Correlation between grease consumption of slurry shield and geological conditions: case of one cross river section of a subway in Wuhan City

Grease is one of the main consuming materials in mud shield tunneling, and its consumption has strong correlation with geological conditions. In this paper, taking the cross river section of a subway in Wuhan City as an example, the medium cemented conglomerate,complex of weak cemented conglomerate and weathering conglomerate, and silty sand soil are represented by S1,S2,S3 respectively, and the correlation between geological conditions and grease consumption (W) is studied by using the least square method. And the mathematical relationship between grease consumption and different geological materials volume is obtained by regression analysis. The results show that the more complex the geological conditions, the more harder the strata are, the more grease is consumed in the mud-water shield tunneling process, and in the soft and hard combination formation,W=2.704VS2+0.594VS3; in the complex composite formation, W=1.552VS1+1.707VS2+1.460VS3. The calculation results are of practical significance for grease management in subway tunnel construction.