Experimental Study on Composite Slurry Ratio for Synchronous Grouting of Shield Tunneling in Rich Water Powder Fine Sand Layer
In order to improve the efficiency and quality of synchronous grouting for shield tunneling in water rich fine sand formations,accurately control the upward displacement of pipe segments,and conduct proportioning tests in order to obtain a slurry with good adaptability to water rich formations.Based on the conventional inert slurry,the dosage range of two additives,hydroxyethyl cellulose(HEC)and polycarboxylic acid(PC),is determined by single factor test.Then,the range of test results of water binder ratio,water glass,hydroxyethyl cellulose and polycarboxylic acid in four factors and three levels is analyzed by orthogonal test,and the composite slurry mix ratio with good fluidity,controllable gel time and high stone rate is obtained.The results show that the optimal ratio of composite slurry for water rich silty fine sand formation is 0.8(A2),30％(B2),0.1％(C1)and 0.2％(D2)of PC,PC,HEC.This ratio optimizes the water resistance dispersion and economy of the slurry while ensuring the fluidity(consistency 10～12 cm),gel time(90～150 s),stone rate(97.53％)and compressive strength(2.63 MPa).Adopting the recommended slurry ratio for synchronous grouting,the upward displacement of the pipe segment can be controlled within 20 mm,meeting the regulatory requirements.
rich water powder fine sand layershied tunnelgrout mixorthogonal experimentupward displacement of segment
万方数据
维普
