• Title/Summary/Keyword: Large Scale Compaction Test

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The Characteristics of the Composite Ground with Sand Compaction Pile(SCP) using Large Soil Box (대형토조시험을 이용한 모래다짐말뚝이 적용된 복합지반의 침하 및 하중전이특성)

  • Kim, Oo-Seok;Park, Eon-Sang;Kim, Jae-Kwon;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.974-981
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    • 2005
  • Because general laboratory tests for sand compaction pile method including unit-cell test device have fixed outside diameter, as area replacement ratio increase, diameter of sand pile increase. These condition can bring about overestimation of stiffness of composite ground. In addition, existing large soil box which consist of bellows type loading plate can occur serious mistake in checking the amount of drained water because there are additional drainage along the inside wall in device. Overcoming these shortcoming, this paper developed modified large scale soil box consist of piston type load plate. In this study, using this device, series of modified large scale soil box tests were performed, and investigated the settlement and stress transportation characteristics with area replacement ratio in sand compaction pile method.

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The Study of Compaction Characteristics of Cataclasite Fill Material using Large and Standard Compaction Tests (대형다짐시험 및 표준다짐시험을 이용한 파쇄암 성토재의 다짐특성 연구)

  • Jeoung, Jae-Hyeung;Ryu, Sang-Hun;Choi, Dong-Yub;Park, Kwang-Sik;Hwang, Sung-Pil
    • 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.

A Estimation Method of Settlement for Granular Compaction Pile (조립토 다짐말뚝의 침하량 산정기법)

  • Kim, Hong-Taek;Hwang, Jung-Soon;Park, Jun-Yong;Yoon, Chang-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.286-293
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    • 2005
  • In soft ground the settlement criterion usually governs. Therefore, it is very important not only reasonable assessment of the allowable bearing capacity of the soil but also reasonable assessment of settlement. In the previous studies by many other researchers, load concentration ratio and settlement reduction factor are usually proposed for estimating the settlement of granular compaction piles. In the previous studies, the reinforced ground with granular compaction piles is simplified as composite ground and the analysis is performed with in the basis of this assumption. However, the lateral deformation of granular compaction pile could not be considered and only the relative vertical strength between pile and soils could be considered in the analysis. In this study, a method adapting the Tresca failure criterion is proposed for calculating settlement of granular compaction pile. Proposed method can be considered the strength of pile material, pile diameter, installing distance of pile and the deformation behavior of vertical and horizontal directions of pile. In the presented study, large-scale field load test is performed and the results are described. Also, predictions of settlements from the proposed method are compared with the results of the load test. In addition, a series of parametric study is performed and the design parameters are analyzed.

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A Study On The Engineering Properties of Rammed Aggregate and Sand Mixture Piers (쇄석과 모래 혼합다짐말뚝의 공학적 특성에 관한 연구)

  • Chun, Byung-Sik;Kim, Baek-Young;Do, Jong-Nam;Kuk, Kil-Keun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.119-122
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    • 2009
  • The gravel compaction pile method has been used as a soft foundation improvement method because bearing capacity and discharge capacity is excellent. But the discharge capacity decreased when the clogging was generated because the clay penetrate into a void of gravel compaction pile. Accordingly, the purpose of this study is to reduce the clogging generation in gravel compaction pile constructing in the soft ground and take a step to minimize a void of gravel compaction pile. And the proper mixing ratio was determined with the large scale direct shear test performed to get strength and permeability with mixing ratio of crushed stone and sand(100:0, 90:10, 85:15, 80:20, 75:25). As a result of the test, it was showed that internal friction angle was the highest at 85:15 mixing ratio of crushed stone and sand and we can make sure a tendency of internal friction angle's decrease when the mixing ratio of crushed stone and sand passed 15%.

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A Numerical Study on the Prevention of Clogging in Granular Compaction Pile (쇄석다짐말뚝에 발생하는 간극막힘 저감방안에 관한 수치해석적 연구)

  • Jeong, Jaewon;Lee, Seungjun;Park, Nowon;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.1
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    • pp.43-51
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    • 2013
  • Recently, engineering problems such as long-term settlement, differential settlement, and the resultant structural damage, have been frequently reported at construction sites. Use of Sand Compaction Piles(SCP) and Granular Compaction Piles(GCP) are good at remedying existing problems, improving bearing capacity and promoting consolidation. However, such compaction piles have the potential for clogging, which would limit their usability. Investigations into the potential for clogging in SCP, GCP, and GCP mixed with sand has not been thoroughly conducted and is the objective of this current study. Large scale direct shear tests were performed on sections of SCP, GCP, and sand mixed GCP to evaluate bearing capacity. Discrete Element Method analyses were conducted with PFC3D and Finite Element Analyses were conducted with MIDAS GTS to propose an algorithm to help reduce clogging in the granular compaction piles. Results from the large scale direct shear test and multiple simulations suggest a 70% gravel and 30% sand mixing ratio to be optimal for bearing capacity and reducing clogging.

Characteristics for Consolidation and Shear Strength of Bottom Ash Compaction Pile According to Replacement Ratio in Clay (점토지반에 적용된 저회다짐말뚝의 치환율에 따른 압밀침하특성 및 전단특성)

  • Park, Sehyun;Jee, Sunghyun;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.7
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    • pp.57-63
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    • 2010
  • The necessity of effective and economical improvement for soft ground is required more and more as mountains form 70% of country. The soft ground improvement methods for ocean development are sand compaction pile method, displacement method are applied to the soft ground improvement from ocean development pre-loading method, air pressure method, well point method, pack drain method, quicklime pile method etc. Among them, the sand compaction pile method, has many problems such as the economical problem on importing materials due to the lack of sand and destroying the nature while collecting sand. To replace the sand with other alternative materials, a study on the bottom ash compaction pile method because the bottom ash has the similar engineering properties with sand. Therefore, in this study, after compose the complex soil with a replacement rate of 10~80% and a large direct shear test, shear test, consolidation test with replacement rates of bottom ash are performed to estimate whether its shear and consolidation characteristics are suitable for the alternative material of compaction pile method. As a result of test, Shear Strength Parameters tend to be increased in accordance with the increase of replacement ratio of bottom compaction pile, and Settlement Reduction Factor and $t_{90}$ tend to be decreased.

The Influence of Field Compaction Method on the Efficiency of Compaction and the C. B. R. Value (전압방법(轉壓方法)이 전압효과((轉壓效果) 및 C. B. R. 값에 미치는 영향(影響))

  • Chung, Sang;Kang, Yea Mook
    • Korean Journal of Agricultural Science
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    • v.10 no.2
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    • pp.292-309
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    • 1983
  • This study is intended to find out the degree of compaction in field compaction, with soil type, the thickness of soil layer and the number of roller passing through the field density test and the field C. B. R. test by comparing vibration and non-vibration compactions. The results in this study are summarized as follows. 1. When the number of roller passing is few, it shows that the efficiency of the compaction by vibratory compaction is greater than that by non-vibratory compaction, the difference of the compaction ratio between vibratory and non-vibratory compaction is decreased according as the number of roller passing is more frequent. 2. Mechanizing on a large scale it is possible for a large equipment to be able to reach the point of A-1 compact ion method with three to five times of roller passing. To provide for mechanizing on a larger scale it is advisable to fix the standard by the D-2 compaction method. 3. As dry-density increases, the C. B. R. value increases, but the increasing ratio of C. B. R. value showed greater in vibrating compacting. 4. According as the number of roller passing increases, the increasing tendency of the C. B. R. Value is slow and the difference of the C. B. R. value between vibration and non-vibration compaction is large, the C. B. R. value showed greater about 20% in vibration compaction than in non-vibration compaction. 5. In C-5 soil type, with increasing the thickness of compaction, the degree of compaction is decreased. When the thickness of compaction is increased from 20cm to 30cm, the degree of compaction is decreased slowly, while the thickness of the compaction is increased from 30cm to 40cm the degree of compaction is decreased remarkably. Therefore it is advisable to compact the ground under the thickness of 30cm.

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Behaviour of Embankment using Bottom Ash-Tire Shred Mixture (저회(Bottom Ash)와 폐타이어를 활용한 성토구조물 거동에 관한 연구)

  • Lee, Sung Jin;Shin, Min ho;Koh, Tae hoon;Hwang, Seon Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1C
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    • pp.21-31
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    • 2009
  • Based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material (soil) with bottom ash. Therefore, we carried out the field compaction test and performance test of large scale embankment in order to evaluate their suitability for the use of lightweight fill materials. In these tests, we could assess the settlement, earth pressure, stress-strain relation, vibration of large scale embankment which were made with tire shred-bottom ash mixture and the conventional fill material(weathered soil) respectively. The earthpressure and vibration transmission was decreased and the settlement behaviour of the 2 materials (tire shred mixture and weathered soil) was measured similarly under static/cyclic loading condition.

Pullout Resistance of Geogrid Reinforced Soil according to Compaction Degree (흙의 다짐도에 따른 인발저항특성 연구)

  • 주재우;김병욱;박종범
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.11-20
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    • 1999
  • The method which makes the soft ground reinforced by using the geogrid, a kind of geosynthetics has been getting popular and its usefulness also has been increased due to reduction in costs, ease of construction and great exterior view, But the study on the frictional characteristics, which is the important factor in design, between reinforcement and soil is insufficient. In this study, compaction degrees were considered through large-scale pullout tests. As a part of studying on estimation of pullout frictional characteristics between soil and geosynthetics, pullout tests were peformed and from the result of pullout tests, pullout frictional parameters between soil and geosynthetics were obtained and pullout behaviors were learned.

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Behaviour Characteristics of Sand Compaction Pile with varying Area Replacement Ratio (모래다집말뚝(SCP)의 치환율 변화에 따른 거동 특성 연구)

  • 박용원;김병일;윤길림;이상익;문대중;권오순
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.117-128
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    • 2000
  • Sand compaction pile(SCP) is one of the ground improvement techniques which is being used for not only accelerating consolidation but also increasing bearing capacity of loose sands or soft clay grounds. In this study, laboratory model test and large-scale direct shear test were performed to investigate the effects of area replacement ratio of composite ground in order to find out the optimum value of area replacement ratio for the ground improvement purpose. Area replacement ratios of 20%, 30%, 40%, 50%, 60% were chosen respectively in the model tests to study the effects of area replacement ratio on variations of stress concentration ratio, settlement and shear strength characteristics of composite ground. In large-scale direct she4ar tests, area replacement ratios of 20%, 30%, 46% were applied to study their effects on shear strength characteristics of composite ground.

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