Abstract:The resource utilization of engineering residual soil and industrial solid waste is one of the key measures for advancing the development of "zero-waste cities". Using modified diatomite, phosphogypsum, and carbide slag as eco-friendly and low-carbon solid waste-based stabilizers, stabilization and resource utilization tests were conducted on excavated residual soil from Suzhou foundation pit projects. With a stabilizer mix ratio of modified diatomite: carbide slag∶ phosphogypsum=0.39∶ 0.23∶0.38 (8% dosage), the effects of initial moisture content and compaction pressure on the compaction degree and unconfined compressive strength (UCS) of stabilized soil were investigated. Taking compaction pressure and duration as variables controlling compaction degree and subsequent strength, the optimal parameters of compaction technology for strength enhancement were refined. The results showed that under test conditions in this study, when the initial moisture content reached the liquid limit, the optimal compaction parameters were 0.92 MPa for 20 minutes, achieving 2.39 MPa UCS on day 28. When the initial moisture content fell below 20%, the hydration of the stabilizers among soil particles was insufficient. Increasing the compaction pressure significantly promoted the reaction of stabilizers among soil particles, resulting in a relatively significant influence on strength enhancement. When the initial water content exceeded the liquid limit, a water film was formed between soil particles and the stabilizers that isolated their contact, reducing cementation capacity and strength.
