Mechanical Characteristics of Soda Residue Soil Incorporating Different Admixture: Reuse of Soda Residue

Soda residue (SR), a waste by-product of sodium carbonate production, occupies land resources and pollutes the environment seriously. To promote the resource reusing of waste SR, this paper studies the feasibility of utilizing SR for the preparation of soda residue soil (SRS) through laboratory and field tests. The SR and fly ash (FA) were mixed with six different proportions (SR:FA is 1:0, 10:1, 8:1, 6:1, 3:1, 1:1) to prepare SRS, and the optimum water content, maximum dry density, shear strength, and unconfined compression strength of the SRS were measured. The representative SRS (SR:FA is 10:1) was selected to investigate the compression performance and collapsibility. The preparation and filling method of SRS in the field was proposed, and the effects of gravel, sand, and lime on the mechanical properties of SRS were studied through field tests. The results show that the addition of FA contributed to the strength development of SR, and the addition of lime, sand and rubble have a significant effect on the subgrade bearing capacity of SRS. The subgrade bearing capacity and deformation modulus of SRS in field tests is more than 210 kPa and 34.48 MPa, respectively. The results provide experimental basis and reference for the preparation of SRS, the scientific application of SRS in geotechnical engineering to promote sustainable development.