The bearings between the bridge deck and the support piers of Hill Bridge, at the junction of the M876 and the M9 near Stenhousemuir, need to be replaced.
Safety barriers at the sides of the overpass will also be upgraded.
To allow the improvements to be made, hard shoulders and lanes will be closed overnight, while a 50mph speed limit will be introduced.
Hill Bridge carries the eastbound carriageway of the M876 over the M9 where the two motorways connect at Junction 8.
Transport Scotland’s operating company, BEAR Scotland, will carry out the work, which will begin on Monday, November 22.
To replace the bearings, a temporary jack system will be installed to lift the bridge deck by several millimetres.
These jacks will hold the bridge securely in place while the old bearings are removed using hydrodemolition (high-pressure water jets).
BEAR Scotland will also carry out concrete repairs on the bridge’s support piers, renew paintwork on the steel beams and upgrade the safety barriers around the central support pier.
Chris Tracey, BEAR Scotland’s south east unit bridges manager, said: “The existing bearings and parapet system of the Hill Overbridge on the M876 are nearing the end of their design life.
“It is essential to replace them now to ensure the long-term integrity of the structure.
“Hard shoulder closures, overnight lane closures and a 50mph speed limit will be required throughout these works in order to keep the workforce safe, however, we have planned the project to ensure that two lanes in each direction remain open on the M9 during the daytime. The westbound M876 will also be unaffected.
“It will be necessary to close the eastbound M876 on four separate nights when we jack up the bridge deck to allow the old bearings to be removed.
“The first such closure is expected to take place on the night of Thursday, December 2. We’ll share full details of timings and diversion routes closer to the time once dates are confirmed.”