• KCI Concrete Journal
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• v.14 no.1
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• pp.8-14
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• 2002

This is the first of two part series on experimental studies of grout type transverse joints. In this study, grout type transverse joints between precast concrete slabs are statically tested to determine the cracking loads and ultimate shear capacities of the grout type transverse joints. The tests are performed with a loading equipment designed and constructed especially in the lab to induce shear failures on the joints of the test specimens. Shape of the transverse joints, grouting materials and amount of prestress are selected as test parameters for the study. The results indicate that epoxy is an excellent grouting material which can be used in limited locations where large tensile stress is acting on the slab. Longitudinal prestressing is also an effective method to increase the shear strength of the transverse joints. A rational method to estimate the cracking and ultimate loads for the design of grout type transverse joints is proposed based on the static loading tests. Success of the tests with shear loading equipment allowed continuing the research further onto the fatigue strength of the grout type joints, which will be presented in the second part of the paper.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.79-82
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• 2006

This paper presents to examine the ability of an electrical resistivity method to monitor the grouting effect at subsidence area. To monitor the changes in ground resistivity before and during the grout, series of electrical resistivity monitoring surveys have been conducted. Data has acquired in the form of grid making nine lines parallel to road and four lines traverse the road. Two kinds of electrode arrays modify pole-pole and dipole-dipole arrays were used during resistivity data acquisition. In this paper, the results show that electrical prospecting is an effective method to detect low resistivity imaging zone by grout during the ground reinforcement.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.181-196
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• 2001

지하구조물에 있어서 누수사고의 빈번한 발생 및 상습화 경향에도 불구하고 현재 국내에서 사용되고 있는 누수보수방법은 누수유형에 관계없이 일괄적으로 동일한 처리방식으로 보수하는 상황으로서 지하구조물 누수에 대하여 누수 유형별로 보수방법을 달리하는 적극적인 해결방안의 모색이 필요하다. 따라서, 본 연구에서는 지하구조물의 누수보수에 있어서 방수 그라우트재의 공학적 특성을 파악하고 현장상황에 적합한 방수그라우팅 기법을 수립하여 누수유형별로 적용한 사례를 중심으로 적용성을 고찰하였다. 방수그라우팅 적용사례를 분석한 결과 지하구조물의 누수방지를 위하여 누수상황 및 누수유형에 따라 주입재의 배합비를 적절히 변화시켜 주입재와 현장상황에 적합한 방수그라우팅 기법을 병행 적용하는 것이 확실한 방수효과를 얻을 수 있으며, 주입목표구간에 대해 단계적으로 수회로 나누어 순차적인 그라우팅과 가능한 한 저압, 소량, 장시간에 걸쳐 주입하는 것이 방수그라우팅 효과를 증대시킬 수 있는 것으로 판단된다. 또한, 현장 적용결과로부터 기존 방수이론의 영향요소에 추가하여 물시멘트비, 주입재의 입경, 주입시간 및 주입량, 혼화재 사용여부, 주입차수 등에 대한 다양한 영향요소의 검토가 필요한 것으로 판단된다.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.25.2-38
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• 1995

the Effect of steel pipe reinforced multi-step grouting(SPRG) technique to inrove the ground far ahead of the excavation face was investigated by means of numerical analysis. It was found taht the nonlinear 3-D FEM program performed well to evaluate the usefulness of the SPRG technique in soft ground tunnelling, and about 20% of settlement control in this particular case possible. Therefore in urban subway tunnel construction, the New Austirial Tunnelling Method can be satisfactorily applied even in poor ground conditon with aid of the SPRG technique.

• Journal of the Korean Society of Safety
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• v.22 no.1 s.79
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• pp.54-60
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• 2007

This paper describes typical design and construction practice for in-situ ground reinforcement technique using improved steel pipe pressure grouting. A case history is presented to illustrate the benefit gained by application of the technique. This technique was applied to cut slopes developed in the construction of auxiliary spillway of 00 dam. Applicable conditions, method of survey, slope stability analysis and construction are given in this parer. As for the construction method, a procedure is given and the main points are the control of construction work. As a result of the pull-out test, it is shown that seel pipe nailing is particularly useful for stabilizing rock slope.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.796-804
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• 2008

Various design factors should be considered in order to apply the concrete slab track system on the soil/rock roadbed. One of the important factors is the settlement of roadbed. This settlement of concrete track should be supervised under the allowable settlement limit. If the settlement of roadbed under the concrete track exceed the allowable limit, the train serviceability will considerably come down and furthermore the fatal disaster may happen. Therefore, in this paper we introduced a digitalized grouting method as a settlement restoration method that can be suitably adopted to the concrete slab track. And we also evaluated the train service stability through the analysis of the track behavior according to the difference of the stiffness between the grouted part and the original roadbed.

• Tunnel and Underground Space
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• v.8 no.3
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• pp.209-225
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• 1998

Recently, Umbrella Arch Method(UAM), one of the auxiliary techniques for tunnelling, is used to reinforce the ground and improve stability of tunnel face. Because UAM combines the advantages of a modern forepoling system with the grouting injection method, this technique has been applied in subway, road and utility tunnel sites for the last few years in Korea. Also, several research results are reported on the examination of the roles of inserted pipes and grouted materials in UAM. But, because of its empirical design and construction methodology, more qualitative and systematic design sequences are needed. Therefore, above sequences using numerical analysis are proposed and, the effects of some design parameters were studied in this research. In order to acco,mplish these objects, first, the roles of pipe and grouting materials, steel-rib and the others in ground improving mechanism of UAM are clarified. Second, the effects of design parameters are investigated through parametric studies. Design parameters are as follows; 1) ground condition, 2) overburden, 3) geometrical formulation of pipes, 4) grouting region and 5) characteristics of pipes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.2
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• pp.43-63
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• 2023

With the concentration of the population in the city center and the saturation of the structures on the ground, the development of the underground structures becomes important and the construction of an adjoining tunnel that can reduce the overall problems is respected. In addition, it is necessary to apply the reinforcement construction method for the pillar part of the adjacent tunnel that can secure stability, economy and workability of the site. In this study, the tunnel pillar reinforcement method using prestress and grouting was reviewed. There are various reinforcement methods that can compensate for the problems of the side tunnel, but as the tunnel pillar construction method using prestress and grouting is judged to be excellent in field applicability, stability and economic feasibility, theoretical and numerical analysis of the actual behavior mechanism are conducted. Numerical analysis is divided into PC stranded wire + steel pipe reinforcement grouting + prestress (Case 1), pillar part tie bolt reinforcement (Case 2), pillar part non-reinforcement (Case 3) under the same ground conditions, and the maximum value of the celling displacement, internal displacement, and member force, the stability was confirmed. Through numerical analysis, it was confirmed that Case 1 which reinforced the PC stranded wire, was the best construction method and if it is verified and supplemented through field experiments later, it will be possible to derive superior results in terms of displacement control and member force than the currently applied reinforcement method was judged.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2102-2107
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• 2007

GSHP systems are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal and vertical type according to the installation method. Vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double u-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.29-39
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• 2010

By understanding the construction process of sea dikes and the current state of the thickness and speed of fluid in the bottom layer protection work of final closure gaps, a construction method applicable for the blocking of bottom layer work will be selected. The three construction methods selected will be tested in site through various methods, and the reinforcement of bottom layer protection and impervious effect will be verified. The verification results are as follows: 1) The overall riprap layer were 0.5~1.0m thicker than planned so that the grouting depth and grout input amount increased 2) The applied construction methods permeability of riprap layers were improved from $\alpha{\times}10^{-2}cm/s$ before the construction to $\alpha{\times}10^{-4}cm/s$ after construction. 3) The results of core extraction in order to grossly verify the hardening time and durability allowed the identification of grout injection effect. The amount of filling of the injection was difficult to judge because the slime in many areas made the reading of borehole photography difficult.