Study on Creep Constitutive Model of Remolded Malan Loess Based on Memory-Dependent Derivatives

Creep deformation of remodeled loess has important implications in loess fill engineering. To deeply study the creep characteristics of remodeled loess, triaxial graded cyclic loading and unloading creep tests were carried out on remolded Malan loess under different confining pressure conditions. The test results show that the creep behavior of remolded loess under different stress levels can be classified into three categories: viscoelastic decelerated creep under low stress; viscoelastic–plastic decelerated creep under medium stress; and full-course creep containing decelerated, steady, and accelerated creep under high stress. The creep process can cause damage to remolded loess, and reducing loads and increasing support can reduce the risk from creep. On this basis, a four-component remolded loess creep constitutive model was proposed in the framework of memory-dependent derivative theory and damage mechanics. The applicability of the newly proposed theoretical model was verified by fitting it to the creep test data and comparing it with the Nishihara model. The research results contribute to a better understanding of the creep properties of remolded loess and lay the foundation for solving the settlement problem in loess filling engineering.