| 摘要 |
PURPOSE: To develop a novel shield excavation method whereby the flowability of excavated sediment or the prevention of seepage during excavation is improved in shield tunneling methods, esp., the mud shield method. CONSTITUTION: A shield excavation method is developed wherein a flowable excavated sediment is quickly made nonflowable by mixing it with a compsn. comprising a water-sol. high-molecular substance and a boron compd. or an aldehyde compd., an aq. soln. of the compsn., or a dispersion of the compsn. in water or an org. solvent and then further mixing with an acidic or alkaline substance. Thus, by adjusting the pH of the excavated sediment after being mixed with the water-sol. high-molecular substance contg. the boron compd. or the aldehyde compd., the sediment is agglomerated, dehydrated, and made nonflowable, causing the sediment filled in the rear part of a screw conveyor to act as a cutoff plug against the earth pressure of the natural ground and thus to decrease the disturbance of the natural ground surrounding a shield cutting face and the settlement of the ground surface. |
