Date of Award

2009-01-01

Degree Name

Master of Science

Department

Civil Engineering

Advisor(s)

Cesar Carrasco

Second Advisor

Soheil Nazarian

Abstract

A significant amount of research and development has been conducted for decades to provide a tool for the design and analysis of jointed slabs on different types of foundations. ILLI-SLAB, JSLAB, EverFE and ISLAB are the most used finite element modeling (FEM) codes that have gone through several iterations of improvement. JSLAB has been maintained by the Federal Highway Administration (FHWA) and is distributed free of charge and there is significant interest in further improving the capabilities of that software package.

Researchers at the University of Texas at El Paso have been charged to implement several modifications in the latest version of JSLAB called JSLAB2004. A thorough review of JSLAB2004 source code that was developed in the 1970's revealed that it would be beneficial to recode the software completely to take advantage of the modern programming and FEM tools available today. As such, a new code was developed in MATLAB that significantly enhances the efficiency and capabilities of JSLAB2004. The new software will be referred to as NYSlab hereafter. Some of the improvements include using isoparametric elements that capture shear deformations and allows flexibility to use un-structured meshes; and introducing gap elements to model the contact between several slabs and slab and foundation (instead of the ad-hoc algorithm currently used in JSLAB). There is also now no limitation on the number of slabs and foundation layers for defining a pavement structure. The simulation of temperature gradient is also improved for the modeling of curling of the slabs where the gradient can now be non-linear and exist in any number of slab layers.

In addition to discussing the improvements to JSLAB2004 in this thesis, a comparison between the improved code and the other codes previously mentioned is also presented. Several studies were also conducted to determine the convergence characteristics of the FEM formulation. Finally, several parametric studies were conducted to verify the appropriate behavior of the code for different geometric configurations, foundation models and parameters, and temperature gradient profiles.

These studies indicate that the new code results compare well with the other codes and have good convergence characteristics. The parametric studies also demonstrate a well behaving code for various pavement-section configurations.

Language

en

Provenance

Received from ProQuest

File Size

77 pages

File Format

application/pdf

Rights Holder

Maryam Limouee

Download

Share

COinS