Open AccessApplying a Mathematical Model to the Calculations of Layer Moduli: In Relation to the Falling Weight Deflectomer
Author(s) -
Azhar Abbas Majeed
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1362/1/012144
Subject(s) - moduli , stiffness , deflection (physics) , subgrade , modulus , elasticity (physics) , young's modulus , structural engineering , falling weight deflectometer , materials science , mechanics , mathematics , mathematical analysis , geotechnical engineering , geometry , geology , physics , composite material , engineering , classical mechanics , quantum mechanics
Back calculations of layer stiffness are preceded by initial analyses of the deflection bowl in conjunction with the measured or assumed thickness of the layers. This step is important in understanding the strains, stresses, and moduli in the individual layers. An accurate modelling of the stiffness of the subgrade is observed to be important because a failure to achieve accuracy implies that disproportionately large errors are likely to arise during the back-analysis. Notably, the latter is applicable in for the provision of the upper layer moduli (State Highway Administration, 2016). With the existence of packages that aid in bob-linear subgrade analysis, the use of a system such as the ELMOD package uses deflections for calculating “n” and C. the relationship holds: E = C (σz/a’)n where n and C refer to constants σz = vertical stress σ’ = reference stress E = modulus of elasticity