Early investigations found numerous voids and extensive soft spots on the site.
Kent Highways started repair work on the void when it opened up on May 28 and have spent an estimated 8,000 hours on making the busy passage safe.
KCC cabinet member for highways Mike Whiting said: “The significant work we’ve done with ground stabilisation and renewal of utility infrastructure will increase resilience against future failure and prevent the need for any further utility works.
“Whilst I appreciate residents’ frustration with the time it has taken, this has been a huge undertaking and something we have never dealt with before. It required specialist contractors which are not always readily available, as well as significant planning.
“I’d like to say thank you for the hard work that has gone into ensuring the road is once again safe and open for use.”
