Numerical modeling of roughness-induced dynamic tire loading on flexible pavements

Said, Izak

Permalink

https://hdl.handle.net/2142/115654 Copy

Description

Title

Numerical modeling of roughness-induced dynamic tire loading on flexible pavements

Author(s)

Said, Izak

Issue Date

2022-01-28

Director of Research (if dissertation) or Advisor (if thesis)

Al-Qadi, Imad L

Doctoral Committee Chair(s)

Al-Qadi, Imad L

Committee Member(s)

• Duarte, Armando
• Roesler, Jeffery
• Chehab, Ghassan
• Harvey, John
• Ozer, Hasan

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Finite Element Analysis, Dynamic Loading, Pavement Damage, Critical Responses

Abstract

The increase in pavement surface roughness leads to dynamic loading amplification, which results in higher stress states in the pavement structure and causes damage. The primary objective of this doctoral dissertation is to quantify the impact of roughness-induced dynamic loading on pavement service life. Additional pavement critical responses induced by increased road roughness were measured, considering dynamic three-dimensional (3-D) and non-uniform contact stresses. The road roughness was converted to a dynamic loading profile using a mechanical full truck-trailer dynamic model. Then, the dynamic loading profiles were transformed into dynamic 3-D contact stresses, which were applied to typical thick and thin pavement structure models. The dynamic loading was found to be amplified due mainly to road profile and speed. The effect was more pronounced in the thick pavement compared to the thin one. On the other hand, tire pressure had a negligible impact on dynamic loading distribution. The resultant rutting and top-down cracking due to roughness-induced dynamic loading were investigated, including the confinement level effect. A constitutive model was developed for confinement-dependent asphalt concrete (AC) linear viscoelastic behavior. The model was then incorporated into finite-element pavement models. Multiple loading levels were selected to consider the effect of pavement roughness on tire loading amplification. Results show that the effect of confinement depends on the relative position of the moving load, and therefore, it is time dependent. Moreover, the increase in loading due to road roughness causes higher confinement levels and deeper zones of influence. The roughness-induced dynamic loading of various tire configurations, steering, dual assembly tires (DTA), and wide-base tires (WBT), and its effect on pavement responses was performed using two analysis methods, conventional critical pavement responses and strain energy domain analysis. Steering, WBT, and DTA have different mass and stiffness properties, resulting in distinct dynamic loading despite their same pavement roughness. This task assesses the impact of tire configuration on pavement dynamic loading and responses. The results show that the road roughness' highest effect is on the steering tire's load and responses. A consistent amplification was found for DTA and WBT. The strain-energy method could capture the loading history's influence better than the single maximum-point responses. Finally, roughness-induced dynamic loading was incorporated within the mechanistic-empirical pavement design methodology. A five-step framework was developed: input parameters' determination, development of critical pavement response database, using AASHTOWare's transfer function to predict pavement damage, predict International Roughness Index (IRI) and incorporate roughness induced dynamic loading once the IRI exceeds 95 in/mi. A simple analytical dynamic-loading model was fitted based on mechanistic truck-trailer results. The dynamic loading was found to have the most significant impact on fatigue, followed by rutting. The effect on thick and strong pavement sections is relatively less pronounced. The outcome of this effort was validated using measured and predicted IRI from the Specific Pavement Study (SPS-5) sections, which is part of the Long-Term Pavement Performance program.

Graduation Semester

2022-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Izak Said

Owning Collections