• Geomechanics and Engineering
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• v.29 no.4
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• pp.391-405
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• 2022

A newly proposed grouting simulation method, the sequential diffusion solidification method was introduced into the numerical simulation of combined bi-borehole grouting. The traditional, critical and difficult numerical problem for the temporal and spatial variation simulation of the slurry is solved. Thus, numerical simulation of grouting and blocking of flowing water in karst conduits is realized and the mechanism understanding of the combined bi-borehole technology is promoted. The sensitivity analysis of the influence factors of combined bi-borehole grouting was investigated. Through orthogonal experiment, the influences of proximal and distal slurry properties, the initial flow velocity of the conduit and the proximal and distal slurry injection rate on the blocking efficiency are compared. The velocity variation, pressure variation and slurry deposition phenomenon were monitored, and the flow field characteristics and slurry outflow behavior were analyzed. The interaction mechanism between the proximal and distal slurries in the combined bi-borehole grouting is revealed. The results show that, under the orthogonal experiment conditions, the slurry injection rate has the greatest impact on blocking. With a constant slurry injection rate, the blocking efficiency can be increased by more than 30% when using slurry with weak time-dependent viscosity behavior in the distal borehole and slurry with strong time-dependent viscosity behavior in the proximal borehole respectively. According to the results of numerical simulation, the grouting scheme of "intercept the flow from the proximal borehole by quick-setting slurry, and grout cement slurry from the distal borehole" is put forward and successfully applied to the water inflow treatment project of China Resources Cement (Pingnan) Limestone Mine.

• 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.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.73-80
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• 2009

This paper is to investigate effect of B.G.I (Best Grouting Innovation) method on reinforcing ground. In this thesis, extensive literature review was performed to summarize theoretical backgrounds of grouting and to compare the applicability of different grouting methods. Unconfined compression test with specimen prepared by injecting different grouts of B.G.I, S.G.R and L.W methods and by changing the curing time were carried out to figure out characteristics of initial unconfined compression strength mobilized in the early stage. As results of test, the compression strength increases with curing times and specimen prepared with grouts of B.G.I method show greater values than others. On the other hands, the measured values of pH are in the range of 7-10 during tests. In field, preliminary construction to main construction at several sites were performed to confirm the effect of reinforcing the ground by application of B.G.I method. From the results of permeability test in field, SPT test and phenol reaction test, it was found that N values after grouting are greater than those before grouting and values of permeability in grouted ground is reduced significantly.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.4
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• pp.409-415
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• 2020

Low-flow mortar injection method grouting technology was selected and the traffic area was preserved as much as possible in order to secure safety for road traffic when the outflow and subsidence of landfill occurred due to ground-water, and etc. In particular, the current existing method was newly improved since there are risks of damage such as hydraulic fracturing at the lower part of the road, spilling of soil particles on steep slopes, and bumps on the road due to excessive injection pressure during construction. This study was carried out at the site of reinforcement work on the road as a maintenance work for the danger zone for collapse of the steep slope of the 00 hill, which was ordered from the 00 city 00 province. The improved low-flow mortar type grouting method adopted a new automated grouting management system and especially, it composites the method for grouting conditions decision by high-pressure pre-grouting test and injection technology by AGS-controlled and studied about grouting effect analysis by using new technology. By applying the improved low-flow mortar type grouting method, it was possible to lay the groundwork for road maintenance work such as the prevention of subsidence of old roads, uneven subsidence of buildings and civil engineering structures, and of soil leakage of ground-water spills. Furthermore, the possibility of application on future grouting work not only for just construction that prevents subsidence of old roads but also for various buildings and civil engineering structures such as railroads, subways, bridges, underground structures, and boulder stone and limestone areas was confirmed.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.368-375
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• 2009

This paper describes field installation and load test results performed for three types of micropiles in the process of developing a new micropiling method. Field tests were performed for two conventional types(i.e., micropile reinforced with steel bar and gravity grouting, micropile reinforced with steel bar and steel casing and gravity grouting) and a proposed type(i.e., micropile reinforced with hollow steel pipe wrapped with geotextile-pack and pressurized grouting). The load test results subjected to axial compression and tension and lateral loading conditions are described in this paper. The micropiles were exposed in the air in order to verify the installation quality and curing condition of grouting material via ground excavation. Axial compression and tension test results indicate that the new micropile type provide at least 40% higher bearing capacity than that of conventional types. Based on the examination of exposed piles, it is induced that the proposed method, packed micropile, provides better interlocking between grouts and surrounding soils and increases higher frictional resistance comparing to conventional types.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.79-87
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• 2011

This study conducted the research on the method of grouting quality management and the improvement effect by applying grouting construction's quality management technology to automatic injection management equipment through measure of liquefaction based on the case of reinforcement applying grouting at the region where liquefaction happened at section 12 site of highway construction. The pressure(p), speed(q), grouting penetration radius(R) value from injection pressure, injection speed, characteristics of grain size, and characteristics of viscosity through p-q-t chart analysis was applied to the automatic grouting system which could improve the quality management of grouting. Standard penetration test results after injection showed that N values represented 5-20 and the prevention of liquefaction became possible.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.02a
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• pp.1-11
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• 2000

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 liquefation, 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 Quality Control Plan has been conceived using grout pressure, volume of grout and drilling depth.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1063-1068
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• 2008

When construction of high pressure jet-grouting is to be performed, it has been reported that applied cement slurry which hasn't got dried out can cause severe environmental pollution, and can flow into near streams and fish farms. Several laboratory tests were performed in this study in order to verify safety of paste-like grouting material that was developed newly to be applied to void in the ground. According to experimental test results, it is proved to be so safe that application of the newly developed flowable grouting material can prevent the materials from spilling into surrounding areas and is not harmful to fishes.

• 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.