| 摘要 |
PURPOSE:To relieve negative frictional forces by providing a water absorptive softening visco-elastic layer integrally on the outer surface of a part to be driven into the ground, e.g., pile, sheet pile, etc. CONSTITUTION:A water absorptive softening visco-elastic layer 2 composed of a NCO-terminated urethane polymer A having urethane bonds connected with aliphatic groups and NCO groups connected with aromatic groups is provided on the outer surface of a part 1 to be driven into the ground, e.g., pile or sheet pile, etc. When the part 3 with the visco-elastic layer 2 is driven into the ground, the layer 2 absorbs water in the ground and is swelled and softened to become a visco-elastic layer to relieve negative frictional forces acting on the part to be driven. |
