Karafan Journal

Karafan Journal

Evaluation of Changing Effects of Density and Thickness of Polyurethane as a Protective Coating on Underground Tunnels under Surface Blast

Document Type : Original Article

Authors
Mohsen Fazlavi 1
AmirAbbas Asadian 2
1 Assistant Professor, Departement of Civil Engineering, Faculty of Enghelab-e Eslami, Tehran Branch, Technical and Vocational University (TVU), Tehran, Iran.
2 MSc, Department of Civil Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran.
10.48301/kssa.2021.131053
Abstract
The use of polyurethane as a sacrificial coating is an important factor in reducing risks and improving the safety of structures against explosions caused by war and terrorist attacks. The parameters of polyurethane can have a positive effect on reducing damage to tunnels under the impact of surface explosions. In this paper, the effect of density and thickness of the protective cover of polyurethane (as an energy absorber) in reducing the damage caused by surface explosions on underground tunnels was studied by computer simulation with AUTODYN software. Six different foam modules with thicknesses between 60 and 150 cm, and five different types of foams with densities between 90 and 250 kg / m 3 and their ability to reduce the maximum pressure caused by an explosion were compared. The results of this study illustrated that by increasing the thickness of the protective cover of polyurethane, a significant decrease occurred in the amount of pressure and vertical displacement in the tunnel crown. Moreover, the findings on the effect of polyurethane density indicated that at a density of 140 kg/m3, the optimum reduction in pressure in the tunnel crown occurred.
Keywords
Porous Material
Surface Blast
Polyurethane
Tunnel. Protective Coating
[1] Endo, K., Kitagawa, K., & Yasuhara, M. (2009, June 22-25 ). Diffusion Effect of Blast Pressure in Porous Complex Media. 39th AIAA Fluid Dynamics Conference, San antonio, Texas. https://arc.aiaa.org/doi/abs/10.2514/6.2009-3569
[2] Lee, M., Wang, GM., Sung, PH., Chang, WL., Lee, YL., & Lin, K. (1986). The attenuation of shock waves in PU foam and its application. In Shock Waves in Condensed Matter. Springer. https://doi.org/10.1007/978-1-4613-2207-8_101
[3] Hall, W. J., Newmark, Nathan Mortimore., & , & Hendron, A. J. (1974). Classification, Engineering Properties and Field Exploration of Soils, Intact Rock and in Situ Rock Masses. U.S. Atomic Energy Commission. https://books.google.com/books?i d=ai9IAQAAMAAJ
[4] Lee, W. Y. (2006). Numerical Modeling of Blast-Induced Liquefaction [Doctor of Philosophy, Brigham Young]. Provo, Utah, United States. https://scholarsarchive.b yu.edu/etd?utm_source=scholarsarchive.byu.edu%2Fetd%2F524&utm_medium=PDF&utm_campaign=PDFCoverPages
[5] Cheeseman, B. A., Wolf, S., Yen, C. F., & Skaggs, R. (2006). Blast simulation of explosives buried in saturated sand. Fragblast, 10(1-2), 1-8. https://doi.org/10.108 0/13855140500432045
[6] Yang, Y., Xie, X., & Wang, R. (2010). Numerical simulation of dynamic response of operating metro tunnel induced by ground explosion. Journal of Rock Mechanics and Geotechnical Engineering, 2(4), 373-384. https://doi.org/10.3724/SP.J.1235.2 010.00373
[7] De, A. (2012). Numerical simulation of surface explosions over dry, cohesionless soil. Computers and Geotechnics, 43, 72-79. https://doi.org/10.1016/j.compgeo.2012.0 2.007
[8] De, A., Morgante, A. N., & Zimmie, T. F. (2016). Numerical and physical modeling of geofoam barriers as protection against effects of surface blast on underground tunnels. Geotextiles and Geomembranes, 44(1), 1-12. https://doi.org/10.1016/j.geo texmem.2015.06.008
[9] Lezgi, M., Izadifard, Ramazan Ali., & Lashgari, Mohammad Reza. (2017). Evaluation Of Nonlinear Response Of Reinforced Concrete Frames Designed According To Earthquake Codes And Subjected To Blast Loading. Scientific Journal of Advanced Defense Science and Technology 8(3 ), 201-212. https://www.sid.ir/en/j ournal/ViewPaper.aspx?id=572971
[10] Izadifard, R. A., & Foroutan, M. (2010). Blastwave parameters assessment at different altitude using numerical simulation. Turkish Journal of Engineering and Environmental Sciences, 34(1), 25-42. https://doi.org/10.3906/muh-0911-39
[11] Andami, M. (2016). The Performance of high density polyurethane foams in blast damage mitigation [MSc Thesis, Razi University]. Kermanshah, Iran.
[12] Boey, C. W. (2009). Investigation of shock wave attenuation in porous materials [Masters, Naval Postgraduate School]. Monterey, California. https://hdl.handle.net /10945/4386
[13] Herrmann, W. (1969). Constitutive Equation for the Dynamic Compaction of Ductile Porous Materials. Journal of Applied Physics, 40(6). https://doi.org/10.1063/1.165 8021
[14] Johnson, G. R., & Cook, W. H. (1985). Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures. Engineering Fracture Mechanics, 21(1), 31-48. https://doi.org/10.1016/0013-7944(85)90052-9
[15] Hallquist, J. O. (2007). LS-DYNA keyword user’s manual. L. S. T. Corporation. https://pdfhall.com/ls-dyna-version-970-keyword-users-manual-ftp-directory-listin g_5b2e78c0097c4731608b458b.html
[16] Wang, Z., Lu, Y., Hao, H., & Chong, K. (2005). A full coupled numerical analysis approach for buried structures subjected to subsurface blast. Computers & Structures, 83(4-5), 339-356. https://doi.org/10.1016/j.compstruc.2004.08.014
[17]  Code, I. N. B. (2008). Passive defense (part 21).
[18] Henrych, J., & Major, R. (1979). The dynamics of explosion and its use. Elsevier Amsterdam. https://books.google.com/books/about/The_Dynamics_of_Explosion_ and_Its_Use.html?id=yeRdswEACAAJ
[19] Andami, M. H., & Toopchi Nezhad, H. (2018). The Performance Of Rigid Polyurethane Foams In Damage Mitigation Of Structures Due To The Impact Of A Supersonic Projectile. Mechanical Engineering Sharif (Sharif: Mechanical Engineering), 34-3(2 ), 133-140. https://www.sid.ir/en/Journal/ViewPaper.aspx?I D=822650
Karafan Journal
Volume 18, Issue 1 - Serial Number 52
Technical and Engineering
Spring 2021
Pages 121-137

  • Receive Date 04 January 2021
  • Revise Date 17 February 2021
  • Accept Date 24 February 2021