Performance of Reinforced Subbase Materials by Geogrid as Abase Layer Under Weak Subgrade

Highway and Transportation Department, Mustansiriyah University, Baghdad, Iraq

^a qaisalmusawi@uomustansiriyah.edu.iq
^b ghassan_hanan@uomustansiriyah.edu.iq
^c* Corresponding author edma028@uomustansiriyah.edu.iq

Abstract

The current study examines how an unpaved road behaves when it is installed on top of a soft clay layer that's been strengthened at the subgrade/subbase interface with a single layer of geogrid type SS2 is used to reinforce a laboratory model, and cycling load is used to apply repeated loads to the model. Subbases with and without reinforcement over soft subgrade were built in a sizable test box. (1000 mm×1000 mm×1000 mm). The test results show that using a geogrid reinforcement layer enhances the number of cycles and stress distribution while decreasing displacement on the soft subgrade surface on reinforced models compared to similar unreinforced ones for the same rutting value (85 mm). The rate of increase in failure time is about (6.12, 3.7, and 1.7) for 150, 230, and 300 mm thickness, respectively. The rate of redaction in vertical stress is about (18, 12.5, and 7.1) % for 150 mm, 230 mm, and 300 mm thickness, respectively.