There will be no rail services in or out of Aylesbury for the next 12 days.
Planned major engineering works will be carried out to re-build a failed drainage culvert.
Replacement buses will operate until August 18th.
Buses will also connect with trains at Princes Risborough and with London Underground Metropolitan Line Services at Amersham.
The advice from Chiltern Railways is check the National Rail website before travelling with strike action also affecting services across the network.