摘要 |
PURPOSE:To prevent the increase of cutter torque application due to the adhesion of cohesive soil and restoration of strength of earth in a method of earth pressure shield construction. CONSTITUTION:Moisture in excavated soil taken into a chamber 2 by the propulsion of a shielding machine 1 is given electrons theta having negative charges through an electron generator 5 and a turbine pump 6 from a water tank 4. The whole negative potential in the chamber is increased by agitation, cations in the pore water of cohesive soil particles in the chamber 2 are neutralized, and cohesion among soil particles is reduced. |