Abstract:

Soda residue (SR) is a kind of solid wastes produced in the process of soda with the method of ammonia-soda. As a ground backfill soil, SR can effectively solve the problems of land occupation and pollution after appropriate reinforcement and treatment. However, because of the poor stability of physical and mechanical properties, the material strength of SR would be weaken obviously under the action of cyclic loading such as mobile machinery loading, which will reduce the bearing capacity of SR foundation. In this study, dynamic triaxial compression tests were performed on the undisturbed SR derived from Tianjin Port. Then, the cyclic cumulative pore pressure variation and undrained shear strength variation of SR under different stress conditions were discussed. Based on Yasuhara equivalent overconsolidation model, a cyclic strength weakening model of SR considering the influence of anisotropic consolidated ratio and dynamic stress ratio was established by using strength weakening coefficient β to quantify the weakening effect of cyclic loading on the strength of material. On this basis, a strength evolution model of SR considering the coupling effect of anisotropic consolidation process and cyclic loading process was established by using strength enhancement coefficient a to quantify the effect of anisotropic consolidation process on the strength of material. The accuracy of this model was validated by comparing the experimental measurements with the model calculation results.

Key words: soda residue, solid wastes, cyclic loading, anisotropic consolidated, cyclic cumulative pore pressure, undrained shear strength