Asphalt mow strips are typically used as vegetation barriers around guardrail posts in the design of roadside safety structures. Asphalt mow strips have historically been modeled as a rigid layer in simulations; this assumption results in significant ground level restraint on the guardrail post. However, experiments have shown that asphalt rupture should be considered in the analysis of the response of guardrail posts embedded in mow strips. The present study investigates the effect of asphalt material properties and mow strip geometry on guardrail post performance using finite element simulations. Numerical simulations are performed and correlated with results from static experiments and material testing. The test simulations and experimental results are used to evaluate the response of guardrail posts with various mow strip designs to predict the level of restraint from the asphalt layer. The model is then used to investigate the effects of asphalt material properties and mow strip geometry on the overall performance of the system. The results demonstrate that including asphalt rupture in numerical simulations is essential in accurately predicting the behavior of guardrail posts installed in asphalt mow strips. In addition, mow strip geometry along with asphalt material properties significantly affect the guardrail post response.
KeywordsGuardrail PostsAsphalt Mow StripsLS-DYNAFinite Element SimulationsRoadway Safety
Reid, J. (2004) LS-DYNA Simulation Influence on Roadside Hardware. Transportation Research Record: Journal of Transportation Research Board, 1890, 34-41. https://doi.org/10.3141/1890-04
Atahan, A.O. (2010) Vehicle Crash Test Simulation of Roadside Hardware Using LS-DYNA: A Literature Review. International Journal of Heavy Vehicle Systems, 17, 52-75. https://doi.org/10.1504/IJHVS.2010.029623
Mohan, P., Dhafer, M., Meczkowski, L. and Bedewi, N. (2005) Finite Element Modeling and Validation of a 3-Strand Cable Guardrail System. International Journal of Crashworthiness, 10, 267-273. https://doi.org/10.1533/ijcr.2005.0345
Sicking, D., Reid, J. and Rohde, J. (2002) Development of the Midwest Guardrail System. Transportation Research Record: Journal of the Transportation Research Board, 1797, 44-52. https://doi.org/10.3141/1797-06
Plaxico, C., Ray, M. and Hiranmayee, K. (2000) Impact Performance of the G4(1W) and G4(2W) Guardrail Systems: Comparison under NCHRP Report 350 Test 3-11 Conditions. Transportation Research Record: Journal of the Transportation Research Board, 1720, 7-18. https://doi.org/10.3141/1720-02
Bligh, R.P., Abu-Odeh, A.Y. and Menges, W.L. (2011) MASH Test 3-10 on 31-Inch W-Beam Guardrail with Standard Offset Blocks. Report FHWA/TX-11/9-1002-4, College Station.
Dewey, J.F., Jeyapalan, J.K., Hirsch, T.J. and Ross, H.E. (1983) A Study of the Soil-Structure Interaction Behavior of Highway Guardrail Posts. Research Report 3431, College Station.
Ferdous, M.R., Abu-Odeh, A., Bligh, R.P., Jones, H.L. and Sheikh, N.M. (2011) Performance Limit Analysis for Common Roadside and Median Barriers Using LS-DYNA. International Journal of Crashworthiness, 16, 691-706. https://doi.org/10.1080/13588265.2011.623023
Plaxico, C.A., Patzner, G.S. and Ray, M.H. (2007) Finite Element Modeling of Guardrail Timber Posts and the Post-Soil Interaction. Transportation Research Record: Journal of Transportation Research Board, 1647, 139-146. https://doi.org/10.3141/1647-17
Wu, W. and Thomson, R. (2007) A Study of the Interaction between a Guardrail Post and Soil during Quasi-Static and Dynamic Loading. International Journal of Impact Engineering, 34, 883-898. https://doi.org/10.1016/j.ijimpeng.2006.04.004
Bligh, R.P., Seckinger, N.R., Abu-Odeh, A.Y., Roschke, P.N., Menges, W.L. and Haug, R.R. (2004) Dynamic Response of Guardrail Systems Encased in Pavement Mow Strips. College Station.
AASHTO (2011) Roadside Design Guide. 4th Edition, AASHTO, Washington DC.
Dusty, A.R., Bligh, R.P. and Menges, W.L. (2009) Alternative Design of Guardrail Posts in Asphalt or Concrete Mowing Pads. College Station.
Scott, D.W., Lee, S.H., Bakhtiary, E., Arson, C.F. and White, D.W. (2015) Static Response of Steel Guardrail Posts Driven through Asphalt Vegetation Barriers. Transportation Research Board, Washington DC.
Scott, D.W., White, D.W., Stewart, L.K., Arson, C.F., Bakhtiary, E. and Lee, S.H. (2015) Evaluating the Performance of Guardrail Posts Installed by Driving through Asphalt Layers. Final Report for Georgia Department of Transportation Research Project 13-21, Atlanta.
Sicking, D.L., Mak, K.K., Rohde, J.R. and Reid, J.D. (2009) Manual for Assessing Safety Hardware. AASHTO, Washington DC.
Tabiei, A. and Wu, J. (2000) Roadmap for Crashworthiness Finite Element Simulation of Roadside Safety Structures. Finite Element in Analysis and Design, 34, 145-157. https://doi.org/10.1016/S0168-874X(99)00035-9
Kulhawy, F.H., Trautmann, C.H., Beech, J.F. and O’Rourke, T.D. (1983) Transmission Line Structure Foundations for Uplift-Compression Loading. Report EPRI EL-6800.
ASTM (2001) Standard Test Methods for Tension Testing of Metallic Materials. ASTM E8/E8M, West Conshohocken.
Budhu, M. (2010) Soil Mechanics and Foundations. 3rd Edition, John Wiley & Sons Inc., Hoboken.
USACE (1982) Bearing Capacity of Soils: Engineering Manual. United States Army Corps of Engineers, Washington DC.
Bowles, J.E. (2001) Foundation Analysis and Design. 5th Edition, McGraw-Hill, New York.
Christensen, R.F. and Bonaquist, D.W. (2004) Evaluation of Indirect Tensile Test (IDT) Procedures for Low-Temperature Performance of Hot Mix Asphalt. No. 530, Transportation Research Board, Washington DC.
Pellinen, T.K., Song, J. and Xiao, S. (2004) Characterization of Hot Mix Asphalt with Varying Air Voids Content Using Triaxial Shear Strength Test. 8th Conference on Asphalt Pavements for Southern Africa, Sun City, 12-16 September 2004.
Lewis, B.A. (2004) Manual for LS-DYNA Soil Material Model 147. No. FHWA-HRT-04-095, FHWA, Washington DC.
Reid, Y.D., Coon, J.D., Lewis, B.A., Sutherland, B.A. and Murray, S.H. (2004) Evaluation of LS-DYNA Soil Material Model 147. No. FHWA-HRT-04-094, FHWA, Washington DC.
Davis, R.O. and Selvadurai, A.P. (2005) Plasticity and Geomechanics. Cambridge University Press, Cambridge.
USCS (1985) Classification of Soils for Engineering Purposes: Annual Book of ASTM Standards. American Society for Testing and Materials, West Conshohocken.
AASHTO (2012) Specification for Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses. AASHTO M147, AASHTO.
AASHTO (2007) Sieve Analysis of Fine and Coarse Aggregates. AASHTO T27, AASHTO.
ASTM (2000) Standard Method of Test for Direct Shear Test of Soils under Consolidated Drained Conditions. ASTM D3080, ASTM, West Conshohocken.
Lekarp, D.A. and Richardson, I.R. (1996) Influences on Permanent Deformation Behavior of Unbound Granular Materials. Transportation Research Record, 1547, 68-75. https://doi.org/10.3141/1547-10