Korean National Housing Corporation (KNHC). This first important experience, with the execution of some 1,500 Omega piles with diameter 410 mm, is presented. The piles were installed through loose silty sands down to very dense sands and layers of gravel. The results of full-scale load tests are analysed and show the conformity with requirements of the clients.

• Journal of Animal Environmental Science
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• v.10 no.3
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• pp.175-182
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• 2004

A study was conducted to develop a management policy of animal waste in Northern Chungbuk province through investigating the status of animal waste management. In management of swine manure, rotary composting including a simple piling method has a portion of $64\%$ using as a liquefied fertilizer $18\%$, purification $9\%$ and ocean dumping $9\%$ respectively. Most of them use the animal waste as a fertilizer to the agricultural land. The exercise ground of dairy farms was bedded with $70\%$ of sawdust and $30\%$ of conventional soil ground besides the stall. They had a storage tank for the waste water from milking parlor. Korean beef cattle farms mostly run sawdust stall, which changed new one in a term of 6$\~$12 months. In case of layer, manure management was conducted in the order of simple piling method, rotary composting and ventilation into the piling mostly. Comparing the amount of excreted animal manure with that of possible spreading, the latter can be spread more than 2.9 times than the former in Northern Chungbuk province. The Northern Chungbuk province is an appropriate place to carry out an environmentally friendly animal production. An utilization model as a liquefied fertilizer should be developed for paddy field, upland field, orchard, and forage field to in-crease the value of animal waste effectively.