Dynamic Behavior of Asphalt Stabilized and Grid Reinforced Subgrade Soil

saad sarsam; Ahmad AL Sandok

doi:10.3759/ttea.v5i2.828

Abstract

The impact of repeated loading (punching shear) on Asphalt stabilized and grid reinforced subgrade soil have been investigated in this study. Specimens of 152mm diameter and 116 mm in height have been prepared, cured, and then tested using the pneumatic repeated load system PRLS. The deformation-load repetitions data were recorded for each case. Data were fed to the finite element software for the modeling process. An assessment was conducted to search for the best realistic simulation, therefore the finite element models were developed using ABAQUS 6.13 software package. For pure and asphalt stabilized soil, the axisymmetric model was implemented. On the other hand, the reinforcement layers were simulated with shell element, the analysis results were then compared with those of experimental tests. Perfectly plastic model has been adopted to simulate all of the reinforcement layers, i.e. geogrid, geosynthetic and geotextile. It was concluded that the finite element simulation has given a good agreement with that of experimental tests. It was concluded that Geotextile is capable to hold the stresses at the top layer of the soil and restrict its impact on the specimen. The Geosynthetic exhibit lower ability of stress absorption while the Geogrid impact on stress absorption was minimal. The numerical analysis showed a good agreement with experimental work in case of asphalt stabilized soil. The reduction in total displacement due to stabilization was (88 and 89) % after (1000 and 1800) load repetitions respectively. Stabilization or reinforcing the subgrade soil have improved its load sustaining ability by controlling the total displacement of the specimens significantly.