Group 1 - The "Pingzhang East No. 3" shield machine, constructed by China Railway Third Bureau, successfully commenced operation on August 1 in Shenzhen Pingshan [2] - The shield machine has a diameter of 14.34 meters, a tunneling length of 3,850.6 meters, and a maximum burial depth of 62.5 meters, designed for a single-tube double-track tunnel [2] - The Shenzhen-Dongguan Railway, starting from Shenzhen Xili Station to the Shenzhen-Dongguan Special Cooperation Zone and connecting to the Guangshan Railway at Shenzhen-Dongguan Station, has a total length of 125.5 kilometers and is a key part of the national "Eight Vertical and Eight Horizontal" high-speed rail network coastal corridor [2]