• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.910-921
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• 2004

In this study, the pilot tests on the reclaimed land were performed in order to find the suitable construction method with dynamic compaction Type I, Type II at different dynamic energy and hydraulic hammer compaction. The estimation of the compaction through the various pilot tests was performed by the CPT-qc, SPT-N and field density tests. As the result of the pilot tests, it shows that the dynamic compaction method is better than the hydraulic hammer compaction method in the effect of the ground improvement, especially dynamic compaction Type I is much superior to others. When it comes to method for measuring the intensity of the ground, the value of the cone penetration test-resistance(qc) is much suitable for the ground. Besides, the standards for the compaction control, which showed that over 10Mpa at 0 through 5meters in the upper layer and 7Mpa at 5 through 8meters in the lower layer in the CPT-qc, could be found without discrimination of the upper road and lower road on the reclaimed land. And it also found that the intensity of the reclaimed land gets back to the original status in about 10 through 15 days.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.7-12
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• 2002

The purpose of this study is to design and to apply the self-compaction concrete mixture to field, having not only high strength but also compensation for shrinkage without thermal crack under 4 sides outer restraint of the member. In the experimental mix, replacement ratio of limestone Powder, CSA expansive additives, and unit water were selected as parameters, using portland blast-furnace slag cement. And, bleeding test, expansibility test, hydration heat analysis were performed. As a results, when Cement is replaced with 35% limestone Powder, 6% CSA expansive additives at unit water 175kg/$m^3$, demanded performances of fresh and hardened self-compaction concrete are accomplished in the field application.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.525-532
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• 2004

Among soft ground treatment methods with granular soil used in domestic, the sand compaction pile method has been utilized greatly, but, as a result of exhaustion of sand and increase of unit cost, a necessity of an alternative method is suggested. In this study, the static load tests for crushed-stone compaction piles which were constructed on test field were performed. Based on test results, stress concentration ratios between the crushed-stone compaction pile and the soft ground were investigated and estimated. The stress concentration ratio was the range of 1.7 to 3.0 and the higher it was the more replacement rate was increased.

• The Journal of Engineering Geology
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• v.26 no.4
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• pp.439-445
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• 2016

The new airports apply the systematic runway foundation construction to build the high quality runways in order to take the leading position to win future aerial demands and stay ahead of competitors. This study is intended to supplement the weakness of existing standard compaction test to minimize residual settlement of lower weak foundation during operation of passenger berthage. The fill material was sampled from 4 construction sites using the fill material with diameter of 100mm or less, and the standard compacting test (KS F 2312), large circular mold compacting test, and water-replacement field density test (ASTM D 5030) were conducted. The regression analysis of correlation of the field density test and the standard indoor compaction test showed the unreliable value at P-value of 0.05, and the regression analysis of the field density test and the large indoor compaction test showed the high correlation with R value of 0.8878. It is judged that the construction of overall uniform quality can be assured as the site condition is truly reflected only if the compacting test method is selected in consideration of maximum size of fill material when evaluating the maximum dry density used in design and construction.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.71-78
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• 2000

In this study, the evaluation for effective utilization of waste landfill was performed by field test to use waste landfill as construction site(Nangido in Seoul). This site had been formed by dredging the household waste, building debris and industrial waste for fifteen years(78'3~93'3). The site where dynamic compaction test was divided by 4 yards. Yard-1, 2 were not eliminated widening of cover soil and Yard-3, 4 were eliminated it. Dynamic Compaction Pilot Test was carried out by the 15ton heavy tamper with drop height of 20m in Yard-1, 3 and with drop height of 15m in Yard-2, 4. We evaluated the compaction efficiency, optimum compaction number and noise vibration through field test, monitoring. As a result, if the countermeasures against vibration and noise by the method utilize, the dynamic compaction method is suitable for using in waste landfill as a construction site among the ground improvement method.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.285-293
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• 2018

In densely populated urban areas with a large amount of infrastructure, ground subsidence events can result in massive casualties and economic losses. In South Korea, the incidence of ground subsidence in urban areas has increased in recent years and the number of underground cavities suspected of causing such events has significantly increased. Therefore, it is essential to develop techniques to prevent the occurrence of underground and ground subsidence. In this study, a field test, laboratory test, and numerical analysis were conducted to determine the optimal compaction degree of the upper support layer of any underground cavity below the level of sewer pipes in order to prevent such cavities from collapsing and leading to ground subsidence accidents. During the field test, an underground cavity was simulated using ice, and the generation of the cavity was confirmed using ground penetrating radar. The ground investigation was performed using a cone penetration test, and the compaction of the ground where ground subsidence occurred was evaluated with a laboratory test. The behaviour of the ground under various conditions was predicted using a numerical analysis based on the data obtained from the field test and previous studies. Based on these results, the optimal compaction degree of the ground required to prevent the underground cavity from causing ground subsidence was predicted and presented.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.84-95
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• 1991

The compaction ratio of the field dry density to the maximum dry density is generally adopted as the index of quality control for embankment of earthfill structures such as Earth Dam, Sea Dike, River Bank and Road. In case of coarse materials are included in the earth material, the compaction ratio will be varied in wide range since the dry density is influenced by quantity of coarse material in the soil. The treatment for the coarse material should be controlled carefully in testing. In this study, the compaction characteristics of the soil contained the coarse materials were researched and calibration of the suitability of field quality control methods were carried out. 28 Samples were made of clay(CL) and sandy soil (SM) mixed with gravel whose content were 0, 4, 6, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, and 60% in Weight. The compaction characteristics depending on the coarse material content were analysed through 4 types of compaction tests which are A-1, B-i, C-i and D-1. The adjusting coefficients for density and moisture content namely a and ${\beta}$ respectively were proposed in order to consider the effects depending on content of the coarse materials. The test methods to control reasonably and promptly the quality of earthfill were proposed after analysing the ranges of possible errors on the relative compaction ratio between laboratory compaction methods and field density testing methods.

• Journal of the Korean GEO-environmental Society
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• v.8 no.6
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• pp.13-19
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• 2007

This study examines a cause for damage of synthetic resins straight pipe occurred after pipe construction of underground electric power duct pipelines of ${\bigcirc}$ section work, ${\bigcirc}$ line, ${\bigcirc}{\bigcirc}$ city railroad. For this, we analyzed a parameter used for plan and structural analysis through a literature review. And the site condition was analyzed in detail, and test construction of the pipe line that simulated the site pipe line and test on compaction by watering were performed. In addition, an examination on subsurface settlement influence of foundation ground through a structural safety and a numerical analysis of power transmission pipe line was performed. As a result of the performance, relative density gained by compaction by watering was more than average and relative degree of compaction according to technical specification standard showed the result of about 90% in the case of good compaction by watering.

• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.5-16
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• 2011

The objective of this paper is to assess the potential use of the resilient force of the ground obtained from an accelerometer and to propose a new compaction control process. Several comprehensive field experimental programs were conducted to analyze the correlation of compaction results obtained from an accelerometer and conventional test methods (e.g. the plate load test and field density test). This study focused on comparing the compaction results obtained from an accelerometer with conventional test results statistically. Based on the statistical analysis results, impact and resilient force measured from an accelerometer, mounted on the drum of a roller are very useful factors for continuous compaction control. A new compaction criteria determination process using an accelerometer is also proposed in this study.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1427-1439
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• 2008

The quality of track-bed fills of railways has been controlled by field measurements of density (${\gamma}_d$) and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures is that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of $OMC{\pm}2%$ as well as the p-wave velocity.