Repair work on a section of track hit by a 200-tonne landslip is a "temporary solution", rail bosses have warned.
A trackside wall collapsed near Liverpool Lime Street on Tuesday, effectively closing the station.
Services are expected to resume by 9 March.
Network Rail construction manager Jamie Williamson warned that permanent fix would involve closing the lines again, possibly at Easter or Christmas.
He said 50 people are working "round the clock" to remove 10-15ft (3-4m) from the top of the damaged wall.
Mr Williamson said he hoped engineers would be able to get down on to the tracks and start removing 20 tonnes of rubble from the lines over the weekend.
Then it will be a case of repairing the rails, the overhead power cables and the damaged signalling equipment, he said.
The section of trackside wall "loaded with concrete and cabins by a third party" fell, blocking all four lines into the station and evening leaving rubble strewn across the tracks.
Police are currently not involved in any investigations, but the Rail Accident Investigation Branch said a team of inspectors are carrying out a preliminary examination which will "help us determine if an investigation is necessary".