Large-Scale Post-Grouting Works in the Stockholm Bypass-Video

Video Transcription

Video Summary

The Stockholm Bypass is a 21-kilometre road tunnel project where unusually extensive post-grouting was required: in some sections, about 70% of the tunnels needed it. Strict groundwater-inflow limits, challenging geology, and large tunnel dimensions drove repeated grouting, monitoring, and changes to the original approach. Post-grouting substantially reduced leakage, but disrupted construction and added more than €200 million in costs in one project section. Roof and wall grouting is quicker and less disruptive; bottom grouting can reduce inflow further but requires stopping other work. The presentation highlighted ongoing measurement and adaptive grouting as key to achieving the required tunnel tightness.

Keywords

Stockholm Bypass

road tunnel

post-grouting

groundwater inflow

tunnel tightness