Filter cake is critical to maintaining the stability of the excavation face of an underwater shield tunnel in a high-permeability stratum. In a high-permeability formation. generating an effective filter cake on the excavation face is difficult with a pure bentonite slurry. which penetrates the ground and may not achieve the required suspension pressure. https://www.ealisboa.com/deal-find-Orca-Vape-x-Suicide-Mods-Stubby-MTL-Conversion-Kit-huge-savings/