Group 1 - The Chongqing Liangjiang New Area-Changshou District Expressway Project has officially entered the tunneling phase for the left tunnel, with significant progress in various construction stages [1][7] - The first section of the roadbed, measuring 1200 meters, is now in the pavement construction phase, adhering to strict design specifications [3] - The mainline bridges, including Bridge No. 14 and Bridge No. 15, are under construction, with specific structural designs and complexities due to the terrain [4][5] Group 2 - The Yanjia Tunnel has a total length of 4450 meters for the left tunnel and 4460 meters for the right tunnel, with the left tunnel currently reaching 1433 meters [7] - The construction environment presents challenges due to poor geological conditions, including high gas areas and water-rich zones, necessitating innovative approaches and safety measures [7]