Recently, the upbound tunnel of the Guanglan Road–Gaosi Road Station section under Civil Works Lot 5 of Shanghai Rail Transit Line 21 Phase I was successfully launched. With this, both the upbound and downbound tunnels of the section have been launched.

The Guanglan Road–Gaosi Road Station section is constructed by the shield tunneling method. The downbound tunnel of the section is 944.514 meters long. The excavation diameter for this drive is 6.76 meters, and new-type socket-type segments are used. The section will pass beneath important locations such as rivers and revetments. The launching section is an upslope plus curve launch, imposing high requirements on construction safety and quality.

The Fourth Branch Company implemented the relevant high-quality development requirements of the Group Company, urged the construction unit to study at relevant projects, and formulated the "Standardized Construction Implementation Rules for New-Type Socket-Type Segments" to guide construction. It also set strict requirements for shield machine advancement parameters, segment assembly quality, and settlement control of important pipelines and buildings (structures) along the section. All participating units are required to carry out construction and management strictly in accordance with design requirements and plans, and a shield remote information monitoring system has been established to facilitate later real-time back-office monitoring of the entire shield construction process and timely grasp of construction conditions.

On the basis of consolidating existing achievements, the Fourth Branch Company will subsequently continue to implement refined management measures, control both quality and safety standards well, and steadily advance the construction of Shanghai Rail Transit Line 21 Phase I with "high standards and strict requirements."