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Anchorage mechanism of inflatable steel pipe rockbolt depending on rock stiffness

팽창형 강관 록볼트의 암반 강성에 따른 정착 거동 특성

Kyeong-Cheol Kim1
,
Ho-Jong Kim2
,
Young-Hoon Jung3
,
Jong-Ho Shin4*
김 경철1
,
김 호종2
,
정 영훈3
,
신 종호4*
1Geotechnical Engineering & Tunnel Dept., Dasan Consultants
2Ph. D Student, Dept. of Civil Engr., Konkuk University
3Graduate Student, Dept. of Civil Engr., Konkuk University
4Professor, Dept. of Civil Engr., Konkuk University
1다산컨설턴트 지반터널부 사원
2건국대학교 공과대학 인프라시스템공학과 박사과정
3건국대학교 공과대학 인프라시스템공학과 석사과정
4건국대학교 공과대학 인프라시스템공학과 정교수
*교신저자. *Corresponding Author. 
31 March 2017. pp. 249-263
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Abstract

The expansion behavior of inflatable steel pipe rockbolt shows geometric nonlinearity due to its -shaped section. Previous studies on the anchoring behavior of inflatable steel pipe rockbolt were mainly performed using theoretical method. However, those studies oversimplified the actual behavior by assuming isotropic expansion of inflatable steel pipe rockbolt. In this study, the anchoring behavior of the inflatable steel pipe rockbolt were investigated by the numerical method considering the irregularity of pipe expansion and other influencing factors. The expansion of inflatable steel pipe rockbolt, the contact stress distribution and the change of the average contact stress and the contact area during installation were analyzed. The contact stresses were developed differently depending on the constitutive behavior of rocks. Small contact stresses occurred in steel pipes installed in elasto-plastic rock compared to steel pipes installed in elastic rock. Also, the anchoring behaviors of the inflatable steel pipe rockbolt were different according to the stiffness of the rock. The steel pipe was completely unfolded in the case of the stiffness smaller than 0.5 GPa, but it was not fully unfolded in the case of the stiffness larger than 0.5 GPa for the given analysis condition. When the steel pipe is completely unfolded, the contact stress increases as the rock stiffness increases. However, the contact stress decreases as the rock stiffness increases when the steel pipe is not fully expanded.

Keywords
팽창형 강관
록볼트
천공홀
접촉응력
인발력
정착 거동

팽창형 강관 록볼트의 설치 전 단면 형상은 형이어서, 팽창 중 거동은 기하학적 비선형 특성을 보인다. 기존 팽창형 강관 록볼트의 정착 거동에 관한 연구는 주로 이론적 방법이었다. 하지만 이론적 방법은 팽창형 강관 록볼트의 등방 팽창을 가정하므로, 실제 거동을 지나치게 단순화하였다. 본 연구에서는 강관 팽창 거동의 비선형성과 다양한 영향 특성을 고려한 수치해석을 이용하여, 팽창형 강관 록볼트의 정착 거동을 모사하였다. 본 해석을 통해 강관의 팽창 과정, 접촉응력 분포, 평균 접촉 응력 및 접촉 면적의 변화를 분석하였다. 암반의 탄소성 조건에 따라 강관의 접촉응력이 다르게 나타났는데, 탄성 조건의 암반에 설치된 강관에 비해 탄소성 조건의 암반에 설치된 강관에서 작은 접촉응력이 발생했다. 또한 암반의 강성에 따라 팽창형 강관 록볼트의 정착 거동이 달라졌다. 주어진 해석 조건에서 암반 강성이 0.5 GPa 이하 일 때 강관은 완전히 펴지지만, 암반 강성이 0.5 GPa보다 클 때 완전히 펴지지 않았다. 강관이 완전히 펴진 경우 암반 강성이 증가함에 따라 접촉응력의 크기가 증가했지만, 강관이 완전히 펴지지 않은 경우 암반 강성이 증가함에 따라 접촉응력의 크기가 감소했다.

키워드
Inflatable streel pipe rockbolt
Borehole
Contact stress
Pull-out resistance
Anchoring behavior
References
1
1.Freeman, T.J. (1978), “The behaviour of fully-bonded rock bolts in the Kielder experimental tunnel”, Tunnels & Tunnelling International, Vol. 10, No. 5, pp. 37-40.
2
2.Håkansson, U. and Li, C. (1997), “Swellex in weak and soft rock—design guidelines”, International symposium on rock support-applied solution for underground structures, Lillehammer, pp. 555-568.
3
3.Jeong, Y.Y., Choi, H.J., Kim, B.J., Yu, B.W., Kim, Y.I., Oh, S.J. (2007), “Design on the large section tunnel under shallow overburden”, Journal of Korean Tunnelling and Underground Space Association, Vol. 9, No. 2, pp. 171-182.
4
4.Kim, K.C. (2017), “A study on the behavior of inflatable pin-holed rockbolt”, Master Thesis, Konkok University, Republic of Korea, pp. 1-92.
5
5.Kim, Y.I., Yoon, Y.H., Cho, S.K., Yang, J.H., Lee, N.Y. (2002), “A Case study on the construction of a long tunnel in the youngdong railroad(Mt. Dongbeak-Dokye)”, Journal of Korean Tunnelling and Underground Space Association, Vol 4, No. 2, pp.155-165.
6
6.Li, C.C. (2016), “Analysis of inflatable rock bolts”, Rock Mechanics and Rock Engineering, Vol. 49, No. 1, pp. 273-289.
7
7.Li, C., Håkansson, U. (1999), “Performance of the Swellex bolt in hard and soft rocks”, Rock Support and Reinforcement Practice in Mining, 103.
8
8.Li, C., Stillborg, B. (1999), “Analytical models for rock bolts”, International Journal of Rock Mechanics and Mining Sciences, Vol. 36, No. 8, pp. 1013-1029.
9
9.Park, D.H., Kim, Y.K. (2007), “A study on analysis of tunnel behaviors considering the characteristics of in-situ stress distribution in rock mass”, Journal of Korean Tunnelling and Underground Space Association, Vol. 9, No. 3, pp. 275-286.
10
10.Son, S.G., You, J.O., You, J.H., Chung, J.M. (2011), “Field Evaluation of the Swelled Steel Tube Rockbolts”, 2011 Autumn conference & annual meeting of the Korea Society for railway, Jeju island, Republic of Korea, pp. 1149-1156.
11
11.Soni. A. (2000), “Analysis of Swellex bolt performance and a standardized rock volt pull test datasheet and database”, Master’s thesis, University of Toronto, Canada.
12
12.Wijk, G.and Skogberg, B. (1982), “The Swellex rock bolting system”, Proc. 14th Canadian Rock Mech. Sympo, 20.
Information
  • Publisher :Korean Tunneling and Underground Space Association
  • Publisher(Ko) :한국터널지하공간학회
  • Journal Title :Journal of Korean Tunnelling and Underground Space Association
  • Journal Title(Ko) :한국터널지하공간학회 논문집
  • Volume : 19
  • No :2
  • Pages :249-263
  • Received Date : 2017-03-14
  • Revised Date : 2017-03-24
  • Accepted Date : 2017-03-27
  • DOI :https://doi.org/10.9711/KTAJ.2017.19.2.249
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