Project Description

Tunnel projects of Tokyo Metro Line 13 are one of the biggest construction projects in Japan. A new metropolitan subway is extended to Shibuya Station,one of the biggest stations in Tokyo. The tunnel is constructed by dig and cast method, where waterproofing layer of 27’000 m2 in total is established prior to concrete walls.

Project Requirements

The material must fulfill not only the waterproofing performance requirement of JIS A 6021, but also achieve high adhesion strength with concrete walls. Because the shorter construction period is a key to build a tunnel in the middle of the city, fast curing PU method is appreciated.

Sika Solutions

After cleaning the rock surface, a flex sheet is fastened to the rock surface. Thereafter, Sikalastic® CV Spray has been sprayed. To achieve the required adhesion, Doubletex® RG is applied with a roller. After building a frame work, the ready mix concrete is casted and a waterproofing layer attached to the tunnel surface is established.

Sika Products

In addition the following Sika products were used in the project

  • Sikalastic® CV Spray
  • Doubletex® RG

Project Participants

Owner: Tokyo Metropolitan Subway
General Contractor: No.1 JV Tokyu, Totetsu Corp, No.2 JV Kajima, Aisawa, Mitsubishi, No.3 Tokyu Construction Corp.
Applicator: Toshin Kaken Ltd.
Sika company: Dyflex, Japan