Crossrail restarted most of its piling and utility diversion work on Monday after an explosion last Wednesday.
Piling and utility excavation was stopped following an electrical explosion on its High Holborn site in central London.
The incident was caused by a strike on an underground cable at lunchtime on 12 December. It is unknown how the accident occurred.
The Health & Safety Executive is investigating the incident but further details are unavailable until the inquiry is complete, said a Crossrail spokesman.
Barhale employee Barry McGeehan was injured in the explosion and is being treated for burns.
Following the explosion Crossrail said instructions had been issued to all contractors repeating procedures for approving and undertaking below ground works.
The Crossrail spokesman was unable to confirm what detailed information was used to locate and identify services, whether sites had a 3D model available and how many unknown or unidentified services it had been finding.
Crossrail declined to comment on how the stoppage would affect construction schedules but there remains an enormous amount of services location, strengthening and diversion to be done.