The movement of superheavy loads (SHLs) has become more common over the years, since it is a vital necessity for many important industries, such as chemical, oil, electrical, and defense. SHL hauling units are much larger in size and weight compared to standard trucks. SHL vehicles' gross vehicle weights may be in excess of a few million pounds, so they often require specialized trailers and components with nonstandard spacing between tires and axles. Accommodating SHL movements requires the determination of whether the pavement is structurally adequate and involves the analysis of the likelihood of instantaneous or rapid load-induced shear failure. As part of the Federal Highway Administration project DTFH61-13-C-00014, Analysis Procedures for Evaluating Superheavy Load Movement on Flexible Pavements, an analysis package (alpha version), Superheavy Load Vehicle Movement on Flexible Pavement (SuperPACK), was developed to evaluate specific cases of SHL-vehicle movements. SuperPACK is developed in MATLAB as a stand-alone software package.
SuperPACK comprises three components: pre-analysis modules (A modules), analysis modules (B modules), and an analysis engine (3D-Move ENHANCED). The A modules, which are required to proceed to the B modules, require information on vehicle axle configurations, material properties, subgrade shear strength parameters, and representative material properties for the analysis and reference vehicles. The B modules conduct bearing capacity, service limit, slope stability, buried utility, and cost allocation analyses. All the A and B modules require pavement responses, excepting the module on vehicle axle configurations. 3D-Move ENHANCED was developed to provide the modules with responses based upon the request. The analysis engine is based on the original formulation of 3D-Move. However, several enhancements to the original formulation were incorporated in the SHL-vehicle movement analysis. For instance, runtime was improved using inverse Fourier transform, and parallel processing techniques were implemented so that different axle groups of an SHL vehicle could be analyzed in a reasonable amount of time.
The SuperPACK main window contains general information about the project, as well as basic information needed for a 3D-Move ENHANCED analysis (e.g., layer thicknesses, material types). The A and B modules can be accessed through the SuperPACK main window. A function and GUI were specifically developed for each module. Each GUI collects specific information needed to execute its corresponding module. Additionally, 3D-Move ENHANCED provides the modules with the necessary pavement responses when requested. The A and B modules share information through the SuperPACK main window.