On March 1, the left line of the Zheng-Hong shield tunneling section of the Chengdu Metro Line 19 project undertaken by Sinohydro Bureau 4 successfully surpassed 500 rings, marking another important milestone since work resumed.

　　The left-line tunnel of the shield tunneling section between Zhengxingwan Station and Honglian Station is 2,238.507 meters long and includes one ventilation shaft and four cross passages. The minimum turning radius is 1,314 meters, the maximum longitudinal slope is 25‰, and the cover depth ranges from 10 to 30 meters.

　　Since the project resumed work, in order to ensure orderly shield tunneling progress and complete all construction tasks with guaranteed quality and quantity, the project department has organized multiple safety, quality and technical briefings and special safety production meetings for crews and management personnel, accelerating shield tunneling progress while keeping safety and quality under control; further strengthened on-site construction management, refined construction plans, and carried out skills improvement training and education to reduce employees' restless mood during the Spring Festival holiday and help them settle down and devote themselves to metro construction; third, implemented an on-site shift handover system, organizing a handover meeting each morning and evening to clarify the construction task objectives and possible difficulties for the shift and propose detailed and feasible solutions, achieving seamless connection between day and night shifts.