Selection of Genetic Algorithm Parameters for Backcalculation of Pavement Moduli

Abstract

In the context of pavement evaluation, backcalculation is the process of estimation of elastic properties of pavement layers using measured structural responses. A number of backcalculation programs are available for estimating effective pavement layer moduli from surface deflections. Different optimization techniques have been used in the development of these backcalculation models. Genetic algorithm (GA) has been used successfully in the recent past for backcalculation of pavement layer moduli. Selection of appropriate GA parameters is important for the efficient performance of the GA-based algorithm. However, there are no general guidelines available at present for the selection of GA parameters. This paper presents a study conducted for the selection of optimal GA parameters to be adopted for backcalculation of pavement layer moduli. The parameters have been selected on the basis of the level of accuracy desired and the corresponding computational effort (CE). The performance of the GA-based program with the selected parameters was evaluated using some hypothetical and field problems.

Small-Strain Behavior of Cement-Stabilized Recycled Concrete Aggregate in Pavement Base Layers

“…The resilient moduli of pavement layers can be obtained through different methods. The backcalculation technique is commonly used to calculate the pavement layer moduli through measurement of small deformations induced by accelerated loading facilities, heavy vehicle simulator or Falling Weight Deflectometer tests (de-Beer, et al, 1989, Reddy, et al, 2004, Zha and Xiao, 2003. In these methods, post processing of the achieved data and regression analysis using multilayered elastic theory is performed on the material.…”

“…The advantage of this approach is to use advance soil models to simulate the behavior of pavement structure. Elastic behavior for pavement layers has been used in the back-calculation of pavement layer moduli (de-Beer, et al, 1989, Reddy, et al, 2004. Piratheepan and Gnanendran (2013) used finite difference program with the same approach to match the results of prediction with finite difference program with that of measured in experimental test through an iterative adjustment of input parameters to achieve the actual resilient moduli of the pavement layer.…”

“…Many researchers have used elastic theory or elastoplastic material with Mohr-Coulomb failure criterion for modelling plastic deformations behavior of pavement granular soils under cyclic loading (Ebrahimi, et al, 2012, Martin, et al, 2003, Piratheepan and Gnanendran, 2013, Reddy, et al, 2004, however the stress dependency of soil stiffness's cannot be modelled using elastic theory. The shear modulus reduction from small strain domain towards larger shear strains is commonly ignored in elastic constitutive models.…”

The simple method of dynamic visco-elastic analysis of road structure. on rheological foundation

“…This involves the axially symmetric problem in cylindrical coordinates. On this basis the so called 'backcalculating methods' of pavement modulus are still in use [4][5][6][7][8][9][10][11][12][13][14]. As an example of such work, and as an example of almost exact accuracy, the paper of S. Firlej should be recalled [15].…”

Backcalculation of Non-Linear Pavement Moduli Using Finite-Element Based Neuro-Genetic Hybrid Optimization

“…Similarly, the implemented selection schemes include: roulette wheel, normalized geometric select, and tournament [34]. References [17,18], and [35] discuss the selection of optimal GA parameters for the pavement moduli backcalculation problem. These studies provided some guidelines in optimizing the GA parameters and operators for the current study.…”