On March 2, the shield machine of the right line of the first phase of the B1 line of Tianjin Rail Transit Line 7 from the North Station Station to the Guangzhou Road Station (hereinafter referred to as the Cheguang section) was successfully launched. It marks that the Cheguang section has fully entered the shield construction stage, and the builders have devoted themselves to the resumption of production after the holiday with a full mental state, and have made full efforts to win the "good start" in the first quarter and play the "Endeavor Song" of the New Year.

The "Shenlong No. 8" shield machine is an earth pressure balance shield machine, with a total length of 84 meters, a cutterhead diameter of 6.84 meters, and a total installed weight of about 500 tons, which undertakes the excavation task of about 2,000 meters of the right line tunnel in the Cheguang section, and is the longest section of the rail transit line B1 in the coastal main urban area. The topography and geological environment of the area is complex, mainly silty soil layer, and it is necessary to cross Hebei Road, Baoshan Road and other traffic lines along the line, involving a number of existing underground pipelines, and close to Hebei Road overpass and other building groups, so it has a heavy responsibility to protect the surrounding environment and social order.

In order to ensure the smooth launch of the shield machine, the project overcame many difficulties such as the narrow starting site, complex geological environment, and tight construction period. With the strong support of the Binhai New Area Government Service Office and the Housing and Urban-Rural Development Commission, and under the organization and deployment of the rail company, the construction unit increased the allocation of construction resources, optimized the construction plan, made the process smoothly connected, and effectively reduced the impact of the narrow site on the hoisting operation. In the face of the complex geological environment, combined with professional construction experience, the selection of the shield machine was studied in depth, and targeted adjustments were made according to the construction conditions and geological conditions of the excavation section, so as to pre-control the adverse effects of the geological environment on the shield tunneling.

In addition, while doing a good job in pre-job safety education and training, technical disclosure and other related work, we will carry out safety inspections on the construction site, eliminate potential safety hazards in a timely manner, and make every effort to ensure the investment of key elements such as personnel, equipment and production materials, so as to ensure that the key node work objectives are completed on schedule.

Through the above measures, the project construction team finally gnawed the "hard bones" and safely and efficiently completed various key processes such as the pre-embedding of the cave door, the assembly of the shield machine hoisting and going downhole, the equipment commissioning and the acceptance of the starting conditions, and successfully achieved the goal of the shield starting node.