• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.137-144
• /
• 2005

Recently a pressurized grouting soil nail is demanded due to problems beyond of economical and engineering purpose. In this study, a newly modified soil nailing technology named as the PGSN (Pressurized Grouting Soil Nailing) system is respected to reduced displacements of nails and increase of global slope stability. And effects of various factors related to the design of the PGSN system, such as the length of the soil nail, injected pressure and W/C ratio of cement grout in the pressurized grouting soil nail are examined throughout a series of the displacement-controlled field pull-out tests. Displacement-controlled field pull-out tests are performed in the present study and the volume of grouting are also evaluated based on the measurements. In addition, both short-term and long-term characteristics of pull-out deformations of the newly proposed PGSN system are analyzed and compared with those of the general soil nailing system by carrying out the stress-controlled field pull-out tests. From the pull-out characteristics of pressurized grouting soil nails, it is found that the effect of the length of the soil nail, injected pressure and W/C ratio of cement grout are important parameters.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 봄 학술발표회 논문집
• /
• pp.137-144
• /
• 1999

Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study removable soil nails are developed and field pull-out tests are carried out 16 times in order to analysis pull-out characteristics of the removable soil nail. For the spacing and the installed position of fixed socket, the length of the soil nail, and W/C ratio of cement grout in the removable soil nail, pull-out characteristics of pull-out tests are analyzed. From the pull-out characteristics of removable soil nails, it is found that the spacing of fixed socket and W/C ratio of cement grout are important design parameters.

• 한국지반환경공학회 논문집
• /
• 제9권2호
• /
• pp.61-65
• /
• 2008

본 연구에서는 PGSN(Pressurized Grouting Soil Nailing) 시스템이라는 가압 그라우팅 쏘일네일링 공법을 고안하였으며, 본 공법의 보강제의 길이변화 및 보강재의 변화 등의 설계인자에 따른 거동변화를 파악해 보기 위해 변위제어방식의 현장인발시험을 수행하였다. 본 연구에서 수행한 9차례의 현장인발시험에서 그라우트 주입비의 변화를 살펴 보기위해 계측을 수행하였으며, 단기거동특성을 평가하기 위해 일반 쏘일네일링 시스템과 비교해 보았다. 가압 그라우트 쏘일네일링 공법의 인발거동 특성을 통해, 중요한 설계인자인 주입압 및 그라우트 주입비 등의 영향을 살펴보았다. 시험 결과 가압효과에 따른 인발변형 특성은 중력식 그라우팅 쏘일네일에 비해 가압 그라우팅 쏘일네일의 경우 유발되는 변위량이 30~36% 정도 감소하였고, 보강재 변화에 따른 인발 특성을 살펴보면 이형철근에 비해 강관의 경우 유발되는 변위량이 31~32% 정도 감소하는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.651-658
• /
• 2004

In this study, we introduced the spiral pipe nailing system (refer as SPN system) with self drilling method, can apply to ground which is hard to keep shape of bore hole, and performed limit equilibrium analysis with simplilied trial wedge method while length ratio and bond ratio were altered to evaluate slope stability considered of tensile strength and bending stiffness. A newly soil nailing system named as the SPN system is respected to reduce displacement of nail and increase global slope stability. And effects of various factors related to the design of the SPN system, such as the type of drilling method and the bit, are examined throughout a series of the displacement-controlled field pull-out tests. 6 displacement-controlled field pull-out tests are performed in the present study and the volume of grouting arc also evaluated based on the measurements. In addition, short-term characteristics of pull-out deformations of the newly proposed SPN system are analyzed and compared with those of the general soil nailing system by carrying out the displacement-controlled field pull-out tests.

• 한국지반공학회논문집
• /
• 제24권8호
• /
• pp.43-52
• /
• 2008

본 연구에서는 단철근 네일과 다철근 네일의 인장강도를 조사하기 위해 단철근과 다철근 네일의 극한인발시험과 크리프시험을 수행하였다. 철근과 시멘트 그라우트의 부착력과 인장하중에 의해 유발된 마찰력, 하중전이 특성을 조사하였다. 단철근과 다철근 네일의 현장인발시험과 유한차분해석 프로그램의 하나인 $FLAC^{2D}$를 이용하여 얻은 결과를 분석하고 비교하였다. 다철근 네일의 현장인발시험결과 단철근 네일에 비해 인발파괴하중이 크고 하중전이가 큼을 알 수 있다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.342-347
• /
• 2004

Excavation nearby the existing structures is being performed vigorously to get the greatest use of land along with fast economic growth in the downtown area. The application of soil nailing system gradually increases because of an advantage of soil nailing system adjacently constructed in the existing structures. In this study, friction resistance by pull-out is considered as main resistance except resistance formed by flexural rigidity of nail observing that resistance of flexural rigidity is about $0{\sim}15\;%$ of whole safety factor according to degree of flexural rigidity in general soil nail wall and application of geosynthetic fiber soil nailing system is evaluated through laboratory tensile strength test and field pull-out test.

• 한국지반공학회논문집
• /
• 제26권2호
• /
• pp.15-22
• /
• 2010

본 연구에서는 현장 인발시험을 통하여 강관다단 가압식 쏘일네일링의 거동특성을 분석하였다. 이를 위하여 총 10공의 쏘일네일을 풍화토에 시공하여 인발시험을 실시하였다. 인발시험 결과에 의하면 쏘일네일의 극한인발력은 가압식 쏘일네일이 중력식 쏘일네일에 비하여 42~142% 증가하는 것으로 나타났다. 네일과 주변지반 경계면에서의 전단강도는 중력식 네일이 71kPa, 가압식 네일이 95~166kPa를 보이는 것으로 확인되었다. 가압식 쏘일네일의 경우 중력식 쏘일네일에 비하여 그라우트의 직경이 약 12~27% 증가하는 것으로 나타났다. 또한, 공팽창이론에 의한 가압 시 지반변위 산정값과 현장 인발시험을 통하여 측정한 값을 비교하였으며, 그 결과는 대체적으로 비슷한 경향을 보였다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2003년도 봄 학술발표회 논문집
• /
• pp.521-528
• /
• 2003

In this study, a newly modified soil nailing technology called as the NDB(New Down and Board) soil nailing system is introduced. To improve the trafficability, workability, and economical efficiency, SMC(Sheet Molding Compound) board is adopted instead of using the concrete block facing. The SMC board has a distinct advantage of showing a fine view by directly coating with any kind of environmental photos. Composite material properties of the SMC board and cement grout are distinguished features of the NDB soil nailing system. In the present study, both laboratory tests(bending and punching failure tests) and field pull-out tests are carried out to analyze the behavior characteristics of the NDB soil nailing system, including the stress and strain distribution.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 가을 학술발표회 논문집
• /
• pp.481-488
• /
• 1999

Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study controlled displacement and controlled force field pull-out tests are carried out 7 times in order to evaluate short-term and long-term pull-out characteristics of the removable soil nail. For evaluating application of removable soil nailing system, bending tests of removable soil nails and tensile tests of fixed sockets are carried out. In the removable soil nailing system, the predicted horizontal displacements from FLAC-2D are also compared with the field measurements occurred in stepwise excavation. And approach for the stability analysis of removable soil nailing system after removed is proposed.

• 한국지반환경공학회 논문집
• /
• 제4권3호
• /
• pp.27-40
• /
• 2003

본 연구에서는 프리텐션을 적용한 쏘일네일링 공법을 제시하고, 프리텐션 쏘일네일링 시스템에 대한 변위제어방식 현장인발시험을 총 9회 실시하여 프리텐션 쏘일네일링 구조체의 관련 설계변수인 쉬스관 길이 및 고정콘 유 무 등에 대한 영향에 대해 분석하였으며, 아울러 프리텐션 하중의 평가도 다루어 졌다. 또한 응력제어방식 현장인발시험을 총 3회 실시하여, 일반 쏘일네일 및 프리텐션 쏘일네일의 장 단기적인 인발-변형 특성 등을 비교 분석하였다. 계속해서, 프리텐션 쏘일네일링 시스템의 안정성 평가를 위해, 예상파괴면 및 최소안전율을 결정하기 위해 사면안정해석 등에 주로 적용되고 있는 전단강도감소기법을 이용한 수치해석적 접근방법의 제시 및 분석 등이 이루어졌다.