Vol. 14, No. 2, pp. 115-141(2018)
A SIMPLE ANALYTICAL METHOD FOR EVALUATION OF FLEXIBLE ROCKFALL
BARRIER PART 1: WORKING MECHANISM AND ANALYTICAL SOLUTION
Z.X. Yu1,2, Y.K. Qiao1, L. Zhao1, H. Xu1*, S.C. Zhao1,2 and Y.P. Liu3
1 School of Civil Engineering, Southwest Jiaotong University, Chengdu, China
2 National Engineering Laboratory for prevention and control of geological disasters in land transportation, Chengdu, China
3 Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University,
Hung Hom, Kowloon, Hong Kong, China
*(Corresponding author: E-mail:This email address is being protected from spambots. You need JavaScript enabled to view it.)
Received: 4 January 2017; Revised: 25 May 2017; Accepted: 5 June 2017
DOI:10.18057/IJASC.2018.14.2.1
 View Article |
Export Citation: Plain Text | RIS | Endnote |
ABSTRACT
The flexible rockfall barrier system exhibits large deflection and complex contact behaviors such that sophisticated finite element method and full-scale test are widely used to design this kind of structures, which causes inconvenient for most engineers. In this paper, a simple analytical method is proposed for fast evaluation of the performance of the flexible rockfall barrier system on the basis of system deflection characteristics observed in the full-scale impact tests and, the component deflection characteristics from component tests such as the puncturing deflection of steel wire-ring net, elongation of energy dissipating device, sliding movement of supporting rope and rotation of support structure. The equation for prediction of large deflection of flexible rockfall barrier system was established. The overall deflection is contributed by its components and therefore the analytical solutions for calculation of component deflections were derived based on the space geometry analysis and verified by component tests. The analytical solution for steel wire-ring nets were validated by 17 puncturing tests and the maximum difference was less than 7.4%. Using the discrete ring net model, an explicit dynamic method was employed to simulate the nonlinear behaviors of flexible rockfall barriers with different design energies, i.e. 2000 kJ, 3500 kJ and 5000 kJ. The deflection of each component and the overall deflections from analytical solutions were compared with the numerical simulations with the maximum difference less than 7.9%. Thus, the proposed analysis solution for evaluation of large deflection of flexible rockfall barrier system is valid and ready for engineering design. A companion paper is presented in part two separately with full-scale test for further verification of the proposed method.
KEYWORDS
flexible rockfall barrier, impact, buffer performance, large deflection, analytical solution, full-scale test
REFERENCES
[1] EOTA. Guideline for European technical approval of falling rock protection kits (ETAG 027), 2012, Brussels.
[2] Zhao Shichun, Yu Zhixiang, Zhao Lei, et al. “Damage mechanism of rockfall barriers under strong impact loading”, Journal of Engineering Mechanics, 2016, Vol. 33, No. 10, pp. 24-34.
[3] Zhao Shichun, Yu Zhixiang, Wei Tao, et al. “Test study of force mechanism and numerical calculation of safety netting system [J]”. Journal of China Civil Engineering Journal, 2013, Vol.46, No. 5, pp. 122-128.
[4] Gottardi G, Govoni L. “Full-scale Modelling of Falling Rock Protection Barriers”. Journal of Rock Mechanics & Rock Engineering, 2010, Vol. 43, No. 3, pp. 261-274.
[5] Peila D, Pelizza S, Sassudelli F. “Evaluation of Behaviour of Rockfall Restraining Nets by Full Scale Tests”. Journal of Rock Mechanics & Rock Engineering, 1998, Vol. 31, No. 1, pp. 1-24.
[6] Grassl H, Bartelt P A, Volkwein A, et al. “Experimental and numerical modeling of highly flexible rockfall protection barriers” Proceedings of 12th Panamerican Conference on Soil Mechanics and Geotechnical Engineering, Cambridge, Massachusetts, USA, 2003, Vol. 2589―2594.
[7] Qi Xin. “The Mechanics Performance of Passive Flexible Protection Structure”. Southwest Jiaotong University, 2014.
[8] Escallón J P, Wendeler C, Chatzi E, et al. “Parameter identification of rockfall protection barrier components through an inverse formulation”. Journal of Engineering Structures, 2014, Vol. 77, pp. 1-16.
[9] Kwan J S H,Chan S L, Cheuk J C Y, et al. “A case study on an open hillside landslide impacting on a flexible rockfall barrier at Jordan Valley”, Journal of Hong Kong. Landslides, 2014, Vol. 11, No. 6, pp. 1-14.
[10] Escallón J P, Boetticher V, Wendeler C, et al. “Mechanics of chain-link wire nets with loose connections”. Journal of Engineering Structures, 2015, Vol. 101, pp. 68-87.
[11] Morton E.C., Thompson A.G., Villaescusa E. “Testing and analysis of steel wire mesh for mining applications of rock surface support[J]”. Proceedings of 5thWorld Congress on Computational Mechanics, Vienna, Austria.
[12] Gentilini C, Gottardi G, Govoni L, et al. “Design of falling rock protection barriers using numerical models”. Journal of Engineering Structures, 2013, Vol.50, No. 3, pp. 96-106.
[13] Nicot F., Cambou B., and Mazzoleni G. “Design of Rockfall Restraining Nets from a Discrete Element Modeling”.Journal of Rock Mechanics and Rock Engineering. 2001, Vol. 34, No. 2, pp. 99-118.
[14] Bertrand D, Trad A, Limam A, et al. “Full-Scale Dynamic Analysis of an Innovative Rockfall Fence Under Impact Using the Discrete Element Method: from the Local Scale to the Structure Scale”. Journal of Rock Mechanics & Rock Engineering, 2012, Vol. 45, No. 5, pp. 885-900.
[15] Moon T, Oh J, Mun B. “Practical design of rockfall catchfence at urban area from a numerical analysis approach”. Journal of Engineering Geology, 2014, Vol. 172, No. 5, pp. 41-56.
[16] Gentilini C, Govoni L, Miranda S D, et al. “Three-dimensional numerical modelling of falling rock protection barriers”. Journal of Computers & Geotechnics, 2012, Vol. 44, No. 44, pp. 58-72.
[17] Volkwein A. “Numerical modelling of flexible rockfall protection systems”. Journal of American Society of Civil Engineers, 2013, Vol. 11, No. 179, pp. 1-11.
[18] De Miranda, S., Gentilini, C., Gottardi, G., Govoni, L., Mentani, A., Ubertini, F. “Virtual testing of existing semi-rigid rockfall protection barriers”. Journal of Engineering Structures, 2015, Vol. 85, pp. 83-94.
[19] Govoni, L., de Miranda, S., Gentilini, C., Gottardi, G., Ubertini, F. “Modelling of falling rock protection barriers” Journal of Physical Modelling in Geotechnics, 2011, Vol. 11, No. 4, pp. 126-137.
[20] De Miranda, S., Gentilini, C., Gottardi, G., Govoni, L., Ubertini, F.,“A simple model to simulate the full-scale behaviour of falling rock protection barriers Physical Modelling in Geotechnics”,Proceedings of the 7th International Conference on Physical Modelling in Geotechnics 2010, Vol. 2, pp. 1247-1252.
[21] Qiao Wentao, An Qi, Zhao Mingshan, et al., “Experimental study on the fundamental mechanical features of cable-supported ribbed beam composite slab structure”, Advanced Steel Construction, 2017, Vol. 13, No. 2, pp. 96-116.
[22] Guo Jiamin, Yuan Xingfei, Xiong Zhixin, et al., “Force finding of suspended-domes using back propagation (BP) algorithm”, Advanced Steel Construction, 2016, Vol. 12, No. 1, pp. 17-31.
[23] Luo Bin, Guo Zhengxing, Chen Xiangnan, et al., “Static equilibrium form-finding analysis of cable-strut system based on nonlinear dynamic finite element method”, Advanced Steel Construction, 2015, Vol. 11, No. 4, pp. 452-468.
[24] Escallón J P, Wendeler C.,“Numerical simulations of quasi-static and rockfall impact tests of ultra-high strength steel wire-ring nets using Abaqus/Explicit”, 2013 SIMULIA community conference, 2013.
[25] Castanon-Jano L, Blanco-Fernandez E., “Castro-Fresno D, et al Energy Dissipating Devices in Falling Rock Protection Barriers”, Journal of Rock Mechanics & Rock Engineering, 2017, Vol 50, pp. 1-17.
[26] J.J. del Coz Díaz,P.J. García Nieto , D. Castro-Fresno , J. Rodríguez Hernández .,“Nonlinear explicit analysis and study of the behaviour of a new ring-type brake energy dissipator by FEM and experimental comparison”, Journal of Applied Mathematics and Computation 2010, Vol. 216, No. 5, pp. 1571–1582.
[27] Dhakal S, Bhandary N P, Yatabe R, et al.,“ Numerical and analytical investigation towards performance enhancement of a newly developed rockfall protective cable-net structure”, Journal of Natural Hazards & Earth System Sciences, 2012, Vol. 12, No. 4, pp. 1135-1149.
[28] D. Castro-Fresno, J.J. del Coz Diaz, L.A. López, P.J. García Nieto., “Evaluation of the resistant capacity of cable nets using the finite element method and experimental validation”, Engineering Geology, 2008, Vol. 100, No. 1-2, pp. 1–10.
[29] Grassl H, Volkwein A, Anderheggen E, et al., “Steel-net Rockfall Protection – Experimental And Numerical Simulation”, Seventh international conference on structures under shock and impact. Montreal, Canada, pp 143–153.
[30] Muhunthan, B., H. Radhakrishnan, “Finite Element Analysis of Hybrid Barrier for Rock Fall Slope Protection”, Final Report, Department of Civil and Environmental Engineering, Washington State University, 2007.
[31] GB/T 20118-2006, Steel wire ropes for general purpose, Standardization Administration of the People's Republic of China, Beijing, 2006.
[32] Livermore software technology corporation (LSTC), “LS-DYNA keyword user’s manual volume I”, 2007.