Stress-strain ratio on stabilization work in the saturated zone causes rapid road failure

Abstract Road construction frequently encounters difficulties with soil with low bearing capacity, such as soil subsidence, which results in the deformation or waves of the surface road. The investigation was conducted at the Paya Tumpi quarry and quarry in Krueng Raya-Laweung, which are the providers of soil material used in road construction. These two quarries, due to their extensive clay soil criteria, are unsuitable for use as road subgrade material. Hence, to utilize this soil, it is necessary to stabilize it by incorporating volcanic ash. This will be accomplished by evaluating the shear strength of mixed soil, the optimum water content for compaction, and the stress-strain ratio’s behaviour as a result of the stabilization effect. To determine the cohesion and shear angles at a defined shear stress and the response of each test object to strain and stress, a series of experiments were carried out. The research findings indicated that the cohesion and shear angles of the soil samples were enhanced by the addition of volcanic ash in comparison to natural soil. The cohesion (c) of sample-1, sample-2, and sample-3 increased from 0.034-0.223 kg/cm 2 , 0.093-0.118 kg/cm 2 , and 0.008–0.037 kg/cm 2 , respectively. Similarly, the shear angles (ϕ) increase from 32.30o to 40.30o, 27.20o to 30.10o, and 27.90o to 36.20o, respectively. The stress-strain ratio is intermediate between local failure and punching.