soil nailing technique using gfrp
- 3. SOIL NAILING • Soil nailing is a construction technique that can be used as a remedial measure to treat unstable natural soil slopes or as a construction technique that allows the safe over steepening of new or existing soil slopes. • The procedure involves the insertion of relatively slender solid or hollow reinforcing elements into the slope. • Solid bars are usually installed into pre-drilled holes and then grouted into place, whereas hollow bars may be drilled and grouted simultaneously and by pumping grout down the hollow bar as drilling progresses in a soil nailed retaining wall.
- 4. • The properties and material behavior of three components-the native soil,the reinforcement (nails) and the facing element-and their mutual interaction significantly affect the performance of the structure Soil Nailing On Hill Slope(Piyush Sharma,2015)
- 5. FAVOURABLE GROUND CONDITION FOR SOIL NAILING • Soil nails can be used for wide range of soil types and conditions . Experience have shown that certain favourable ground condition make soil nailing cost effective over other techniques. • Soil nailing has proven economically attractive and technically feasible when: • Soil in which the excavation is constructed should able to stand unsupported in a 1m – 2m (3 to 6 ft) high vertical or nearly vertical cut for one to two days.
- 6. • All soil nails within a cross section are located above the groundwater table • If the soil nails are below the groundwater table, the groundwater does not adversely affect the face of the excavation, the bond strength of the interface between the grout and the surrounding ground, or the long-term integrity of the soil nails (e.g., the chemical characteristics of the ground do not promote corrosion). • It is advantageous that ground condition allow drill holes to be advanced without use of drill casing and for the drill holes to be unsupported for few hours until nail bars are installed and drill hole is grouted.
- 7. Components Of Soil Nail Wall(Ravindra Budania, Dr. R.P Arora,2016) COMPONENTS OF A SOIL NAIL WALL
- 8. • Nail bars
- 9. • Nail head • Grout Steel Plate and Steel Nut Heads(Ravindra Budania, Dr. R.P Arora,2016)
- 10. • Centralizers
- 13. GFRP • Fiberglass is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet or woven into a fabric. • Other common names for fiberglass are glass-reinforced plastic (GRP) and glass- fiber reinforced plastic (GFRP) or GFK . • Because glass fiber itself is sometimes referred to as "fiberglass", the composite is also called "fiberglass reinforced plastic". This article will adopt the convention that "fiberglass" refers to the complete glass fiber reinforced composite material, rather than only to the glass fiber within it.
- 14. WHY GLASS FIBER REINFORCED POLYMER? • The current method of steel soil nail construction is both labour intensive as well as expensive. • As construced soil nails are always buried in the ground, they cannot be inspected or maintained routinely. Therefore, corrosion protection is of paramount importance to the longevity of steel soil nails installed in slopes. • .Many engineers are considering use of new soil nail materials.an innovative soil nail is constructed by light weight high strength glass fiber reinforced plastic pipe. • The main advantages of GFRP over conventional method is that it is corrosion resistant ,light weight,high strength to weight ratio etc
- 16. • The total area of Hong Kong is approximately 1,103km2 , accommodating a population of 6.8 million. The terrain of Hong Kong is hilly. To accommodate the population and economic development, many slopes are formed for land development to cope with the rapid development. • Currently, high yield steel bars are used as soil nails to stabilize slopes in Hong Kong and many other countries.In Hong Kong, higher factors of safety are required as many buildings are constructed adjacent to slopes. • But in steel soil nail bars corrosion protection is of paramount importance to the durability in slopes.
- 17. The features that would be desired for soil nails in Hong Kong include the following: • Light weight and high strength • Application of pressure to control the grouting zone, quality of grouting, and bond strength • Address corrosion problems • Acceptable cost • Ease of construction—handling, joining, and cutting.
- 18. • The authors have carried out research works on the use of GFRP bars as soil nails for a project at Sanatarium Hospital in Hong Kong. • For the present system, GFRP pipes of 37mm internal diameter and 5mm are utilized. The pipes are fabricated by pultrusion process. • The Pultrusion Process involves the following: Glass fiber is drawn from spools through a resin bath where the reinforcement is impregnated with the resin .
- 19. Spools of Glass Fiber(Alfred et al,2009) The impregnated fibers are woven into the designed pattern and pulled by the pultrusion machine at a constant rate through a steel die heated to a precisely controlled temperature to cure resin.
- 20. Drawing of Glass Fiber and Impregnation With Liquid Thermosetting resin(Alfred et al,2009) Weaving of the Impregnated Glass Fiber(Alfred et al,2009)
- 21. • The composite is thermoset and molded to the pipe shape Pulling of Impregnated Glass fiber through Shaping Die(Alfred et al,2009) Thermoset and Molding of GFRP pipe to exact shape(Alfred et al,2009)
- 22. Structural sections of GFRP pipe manufactured in this process possess the following advantages: • Strength—the strength is high and can be controlled easily by the use of different fiber or resin. • Lightweight—the unit weight is about 18–20% of steel. • Corrosion resistance—can be controlled easily for various purposes and is much better than structural steel. • Electrical resistance—nonmagnetic and insulator to electric. • Manufacturing process—small parts can be joined together to form large parts easily by the pultrusion process.
- 23. CONCLUSION • GFRP possesses a very high tensile strength which can be controlled easily by the use of different resin. • The shear strength of the material can be controlled by the addition of FRP layers wrapped at 45° to the longitudinal direction and the actual lamination of the FRP as produced from the pultrusion process • Through the active research it was established that the use of light weight high strength GFRP can be utilized as an alternative to the classical steel bar soil nail. • While most researchers and engineers are working on the use of FRP bars as soil nail, the present study has demonstrated that FRP pipe can be a competitive solution for steep slope with limited working space.
- 24. REFERENCE • Albert T. Yeung, Y. M. Cheng ; L. G. Tham, Alfred S. K. Au, Sunny T. C. and Yongki Choi(2007). “Field Evaluation of a Glass-Fiber Soil Reinforcement System”.Journal of Performance of Constructed Facilities,Vol.21,No.1 • Alfred S. K. Au, W. B. Wei , J. Chen, Y. M. Cheng, Yong-ki Choi, Albert T. Yeung, L. G. Tham, (2009).” New Soil Nail Material—Pilot Study of Grouted GFRP Pipe Nails in Korea and Hong Kong” Journal of Materials in Civil Engineering, Volume:21,Issue Number: 3 • Hong-Hu Zhu; Jian-Hua Yin, Albert T. Yeung, and Wei jin(2011). “Field Pullout Testing and Performance Evaluation of GFRP Soil Nails”. Journal Of Geotechnical And Geoenvironmental Engineering,
- 25. • Huafu Pei, Jianhua Yin ,Honghu Zhu, Chengyu Hong(2013).“Performance Monitoring of a Glass Fiber-Reinforced Polymer Bar Soil Nail during Laboratory Pullout Test Using FBG Sensing Technology”. • Marek Kulczykowski, Jarosław Przewłócki, Bogusława Konarzewska(2017). “ Application of Soil Nailing Technique for Protection and Preservation Historical Buildings”, IOP Conf. Ser.: Mater. Sci. Eng. • Piyush Sharma(2015). “Theoretical Analysis Of Soil Nailing: Design, Performance And Future Aspects” International Journal of Engineering Research and General Science, Volume 3, Issue 6 • Ravindra Budania, Dr. R.P Arora(2016).” Soil Nailing for Slope Stabilization: An Overview” International Journal of Engineering Science and Computing, Volume 6 Issue No. 12 • Soheil ghareh(2015). “Parametric Assessment Of Soil Nailing Retaining Structures In Cohesive And Cohesionless Soils”. Measurement,Volume:73
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