• Title/Summary/Keyword: Grouting method

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Characteristics of Ground Improvement by Compaction Grouting System in Filled Ground (매립토층에서 CGS에 의한 지반개량특성에 관한 연구)

  • 천병식;여유현;정영교;정완균;정의원;김우종
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.425-432
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    • 2001
  • Compaction Grouting System, the method which makes ground compact by injection of low slump mortar, Is widely used for reinforcement of soft ground, restoration of structures happened differential settlement, underpinning and restoration of damaged dam core. The quantitive analysis of ground improvement for this method has not performed yet. So, design parameters about thls method must be studied through performance of CGS in various types of soil to make CGS adaptable widely. In this study PBT, SPT and field density test were performed for analysis of the characteristics of ground improvement and pressuremeter and inclinometer were installed for analysis of the characteristics of compaction in adjacent ground. In this paper, denoted much effects for filled ground that increasing of the bearing capacity, confirming the displacement of adjacent ground and the effective radius of injection.

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Analysis of the Physical Properties of Ground before and after Low Flowing Grouting (저유동성 그라우팅 시공전후 지반의 물성변화 분석)

  • Seo, Seok-Hyun;Lee, Jung-Sang;Kang, Won-Dong;Jung, Euiyoup
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.4
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    • pp.115-127
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    • 2019
  • The low-flow grouting injection technique, the target construction method for this study, is a method of pouring mortar into the ground by non-emission replacement principle, which can be expected to increase the density of the ground, and, in some cases, be used as a base file using the strength of the high injection solids, along with low noise, low pollution, and high durability. To verify that the dynamic characteristics of the ground are improved by the low-flow injection technique, the test work was conducted on the site and physical tests were performed, and the quality of the improvement formed in the ground was verified through the indoor test on the core and core recovery rate was analyzed. The density logs test layer calculated the volume density of the ground layer by using the Compton scattering of gamma-rays, and the sonic logs was tested on the ground around the drill hole using a detector consisting of sonar and receiver devices inside the drill hole. As a result of the measurement of the change in physical properties (density and sonic logs) before and after grouting, both properties were basically increased after infusion of grout agent. However, the variation in density increase was greater than the increase in speed after grouting, and the ground density measurement method was thought to be effective in measuring the fill effect of the filler. Strength and core recovery rates were measured from specimens taken after the age of 28 days, and the results of the test results of the diffusion and strength test of the improved products were verified to satisfy the design criteria, thereby satisfying the seismic performance reinforcement.

A Study on the Permeability Reduction Methods of the Riverbed Ground during Urban Railway Tunnel construction (도시철도터널공사 시 하저통과구간의 지반투수저하 공법에 대한 연구)

  • Kim, Joon-Jeong;Cho, Kook-Hwan;Lee, Jun-Seok
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.551-557
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    • 2007
  • This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. Firstly, the various grouting methods are theoretically reviewed and compared based on the previous research papers and case study results. It is also evaluated the grouting methods in view of a safe construction of the river crossing railway tunnel. Baced on the literature review and previous construction data, the design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, is suggested. Two injection methods namely, Natural Durable Stabilizer(N.D.S) and Space-Multi Injaction Grouting(S.M.I) methods, are introduced as new approach methods which can be adopted to modify the riverbed ground. In order to evaluate the ground that grouted and modified by the N.D.S and S.M.I method, the pilot test programmes including the field and laboratory permeability tests, are carried out in the river crossing tunnel construction sites. The results obtained from pilot test programme, are also reviewed. In conclusion, the grouting efficiency of the S.M.I method using the non-alcalimeter silica sol is better than that of NDS method using cement. In addition, it hopes that the research results are contributed to develop the grouting design technology.

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The Application and Geo-Enviromental Effect on TAS Method (TAS공법의 적용성과 지반환경 영향)

  • Chun, Byung Sik;Yeoh, Yoo Hyeon;Baik, Jung-Shik;Choi, Choon-Sik
    • Journal of the Korean GEO-environmental Society
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    • v.3 no.3
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    • pp.27-36
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    • 2002
  • Generally, it is known that urethane injection is excellent in long-term durability and environment friendly for ground improvement. However, urethane grouting has short rise time thus the penetration distance from the injection point is so short. Therefore, urethane injection cannot be used for the site where requires ground improvement in deep location from the injection point. Other injection materials such as cement cannot be alternatives when rapid hardening is required. From this study, we improve disadvantage urethane injection by developing TAS method. From the field tests, it is ascertained that TAS increases injection distance over 10m, which is further than that of original urethane grouting. In addition, TAS has relatively short Rise-time compared to cement grouting thus instantaneous improvement can be mobilized right after the injection. Short Rise-time and long penetration distance provide excellent applicability for tunnel construction.

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Evaluation of Axial Bearing Capacity of Waveform Micropile by Centrifuge Test (원심모형실험을 통한 파형 마이크로파일의 연직 지지력 평가)

  • Jang, Young-Eun;Han, Jin-Tae;Kim, Jae-Hyun;Park, Heon-Joon;Kim, Sang-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.31 no.8
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    • pp.39-49
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    • 2015
  • In this study, a series of centrifuge tests were performed in order to observe the bearing capacity of waveform micropile, a new concept of micropile that uses a modified jet grouting process. A total of six models were considered, conventional micropile, jet grouted pile, and four different shapes of waveform micropiles. The test results indicated that the waveform micropile effectively contributes to the increase of the bearing capacity compared to the micropile without the shear keys. Among the waveform micropiles, the model that has a relatively small space between the shear keys showed the most significant improvement of load capacity. Additionally, the ultimate load capacities of all piles were compared using well-known estimation method. As a result, P-S curve method and total settlement method with 25.4 mm were considered suitable to account ultimate load for the waveform micropile.

A Applicability Study on Single Grouted Column Method (C-RJP Grouting) for Buoyancy-Resistant Permanent Anchor in Highly Permeable Volcanic Clastic Zones (투수성이 높은 화산쇄설층에서 부력앵커 시공을 위한 단일공 차수공법 (C-RJP Grouting)의 적용성에 관한 연구)

  • Jung, Yonggun;Chae, Youngsu;Park, Byunghee;Kim, Jeongryeol
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.8
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    • pp.5-12
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    • 2015
  • In this study, buoyancy-resistance permanent anchor was considered to prevent uplift pressure of a building structure. However, this test was failed to put anchor body in the boring hole because of the rapid outflow of ground water and coefficient of permeability. In addition, the hole where the anchor body was forcefully inserted constantly flew the sea water and cement. And it was found that anchor was not settled in the ground. In order to solve this problem, jet grouting method was applied to block the ground water and the single grouted column method was chosen to install the buoyancy-resistance permanent anchor. In this paper, the single grouted column method was applied with the general jet grouting methods and grout material was fixed by 3-field tests. These tests confirmed the effect of permeability and ground improvement with field permeability test by core sampling, Standard Penetration Test (SPT) and unconfined compression test. Confirming the stability of the buoyancy-resistance permanent anchor with installation and tension test, application of the single grouted column method in the volcanic clastic zones was verified.

Design Method for Micropiles (마이크로파일의 설계법)

  • 김원철;천병식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.11a
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    • pp.1-26
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    • 2002
  • This study addresses preliminary design and construction specification for micropiles. Especially several design methods for micropiles in sands, clays or mixed soil layers are described. The bearing capacity of micropiles are mainly depended upon the shaft resistance. Therefore, the pressure of grouting is one of the most important design parameters for the bearing capacity evaluation of micropile. There is no theoretical way to evaluate the shaft resistance of micropile up to now because grouting method is another key parameter for micropile design approach. Because of above reasons, the present design approaches of the micropile are based on the collected field data The bearing capacities of designed micropiles should be verified by static load tests before and after construction at the planned site.

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New deep mixing method installed automatic control equipments (자동제어장치가 장착된 최첨단 심층혼합고결처리공법에 관한 연구)

  • 한우선;조기호;임우성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.847-852
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    • 2003
  • The purpose of this paper is to develop the new deep mixing method installed automatic control equipments for the better construction in deep mixing and grouting. Civil, geotechnical, electronic, and communication experts have worked together for a long time for the development of automatic measuring devices using wire and wireless transmitting-receiving set. A series of laboratory and field experiments were carried out to check the reliability and field applicability of this system. New total automatic control system including automatic devices for checking angle, depth and quantity of injected grout was invented from the result of this research.

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