Tunnel Boring Machine Brushes and Tunnel Segments

A view of the tail seal brushes on a tunnel boring machine. In this situation, the tail seal brushes needed replaced and there was water flowing through seams in the tunnel segments. To control the heavy flow of water, polyurethane grout was injected around the leaks. The grout used was SealGuard II, which is manufactured by SealGuard, Inc. SealGuard II is a dual component, fast reacting material that can be easily applied with a dual component caulking gun. The grouting was performed by Sub-Technical, Inc.