The second section of the Purple Line Extension Transit Project includes 2.59 miles of additional tracks to Metro’s Rail system and two new stations at Wilshire/Rodeo and Century City/Constellation. The project received full Federal funding from the U.S. Department of Transportation in January 2017 and was under construction. Construction for Section 2 was planned to begin in 2018. The extension is expected to begin operations by 2025 and will continue the Purple Line from Miracle Mile through Beverly Hills and into Century City.

The deck beam which used in this project were fabricated and under strict control of CNOOD management team. General information were as below;
Products Description : Welded Fabrication Deck Beams with Stiffeners
Standard & Grade: ASTM A572 Gr.50, AWS D1.5:2015 Fracture Critical Endorsement
Total Weight: 1900 MT
Thickness: 25.4~82mm

Project Challenges

1. AWS D1.5 fracture control welding standard, and the production time was during winter, it was a big challenge to guarantee the welding quality;
2. The production lead time is tight, the shipping time had been determined in the middle of the production, and the delivery time was under great pressure in the latter part of the production;

Our Solutions

1. Increase QA/QC personnel and strictly follow the standards. The project manager had obtained the American Welding Society Inspector (CWI) qualification certification, unified and coordinated deployment, and hired a third-party TRC inspector to control the entire process to ensure that the quality is better than the standard requirements;
2. In the later stage of the project, CNOOD management team coordinate production resources, optimize production sequence, communicate in-depth with supplier leadership, ensure that the production center of gravity was tilted, and finally all goods arrived at the port before the ship date.

Conclusion

AWS D1.5:2015 Fracture Critical Endorsement is the high requirement among US bridge standards. Through the unified thinking of the CNOOD team, careful deployment, and scientific organization, many difficulties were overcome during the fabrication process, and the fabrication tasks were completed safely, efficiently and with high quality, which was unanimously affirmed by the client, the supervisor and the owner.