Resilient and accumulative deformation properties of lateritic soil considering interparticle cementation damage

Lateritic soil is rich in free iron oxide (FIO), which enhances interparticle cementation and significantly affects deformation characteristics; however, how interparticle cementation damage influences the dynamic behaviors of lateritic soil remains unknown. The dithionite-citrate-bicarbonate treatment method was used to remove FIO from lateritic soil. Dynamic triaxial tests and microstructure tests were conducted on lateritic soils with different FIO removal rates. The influences of interparticle cementation damage on the resilient strain, resilient modulus, and accumulative plastic strain of lateritic soil were quantitatively analysed. The chemical composition and microstructure of lateritic soil under different FIO removal rates were analysed through microscopic tests. The results indicate that as the FIO removal rate and dynamic deviator stress increase, the dynamic resilient modulus decreases and the resilient strain increases compared with those of the samples without FIO removal. The removal of FIO from the lateritic soil resulted in interparticle cementation damage, and the stress–strain state changed from plastic stability to incremental failure. The prediction models of the dynamic resilient modulus, resilient strain, and accumulative plastic strain were established considering the dynamic deviatoric stress and FIO removal rate. In this research, the effect of interparticle cementation damage on accumulative deformation evolution is quantified, and these results provide insight into the mechanism underlying stiffness softening in lateritic soil.