Experimental Study on Preparation of Circulating Tunneling Slurry for Slurry Shield Tunneling

In order to realize shield waste slurry recycling, waste slurry was applied to the preparation of tunneling slurry. The performance difference between waste slurry and bentonite was compared in an indoor test based on Nanjing Yangtze River Xinjizhou river crossing water supply corridor project, and the feasibility of preparing tunneling slurry from waste slurry was analyzed. The law of the influence of waste slurry viscous particle content and ratio on the performance of digging slurry was studied. A fitting formula for the performance indexes of the dredging slurry was established, and the ratio optimization analysis of the dredging slurry prepared from waste slurry was carried out based on the fitting formula. The research results effectively proved the feasibility of preparing tunneling slurry from waste slurry, and through ratio optimization, the reference ratio for the preparation of digging slurry from waste slurry in the relying project was determined: solid to water ratio 0.22, bentonite clay ratio 0.28, and CMC dosing 0.32%. The optimized ratio of the tunneling slurry can meet the performance requirements, which can provide a reference for determining the ratio of the tunneling slurry prepared by recycling the waste slurry in the project.