The removal of the barrier, which was placed to facilitate construction of both segments, paves the way for the next phase of the project - equipment installation, officials said.
The metro line project comprises four packages, three of which involve: construction and installation of the line's 2.6-kilometer (1.6-mile) underground segment (including three underground stations); construction of the line's elevated segment; and installation of the line's equipment, locomotives and trains.
Huynh Hong Thanh, deputy head of HCMC's Urban Railways Management Board, said the removal of the barrier would allow for the line to be fully connected from the Long Binh Depot to the central Ben Thanh Station, with all three underground stations Ben Thanh, Opera House, Ba Son and the entirety of the underground segment integrated into the line.
The barrier's removal also marks the project's phase transition from the construction of the overall structure to the installation of the rail, electromechanical and signal systems along the entire line, as well as the installation of equipment and the completion of the stations.
The city has set a target for project completion to advance from its current 71 percent to 85 percent before the end of this year, and officially go into operation by the end of 2021.
When completed, HCMC's Metro Line 1 will run 19.7 kilometers from Long Binh in District 9 to Ben Thanh in District 1 with a total of 14 stations.
Work on the line started in August 2012, with the elevated segment being cleared in June 2018.
Following the underground segment's clearance, restoration work on Le Loi Street's surface and the park in front of the HCMC Opera House are scheduled to be completed before April 30.
The locomotives and trains for the line are expected to arrive in HCMC in June.
The Metro Line 1 project was approved in 2007 with a total investment of VND17.4 trillion ($750 million). This was raised to VND47 trillion ($2 billion) in 2010 after design changes and fluctuations in the exchange rate of the Japanese Yen, but the increase was not approved by the relevant ministries.
Last November, the National Assembly allowed HCMC authorities to approve a new total investment of VND43.6 trillion ($1.88 billion).