Combined Effect ofWheel and Thermal Load Conditions on Stress Distribution in Flexible Pavement

Abstract

The aim of this research is to study the behavior of flexible pavement under wheel and thermal loading conditions using the finite element program ANSYS V (5.4). The stress states distribution within the asphalt concrete pavement that influence the direction of crack propagation have been investigated. The obtained results from ANSYS finite element program show that a maximum stress intensity factor value obtained at surface and then decrease with depth about (0.75 of asphalt layer thickness) due to reduction in temperature in asphalt layer, which indicates that crack will initiate at surface and extend throughout asphalt layer. The horizontal stress for both top and bottom layers increase with the variation of thermal coefficient expansion factor. High values of stresses at top surface of asphalt layer due to high contact stress were induced under wheel and thermal load conditions. As a result the highway pavement exhibited propagation of surface-initiated cracks. Field observation of cores extracted from asphalt concrete pavement confirmed the obtained results. ‫ﺍﻟﻤﺭﻥ‬ ‫ﺍﻟﺘﺒﻠﻴﻁ‬ ‫ﻋﻠﻰ‬ ‫ﺍﻟﻌﺠﻠﺔ‬ ‫ﻭﺤﻤل‬ ‫ﺍﻟﺤﺭﺍﺭﻱ‬ ‫ﺍﻟﺤﻤل‬ ‫ﺘﺄﺜﻴﺭ‬ ‫ﺍﻟﺨﻼﺼﺔ‬ ‫ﺤﻤل‬ ‫ﻅﺭﻭﻑ‬ ‫ﺘﺎﺜﻴﺭ‬ ‫ﺘﺤﺕ‬ ‫ﺍﻟﻤﺭﻥ‬ ‫ﺍﻟﺘﺒﻠﻴﻁ‬ ‫ﺘﺼﺭﻑ‬ ‫ﻟﺩﺭﺍﺴﺔ‬ ‫ﻫﻭ‬ ‫ﺍﻟﺒﺤﺙ‬ ‫ﻫﺫﺍ‬ ‫ﻤﻥ‬ ‫ﺍﻟﻬﺩﻑ‬ ‫ﺍﻥ‬ ‫ﺒﺭﻨﺎﻤﺞ‬ ‫ﺒﺎﺴﺘﺨﺩﺍﻡ‬ ‫ﺍﻟﺤﺭﺍﺭﻱ‬ ‫ﻭﺍﻟﺤﻤل‬ ‫ﺍﻟﻌﺠﻠﺔ‬ ANSYS V(5.4). ‫ﺘﻭﺯﻴﻊ‬ ‫ﻁﺒﻴﻌﺔ‬ ‫ﻋﻥ‬ ‫ﺍﻟﺘﺤﺭﻱ‬ ‫ﺘﻡ‬ ‫ﺍﻟﻜﻭﻨﻜﺭﻴﺘﻲ‬ ‫ﺍﻻﺴﻔﻠﺘﻲ‬ ‫ﺍﻟﺘﺒﻠﻴﻁ‬ ‫ﻓﻲ‬ ‫ﺍﻻﺠﻬﺎﺩﺍﺕ‬ ‫ﻴﻭﺜﺭ‬ ‫ﺒﺩﻭﺭﻩ‬ ‫ﺍﻟﺫﻱ‬ ‫ﺍﻟﺸﻘﻭﻕ‬ ‫ﺍﻨﺘﺸﺎﺭ‬ ‫ﻋﻠﻰ‬. ‫ﺍﻟﻨﺘﺎﺌﺞ‬ ‫ﺍﻥ‬ ‫ﺍﻟﻤﺤﺩﺩﺓ‬ ‫ﺍﻟﻌﻨﺎﺼﺭ‬ ‫ﺒﺭﻨﺎﻤﺞ‬ ‫ﻤﻥ‬ ‫ﺍﻟﻤﺴﺘﺤﺼﻠﺔ‬ ANSYS ‫ﺍﻻﺠﻬﺎﺩ‬ ‫ﺸﺩﺓ‬ ‫ﻟﻤﻌﺎﻤل‬ ‫ﻗﻴﻤﺔ‬ ‫ﺍﻋﻠﻰ‬ ‫ﺍﻥ‬ ‫ﺍﻅﻬﺭﺕ‬ ‫ﺒﺤﻭﺍﻟﻲ‬ ‫ﺍﻟﻌﻤﻕ‬ ‫ﻤﻊ‬ ‫ﺘﻘل‬ ‫ﻭﺜﻡ‬ ‫ﺍﻟﺴﻁﺢ‬ ‫ﻋﻠﻰ‬ ‫ﺘﻜﻭﻥ‬) 0.75 ‫ﺍﻻﺴﻔﻠﺕ‬ ‫ﻁﺒﻘﺔ‬ ‫ﺴﻤﻙ‬ ‫ﻤﻥ‬ (‫ﻨﻘﺼﺎﻥ‬ ‫ﻨﺘﻴﺠﺔ‬ ‫ﺍﻻﺴﻔﻠﺕ‬ ‫ﺒﻁﺒﻘﺔ‬ ‫ﺍﻟﺤﺭﺍﺭﺓ‬ ‫ﺩﺭﺠﺎﺕ‬. ‫ﺍﻟﺸ‬ ‫ﺍﻥ‬ ‫ﻴﻭﻀﺢ‬ ‫ﺒﺩﻭﺭﻩ‬ ‫ﻭﻫﺫﺍ‬ ‫ﻤﻊ‬ ‫ﻭﺘﻤﺘﺩ‬ ‫ﺍﻟﺴﻁﺢ‬ ‫ﻋﻠﻰ‬ ‫ﺘﺘﻭﻟﺩ‬ ‫ﻘﻭﻕ‬ ‫ﺍﻟﻁﺒﻘﺔ‬ ‫ﻋﻤﻊ‬. ‫ﻤﻌﺎﻤل‬ ‫ﺍﺨﺘﻼﻑ‬ ‫ﻤﻊ‬ ‫ﺘﺯﺩﺍﺩ‬ ‫ﻭﺍﻟﺤﺎﻓﺔ‬ ‫ﺍﻟﺴﻁﺢ‬ ‫ﻤﻥ‬ ‫ﻟﻜل‬ ‫ﺍﻻﻓﻘﻴﺔ‬ ‫ﺍﻻﺠﻬﺎﺩﺍﺕ‬ ‫ﺍﻥ‬ ‫ﻭﻜﺫﻟﻙ‬ ‫ﺍﻟﺤﺭﺍﺭﻱ‬ ‫ﺍﻟﺘﻤﺩﺩ‬. ‫ﻟﻼﺠﻬﺎﺩﺍﺕ‬ ‫ﻗﻴﻡ‬ ‫ﺍﻋﻠﻰ‬ ‫ﺍﻟﻌﺎﻟﻴﺔ‬ ‫ﻟﻠﻘﻴﻡ‬ ‫ﻨﺘﻴﺠﺔ‬ ‫ﺍﻻﺴﻔﻠﺘﻴﺔ‬ ‫ﺍﻟﻁﺒﻘﺔ‬ ‫ﺴﻁﺢ‬ ‫ﻋﻠﻰ‬ ‫ﺘﻜﻭﻥ‬ ‫ﻭﺍﻟﺤﻤ‬ ‫ﺍﻟﻌﺠﻠﺔ‬ ‫ﺤﻤل‬ ‫ﻁﺒﻴﻌﺔ‬ ‫ﺘﺎﺜﻴﺭ‬ ‫ﺘﺤﺕ‬ ‫ﺘﺘﻭﻟﺩ‬ ‫ﺍﻟﺘﻲ‬ ‫ﺍﻟﺘﻤﺎﺱ‬ ‫ﻻﺠﻬﺎﺩﺍﺕ‬ ‫ﺍﻟﺤﺭﺍﺭﻱ‬ ‫ل‬. ‫ﻋﻠﻰ‬ ‫ﻭﺍﻋﺘﻤﺎﺩﺍ‬ ‫ﺍﻟﺴﺭﻴﻌﺔ‬ ‫ﻟﻠﻁﺭﻕ‬ ‫ﺍﻟﻤﺭﻥ‬ ‫ﺍﻟﺘﻠﺒﻴﻁ‬ ‫ﺴﻁﺢ‬ ‫ﻤﻥ‬ ‫ﻭﺘﻨﺘﺸﺭ‬ ‫ﺘﻨﺸﺎ‬ ‫ﺍﻟﺸﻘﻭﻕ‬ ‫ﻓﺎﻥ‬ ‫ﺍﻟﻨﺘﺎﺌﺞ‬. ‫ﺍﻟﺤﻘﻠﻴﺔ‬ ‫ﺍﻟﻤﺸﺎﻫﺩﺓ‬ ‫ﺍﻟﻤﺴﺘﺤﺼﻠﺔ‬ ‫ﺍﻟﻨﺘﺎﺌﺞ‬ ‫ﻤﻊ‬ ‫ﺘﺘﻁﺎﺒﻕ‬ ‫ﺍﻟﻜﻭﻨﻜﺭﻴﺘﻲ‬ ‫ﺍﻟﻤﺭﻥ‬ ‫ﻟﻠﺘﻠﺒﻴﻁ‬ ‫ﻤﻘﺎﻁﻊ‬ ‫ﻤﻥ‬ ‫ﻤﺎﺨﻭﺫﺓ‬ ‫ﻟﻨﻤﺎﺫﺝ‬. PDF created with pdfFactory Pro trial version www.pdffactory.com