• Journal of Environmental Science International
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• v.16 no.6
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• pp.735-743
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• 2007

A grouting method is the way to effectively prevent pollutants from spreading into the ground during the digging process of groundwater. This study, based on the comparative study of grouting methods being generally accepted, suggests various construction methods which are suitable for geological structure as follows: In Jeju Island, it is very likely that rocks may fall in shuttered zones such as cracks, joints, scoria layers, and clinker layers. For this reason, it is recommended that materials be injected from the bottom toward the top, not from the top to the bottom. In the case where the amount of injected materials become too large in the areas of cracks or joints because of high level of permeability coefficient, grouting materials which smeared into surrounding areas may cause unwanted cut in the aquifer of the bottom level. To avoid this, the amount of water should be reduced from the typical water-cement ratio of 1:2, and grouting materials with larger grading should be used. If the deep excavation of ground is made in Jeju Island, it is likely to have lots of voids because of geological characteristics. Based on the results of this research, it is found that to construct interior casing, the centralizer should be attached to the casing to prevent the casing from being in contact with the counter fort. The grouting in Jeju Island should be thicker than usual. To avoid over-use of grouting materials, to prevent grouting in more than necessary zone, and to facilitate grouting of void areas, the flexible selection of materials is required. And, to exactly figure out the interior of dug well, an examination through CCTV should necessarily be performed when grouting work is in progress.

• Geomechanics and Engineering
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• v.12 no.5
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• pp.771-783
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• 2017

Using a transparent fracture replica with aperture size and water-cement ratio (w/c), the factors affecting the penetration behavior of rock grouting were investigated through laboratory experiments. In addition, the waterproof efficiency was estimated by the reduction of water outflow through the fractures after the grout curing process. Penetration behavior shows that grout penetration patterns present similarly radial forms in all experimental cases; however, velocity of grout penetration showed clear differences according to the aperture sizes and water-cement ratio. It can be seen that the waterproof efficiency increased as the aperture size and w/c decreased. During grout injection or curing processes, air bubbles formed and bleeding occurred, both of which affected the waterproof ability of the grouting. These two phenomena can significantly prevent the successful performance of rock grouting in field-scale underground spaces, especially at deep depth conditions. Our research can provide a foundation for improving and optimizing the innovative techniques of rock grouting.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.399-406
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• 2004

This paper is experimental study on the effect of improved soil strength which was grouted by pressure grouting method for prevent collapse the tunnel's face during excavate tunnel. This study performs to investigate the proper grouting pressure and grouting method through pressure grouting laboratory model tests using loose dense sandy soil using specially designed and fabricated device($180cm{\times}220cm{\times}300cm$) under changing condition of injection in this test The investigation is carried out through measuring the size and shape of grout bulb, elastic modulus by pressure-meter test Elastic modulus was estimated using relation stress with strain which is result the uni-direction compressive strength test for cured grouted bulb under water during 28days. From these test results, the amount of increased elastic modulus of grouted zone was suggested.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.323-330
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• 1999

Daylight collapse have been occurred by about 5.0m deep at ground surface and collapse of the crown head part of the tunnel have connected to the ground surface during first step of shotcrete work after blasting of upper half section of the tunnel driving at two-way double track tunnel face section on highway construction. This study is for a successful illustration case for the earth improvement method through applying such strengthening methods as cement milk grouting, S.G.R grouting,, steel pipe reinforced multi-step grouting etc. for the purpose of earth strengthening of loosened earth block occurred by tunnel collapse.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.91-96
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• 1996

• Economic and Environmental Geology
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• v.45 no.3
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• pp.307-315
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• 2012

In this paper, a laboratory model test was conducted to evaluate grouting efficiency of ordinary portland cement(OPC) and micro cement used in MIS(Micro-Injection Process System). For this research, a injection equipment was developed for pressure permeation which can evenly simulate various grouting tests in a laboratory and suggested a standard for the production of the test specimen. Using the injection device, the laboratory injection tests of grouts were prepared with water/cement ratio of 1:1, 2:1, 3:1, 4:1, and 5:1. The analysis of injection test for pressure permeation showed that the efficiency of injection increases linearly as the water/cement ratio increases. Comparison of efficiency of the injection indicates that MIS with a relatively smaller average diameter shows more efficient injection than the OPC. In the low ratio of water/cement as 2:1~1:1, the injection efficiency of OPC was especially poor. Also, a nonlinear grout volume-injection time is represented by a hyperbolic model and grout volume predicted by hyperbolic model was compared with the value measured. From the comparison, it shows that the hyperbolic model has the potential of evaluating the efficiency of grouting.

• 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.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.154-163
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• 2009

The groutability depends on the properties of the grout, its injection processes, and on the mechanical properties of the soil formation. During the process of pouring cement-based grouting into a porous medium, a variation with time occurs in the viscosity of grout suspension. In addition the particle filtration phenomenon will limit the expansion of the grouted zone because cement particles are progressively stagnant within the soil matrix. In this paper, a closed-form solution was derived by implementing the mass balance equations and the generalized phenomenological filtration law, which can be used to evaluate the deposition of cement-based grout in the soil matrix. The closed-form solution relevant to a particular spherical flow was modified by a step-wise numerical calculation, considering the variable viscosity caused by a chemical reaction, and the decrease in porosity resulting from grout particle deposition in the soil pores. A series of pilot-scale chamber injection tests was performed to verify that the developed step-wise numerical calculation is able to evaluate the injectable volume of grout and the deposition of grout particles. The results of the chamber injection tests concurred well with that of the step-wise numerical calculation. Based on the filtration phenomenon, a new groutability criterion of cement-based grout in a porous medium was proposed, which might facilitate a new insight in the design of the grouting process.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.747-756
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• 2023

Purpose: In this study, a grout material mixed using non-alkaline silica-based materials, which is an eco-friendly injection material to stabilize ground, is investigated to improve conventional problems. Method: The homogel specimens of Eco-Friendly Non-Alkaline Silica Sol (ENASS) and L.W. and S.G.R., representative silicate grouting are manufactured. Physicochemical and engineering properties of the specimens are evaluated in laboratory with uniaxial compression strength, hydraulic conductivity, shrinkage, chemical resistance, elution, fish poison, waste leaching. Result: Laboratory test results show that the ENASS was superior in all aspects compared to the existing injection matirial. The suitability of the grout material with ENASS is investigated with filed tests. Conclusion: The results of laboratory and field tests demonstrates that the grout material with ENASS is eco-friendly material that increases the strength, decreases the permeability, and discharges pollutants without leaching.

• Geomechanics and Engineering
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• v.38 no.5
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• pp.477-486
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• 2024

The process of inspecting and replacing cutting tools in a shield tunnel boring machine (TBM) is called cutterhead intervention (CHI) (Farrokh and Kim 2018). Since CHI is performed by a worker who enters the chamber in TBM, the worker is directly exposed to high water pressure and huge water inflow, especially in areas with high ground water levels, causing health problems for the worker and shortening of available working hours (Kindwall 1990). Ham et al. (2022) proposed a method of reducing the water pressure and water inflow by injecting a grout solution into the ground through the shield TBM chamber, and named it the new face grouting method (NFGM). In this study, the TBM mechanical characteristics including the injection pressure of the grout solution and the cutterhead rotation speed were determined for the best performance of the NFGM. To find the appropriate injection pressure, the water inflow volume according to the injection pressure change was measured by using a water inflow test apparatus. A model torque test apparatus was manufactured to find the appropriate cutterhead rotation speed by investigating the change in the status of the grout solution according to the rotation speed change. In addition, to prove the validity of this study, comprehensive water inflow tests were carried out. The results of the tests showed that the injection pressure equal to overburden pressure + (0.10 ~ 0.15) MPa and the cutterhead rotation speed of 0.8 to 1.0 RPM are the most appropriate. In the actual construction site, it is recommended to select an appropriate value within the proposed range while considering the economic feasibility and workability.