United Utilities has been working at the Mancunian Way site over the weekend to assess the collapse.
A repair plan is "now in place" to stabilise the hole and make it watertight so engineers can repair the damage.
The road will remain closed in both directions while work takes place.
A spokesman for Manchester City Council said: "This initial phase of work could take up to 10 days, but until we are completely satisfied that the area is safe the section of the Mancunian Way will remain closed in both directions."
A diversion remains in place via London Road, Fairfield Street, A665, Hyde Road and Downing Street.
At the weekend, members of the public were warned not to cross a safety cordon as engineering work was being "hindered".
About two weeks' worth of rain fell in about six hours in Manchester on Friday before the hole appeared.
Tony Griffiths, of United Utilities, told the BBC: "An awful lot of rain fell on Friday - a few days' worth - which washed the ground material beneath the carriageway, causing the highway culvert to fail. Debris washed into the sewer, causing a domino effect leading to the collapse."
Mr Griffiths said the hole is still "quite unstable" and needs to be filled in before work can be carried out.

Ronan O'Mahony and James Cronin both notched two tries with Tommy O'Donnell and the Scannell brothers Niall and Rory also touching down for Munster.
Derick Minnie scored a first-half try for Zebre as Munster led 24-7 at the break with Lloyd Greeff also scoring for the Pro12's bottom club in Parma.
The Italian club have lost 16 of their 17 Pro12 matches this season.
Ireland hooker Niall Scannell finished off a maul to open Munster's account in the third minute before his fellow international O'Donnell extended the lead on 18 minutes.
After wing O'Mahony's first try, Minnie replied for Zebre on the half-hour mark before a Tyler Bleyendaal penalty left Munster 17 points clear at half-time.
Munster centre Scannell joined his older brother on the scoreboard with the first try of the second half to ensure his side a bonus point, before O'Mahony secured his brace after Marcello Violi was sin-binned for the hosts.
Despite their numerical disadvantage, Zebre reduced the deficit to 12 points through a converted try from South African Greeff with just under 25 minutes to play.
But Munster quickly reasserted their authority as prop Cronin marked his comeback from injury with two tries in the final 20 minutes, both converted by Rory Scannell.
Zebre: D Berryman; K Van Zyl, T Boni, T Castello, L Greeff; S Bordoli, M Violi; B Postiglioni, O Fabiana, B Le Roux; G Koegelenberg, V Bernabo (capt); M Mbanda, J Meyer, D Minnie.
Replacements: S Tobias, A De Marchi, G Roan, J Furno, F Ruzza, C Engelbrecht, M Pratichetti, G Palazzani.
Munster: A Conway; D Sweetnam, J Taute, R Scannell, R O'Mahony; T Bleyendaal, D Williams; D Kilcoyne, N Scannell, J Ryan; D O'Callaghan, B Holland (capt); P O'Mahony, T O'Donnell, J O'Donoghue.
Replacements: R Marshall, J Cronin, S Archer, D O'Shea, C Oliver, A Lloyd, D Johnston, D Goggin.
A busy Manchester road which partly collapsed when a sinkhole appeared is to remain closed for at least 10 days.
[NEXT_CONCEPT]
Munster continued their march towards the Pro12 play-offs as they earned a 50-14 bonus-point away win over Zebre.