• Title/Summary/Keyword: Compaction grouting system

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A Study on the Ground Improvement by Compaction Grouting System (C.G.S에 의한 기초지반보강효과에 관한 연구)

  • 천병식;여유현;최현석;오일석
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.02a
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    • pp.1-13
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    • 1999
  • The use of Compaction Grouting evolved in the 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has developed and is currently used in wide range of applications. Compaction Grouting, the injection of a very stiff, 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major uses of Compaction Grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other application include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. The technique replaced slurry injection, or 'pressure grouting', as the preferred method of densification grouting. There are several reasons for the increased use of Compaction Grouting which can be summarized in one word: CONTROL. The low slump grout and injection processes are usually designed to keep the grout in a homogeneous mass at the point of injection, while acceptable in some limited applications, tends to quickly get out of control. Hydraulic soil fracturing can cause extensive grout travel, often well beyond the desired treatment zone. So, on the basis of the two case history constructed in recent year, a study has been peformed to analyze the basic mechanism of the Compaction Grouting and verify the effectiveness of the ground improvement using some test methods.

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A Study on the Ground Improvement by Compaction Grouting System (CGS에 의한 기초지반보강에 관한 연구)

  • 천병식;권형석
    • Journal of the Korean Society for Railway
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    • v.2 no.4
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    • pp.9-19
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    • 1999
  • The use of compaction grouting evolved in 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has been developed and is currently used in wide range of applications. Compaction grouting, the injection of a very stiff, 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major applications of compaction grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other applications include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. In this paper, on the basis of the case history constructed in this year, a study has been performed to analyze the basic mechanism of the compaction grouting. Also, the effectiveness of the ground improvement and the bearing capacity of the compaction pile has been verified by the Cone Penetration Test(CPT) and Load Test. Relatively uniform compaction grouting column could be maintained by planning the quality control in the course of grouting. And, the Qualify Control Plan has been conceived using grout pressure, volume of grout and drilling depth.

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A Study on the Ground Improvement by Compaction Grouting System (C.G.S에 의한 기초지반보강효과에 관한 연구)

  • 천병식;여유현;최현석;오일석
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.375-382
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    • 1999
  • The use of compaction grouting system(C.G.S) evolved in the 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has developed and is currently used in wide range of applications. Compaction Grouting, the injection of a very stiff 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major uses of Compaction Grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other application include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. So, on the basis of the case history constructed in recent year, a study has been performed to analyze the basic mechanism of the Compaction Grouting and verify the effectiveness of the ground improvement.

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An analytical solution for compaction grouting problem considering exothermic temperature effect of slurry

  • Chao Li;Yingke Liu;Man Yuan;Tengrui Yang
    • Geomechanics and Engineering
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    • v.35 no.6
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    • pp.593-601
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    • 2023
  • In this paper, an analytical solution of large-strain cylindrical cavity expansion in compaction grouting problem under temperature field is given. Considering the stress increment caused by temperature, the analytical solution of cavity expansion under traditional isothermal conditions is improved by substituting the temperature stress increment into the cavity expansion analysis. Subsequently, combined with the first law of thermodynamics, the energy theory is also introduced into the cylindrical cavity expansion analysis, and the energy dissipation solution of cylindrical cavity expansion is derived. Finally, the validity and reliability of solution are proved by comparing the results of expansion pressure with those in published literatures. The results show that the dimensionless expansion pressure increases with the increase of temperature, and the thermal response increases with the increase of dilation angle. The higher the exothermic temperature of grouting slurry, the greater the plastic deformation energy of the surrounding soil, that is, the greater the influence on the surrounding soil deformation and the surrounding environment. The proposed solution not only enrich the theoretical system of cavity expansion, but also can be used as a theoretical tool for energy geotechnical engineering problems, such as CPT, nuclear waste disposal, energy pile and chemical grouting, etc.

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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Study on Applicability of Simultaneous Multiple Compaction Grouting Method in Soft Clay Ground (점성토 연약지반에서의 다중 동시주입 컴팩션 그라우팅 공법 적용성 연구)

  • Lee, Hyobum;Jung, Hyun-Seok;Jung, Eui-Youp;Choi, Hangseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.779-788
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    • 2019
  • The compaction grouting method is one of the conventional ground improvement methods, which consolidates and compacts the surrounding ground through the injection of grout materials with low mobility. Injecting the grout into the ground can improve the soil properties, as well as form a composite of soil-grout columns. However, the conventional grout pumping is not applicable to handle multiple injection holes at the same time, which may diminish its constructability when the construction time is not enough. This paper proposes a simultaneous multiple compaction-grouting method using a new pump system developed to cover up simultaneously three injection holes at a time. Field injection tests with a single injection hole and with triangular arrangement of injection holes were conducted to evaluate the applicability of the proposed method to soft clay ground. In addition, a series of standard penetration tests (SPTs) were performed to assess the efficiency of each arrangement in improving the soft ground. It is noted from the in-situ test results that the interval distances between injection holes and the elapse time for ground stabilization are the crucial factors governing the applicability of the simultaneous multiple compaction-grouting method to improve the soft clay ground.

A Reinforcement Effect of Pile Foundation by Compaction Grouting System in Railroad Station Building (Compaction Grouting System에 의한 철도역사건물 파일기초보강효과)

  • Chun, Byung-Sik;Choi, Seung-Kwon;Do, Jong-Nam;Sung, Hwa-Don
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1364-1368
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    • 2006
  • By the countermeasure which is caused by with railroad station ground settlement it applied a CGS in each independent foundation. The effectiveness of the ground improvement and the bearing capacity of the compaction pile has been verified by the Cone Penetration Test(CPT) and Load Test. Test result show that penetration resistance and the cone friction force increased a lot and settlement 13.475mm as the standard settlement 40.0mm appeared at below. Also uniaxial compression test result $278kg/cm^2$ as the standard $150kg/cm^2$ appeared far a lot.

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Development and Reliability Verification of Quality Control System for Compaction Grouting Method (컴팩션 그라우팅 공법의 품질관리 시스템 개발 및 신뢰성 검증)

  • Seo, Seok-Hyun;Lee, Jung-Sang;Jung, Eui-Youp;Park, Sang-Yeong;Lee, Hyo-Bum
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.4
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    • pp.11-20
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    • 2020
  • This study introduced the compact grouting method that can be used for improving soft ground and restoring buildings with unequal subsidence. The pump used in the traditional compact grouting method is a system that injects one hole each, which reduces the construction efficiency, and the analog injection method manually manages the construction by field workers, making it difficult to manage consistent quality. Pump and quality control system were developed to solve problems in existing construction. Since field supervisor determines amount of injected materials by using analog equipment and controls manually, it is difficult to manage consistent quality of construction. Therefore, the quality control system was developed in order to solve that problem. The quality control system consists of automatic mixing system of injection materials, multiple simultaneous injection pumps, and injection management monitoring system. Performance of the quality control system was verified through on-site testing, and ground improvement performance was verified through quality testing after testing and testing of the compact grouting method. Therefore, it is expected that the integrated quality control system developed will improve the quality assurance and efficiency and stability of construction at sites where construction and quality verification are difficult.

Effects of Ground Improvement Depending on the Type of Soil by Compaction Grouting System (토질의 종류에 따른 CGS공법의 지반개량효과에 관한 연구)

  • Chun, Byung-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.3
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    • pp.211-220
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    • 2002
  • CGS(Compaction Grouting System) is widely used in reinforcement of structural foundation and ground improvement in soft ground. But the effects of ground improvement depending on the type of soil must be studied in order to adopt in various soils (granular soil and cohesive soil). In this study, characteristics of ground improvement (the increase of N value, increase in unit weight, vertical displacement on the ground surface) by CGS method was compared through two cases that were performed in granular and cohesive soil. The results show that the closer to the grout hole, the more increase in N value and this trend appear distinctly in granular soil. Unit weight of ground increase largely near by the grout hole and decrease in far from it independently of the soil type. The vertical displacement on the ground surface appeared in smaller area in case of granular soil than cohesive soil.