• Proceedings of the KSEEG Conference
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• 2000.04a
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• pp.124-125
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• 2000

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3723-3728
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• 2011

This study investigated the friction behaviors of rock and grout through the small /large scale laboratory experiments. The small-scale laboratory tests were undertaken using a specially designed and fabricated equipments to simulate the contact surface of rock. In calibration chamber test, a artificial rock mass was prepared in soil container to measure the tensile resistance of grout. Test condition includes the grouting method of pressure involvement. The results of the tests show that the pressure grouting increases the frictional resistance significantly.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.868-870
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• 2009

이 연구에서는 암반에 마이크로 파일을 그라우팅하여 시공할 경우에 암반과 그라우트 접촉면에 발생되는 부착력을 특수 제작된 부착력실험용 몰드와 만능시험기를 이용하여 측정하고 그라우팅 방법(압력식, 중력식)을 달리하여 비교 분석하였다. 실험결과 압력식의 부착력과 일축압축강도가 중력식보다 크게 나타났다.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.45-51
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• 2003

Grouting materials in rock is grouted as vein type along the fault surface by the other way for soil and allow a change of characteristics in rock faults as a result of that. Therefore the deformation characteristics of rock faults after grouting differ as a direction and characteristic of grouted fault and stress condition of field rock. Thereby it must be analyzed the effect for deformation of rock according to characteristics of rock faults and characteristics of grouting materials to accurately evaluate the reinforced effect by grouting. But grouting method used in field until present depends on experience of workers, and inspection for those effects are evaluated by measurement of elastic wave velocity, permeability tests and etc. in field. In this study, it was investigated that the effects for shear characteristics of maximum shear strength, residual shear strength and etc. by comparison and analysis of test results which were worked by direct shear tests of rock faults with changing a type of grouting materials and the grouting depth(t) for average width(a) of fault surface roughness when OPC(Ordinary Portland Cement) and Micro cement was grouted in fault surface of field rock to evaluate characteristicsof the shear deformation for rock fault surface of dam by grouting.

• Tunnel and Underground Space
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• v.25 no.3
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• pp.244-254
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• 2015

The tunnel is excavated through the alluvial layer composed of sand and gravel with groundwater deposited on rock. A portion of upper part of the tunnel is located in the alluvial layer and there are several buildings just above the curved section of the tunnel. It is necessary to prevent from sand-flowing into the tunnel due to low strength of the alluvial, high groundwater level and shallow depth of the tunnel from the ground surface. For this, the alluvial around the tunnel is pre-reinforced by umbrella arch method with multi-stage grouting through large diameter steel pipes or jet grouting before excavating the tunnel. The effect of the pre-reinforcement of the tunnel and the safety of the buildings are monitored by measurement of ground deformation occurred during tunnelling.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.181-186
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• 2022

Dam slope RIM is a highly important contact interface where the main body and the base surface are connected. In general, when the grouting for the slope of the dam structure is designed, it is planned using limited data (drilling, geological map, etc.). This makes it very difficult to accurately consider the original ground characteristics of the slope RIM grouting target, In addition, when the grouting volume planned during the design is drilled and injected into the original ground where the waterstop is secured, there is a possibility that the original ground with the waterstop is disturbed and the effect of the waterstop is rather diminished. In order to overcome such problems, it is more suitable to first consider geological conditions and determine whether to perform optimal grouting on the original ground through on-site repair tests before performing RIM grouting. In this paper, to determine the grouting of the RIM unit, a pilot hole water pressure test was performed on the rock of the slope in the target section. The analysis shows grouting volume of 1 Lugeon or less, and the cement injection amount also shows the injection result of 1 kg/m or less. In this case, performing grouting is rather counterproductive. This result can be evaluated through a rock of which some degree of order of mass is secured, as it is a dam design standard of 1 Lugeon or less when analyzed, using the results of visual observation and geological map creation during slope cutting. Therefore, in conclusion, it is preferable to make the decision for using RIM grouting on the slope of the dam body structure, based on 1 Lugeon in a rock state, and the cement injection amount also at 1 kg/m.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.349-360
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• 2003

A practical modeling approach has been proposed in this study to better understand the behavior of penetration grouting which is normally applied to the jointed rock masses to increase the bearing capacity and to reduce the ground water flow into the tunnel. Based on Bingham model together with a steady-state flow of the grout, penetration model is simulated in the commercial package called UDEC and, injection pressure as well as joint thickness are found to be the main parameters to determine the range of grout spread. Another numerical model on fracturing grouting is also suggested and, in this case, the tensile strength as well as cohesion of the rock masses are proven to be the major factors to decide the fracturing mechanism of the rock masses. The reinforcement effect of the grout-reinforced rock masses is calculated from the suggested algorithm on orthotropic material model and it is found that the directional stiffness of reinforced rock masses is increased up to 3 to 4 times compared with original jointed rock masses. Future work will be concentrated on the water control around the tunnel by the grout injection and a model test will also be performed to verify the suggested methods developed in this study.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.51-59
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• 2009

This study is based on field data obtained from rock grouting such as RQD value, Unit cement grout volume, Lugeon value(Lu), and Maximum grout pressure in four different dam sites. The relationship were analyzed and compared as follow. The cut-off effect after rock grouting in dam-foundation which are mostly consist of metamorphic rock is better than that of Sedimentary rock. And the impermeable effect after consolidation grouting is more efficiency than the impermeable effect after curtain grouting. The unit cement grout volume are increased as RQD value is higher in rock mass. But there is no relationship between RQD value and Lugeon value. In the sedimentary rock, which is more permeable than metamorphic rock, Lugeon value (Lu) is a linear function (Lu=0.22Vc) of unit cement grout volume (Vc). Cut-off effect of curtain grouting is less influential at each near holes which are already grouted than that of consolidation grouting. And the behavior characteristics of Lugeon value vs. the unit cement grout volume as the order of installations are almost the same.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.2
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• pp.145-155
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• 2010

Recently interest in subsea tunnels is increasing nationwide and the construction of a subsea tunnel is taking place. For the stability of such a subsea tunnel, grouting is necessary for the water barrier and reinforcement of the tunnel. In this study, therefore, it was investigated how the grouting reinforcement had an effect on the stability of a subsea tunnel located in a great depth. To this end, Hydro-mechanical coupled analyses were performed for a sensitivity analysis in terms of different grouting range, rock class, shotcrete thickness, coefficient of lateral earth pressure, grouting thickness, and pumping existence for the rock classes I, III, and V. FLAC-2D ver. 5.0 was used for the numerical analyses. It was came to the conclusion that the effect of the increased water pressure due to the water barrier of the grouting should be considered as well as the strength improved effect in designing grouting reinforcement of subsea tunnels.

• The Journal of Engineering Geology
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• v.13 no.4
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• pp.445-456
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• 2003

Backfill grouting and consolidation grouting are major reinforcing methods that enhance the stability of tunnel by filling the gap between the tunnel lining and the ground and increasing the stiffness of the ground. However, the effect of the grouting on the tunnel lining is not well established. Field measurements such as pressuremeter test, Lugeon test, and lining instruments were peformed to analyze the grouting effect on the tunnel lining for a waterway tunnel. The elastic modulus was increased up to 5 times than that of original rock mass due to consolidation grouting. This study shows that only 10% of grout pressure was acting on the back face of the tunnel lining. The final results are expected to be used for the design of the concrete lining.