AASHTOWare Pavement ME Design is the next generation of AASHTOWare® pavement design software, which builds upon the mechanistic-empirical pavement design guide, and. Pavement Design/Analysis Software Important Note: The following programs can be downloaded and be used by students in CE475 or CE575 for educational purposes only.

And ABSTRACT Backcalculating layer moduli, using the deflections measured by the FWD (Falling Weight Deflectometer) device, is the basis for structurally evaluating pavements when considering maintenance and rehabilitation options. Many algorithms have been developed to perform the backcalculation.

Most of them are based on simplified assumptions such as the elastic behavior of the pavement and static load. These algorithms use the peak values of loads and deflections recorded by the FWD sensors. The dynamic analysis, to the contrary, accounts for the dynamic nature of the load and factors such as material inertia and damping. These algorithms use as inputs both load and deflection time histories measured by the FWD. In this research, three software programs, MODULUS 6.0, ELMOD 5.0 and EVERCALC 5.0, were used to do the elasto-static back-analysis and the DBSID program was employed for the dynamic backcalculation. The FWD data gathered from different test sites, including the Zanjan-Tabriz, Eivanekey-Garmsar and Garmsar-Semnan freeways and also Rafsanjan airport have been used in this evaluation. The results have been compared, the performance of each program has been evaluated and the best software for the sites under study is suggested.

Services How to cite this article: M. Yavari and T. Scullion, 2009.

Comparison of Static and Dynamic Backcalculation of Flexible Pavement Layers Moduli, Using Four Software Programs. Asian Journal of Applied Sciences, 2: 197-210.

DOI: URL: INTRODUCTION The modulus of elasticity is the major parameter in the remaining life analysis and in the design of new pavements and overlays. Untalkative Bunny Theme Song Mp3 Download. This critical value is computed through the backcalculation method, which uses the FWD raw data (). Most of the common backcalculation algorithms, which use the peak values of load and deflection at each sensor during every drop, assume that the FWD load is applied statically.

The pavement system is modeled as a layered elastic system with linear or nonlinear (stress-dependent) materials. A forward analysis subroutine is used to calculate the theoretical deflections under the known load. Attempts are made to converge these calculated deflections to the measured ones.

In other words, the moduli are predicted by minimizing the error between the measured and calculated deflections in every step of iteration. But in reality, the FWD applies an impulse load to the pavement that generates body waves and surface waves, which travel at finite velocities and are recorded at different times by the geophones ().