Grouting at the Westlink Project –Gothenburg, Sweden. The Challenges and How These Are Met-Paper

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The West Link is an approximately 8 km railway project beneath central Gothenburg, including 6 km of tunnel and three new stations. About 4 km of the tunnelling is through crystalline rock. Because groundwater drawdown could damage nearby buildings and infrastructure, allowable inflows are stringent—generally 2–5 litres per minute per 100 m of tunnel.<br /><br />The grouting design addresses variable rock fractures through three classes (IK1–IK3), using different grout mixes, staged drilling and injection, and control holes with water-loss measurements. Leakage is also monitored in tunnel weirs, while groundwater levels around the works are tracked. Results guide decisions on additional grouting.<br /><br />Experience from service tunnel ST210 in the Haga contract showed that a modified approach, IKX, could reduce the number of grouting rounds and speed construction while meeting the adjusted leakage goal. Measured inflow remained below the legal limit, and monitoring found no adverse effect on groundwater levels.<br /><br />In the Korsvägen contract, service tunnels generally achieved low inflows. Two tunnels were well below their limits; one was close to its target, with leakage concentrated in particular areas. The findings highlighted how fracture orientation and connectivity can make some water-bearing structures difficult to intercept and grout.<br /><br />Overall, the service-tunnel results are promising, and monitoring and adaptive grouting have helped balance sealing performance, construction time and cost. The most difficult work remains ahead: large, complex station excavations with limited rock cover in sensitive urban surroundings. The authors emphasize that continuous measurement, timely design adjustments, and close cooperation among contractors, construction managers and designers are essential to meeting the project’s leakage requirements.

Keywords

West Link

Gothenburg railway project

tunnel grouting

groundwater control

crystalline rock

leakage monitoring

service tunnels

fracture orientation

adaptive grouting

station excavations