Construction Progress of Metro Line 4 Tunnel from Xiaotun Station to Jindingshan Station

Yesterday at 1400 hours, with the cutter head of "Chuncheng 5" shield machine slowly breaking through the earth, the Left-Line tunnel of the shield section between Xiaotun Station of Kunming Rail Transit Line 4 and Jindingshan Station, constructed by Guangzhou Railway Engineering Bureau Urban Rail Engineering Co., Ltd., was successfully connected 15 days ahead of the planned construction period.
       The left tunnel of the shield section between Xiaotun Station and Jindingshan Station on Metro Line 4 is 1456.964 metres long. Along the section, roads, schools, residential districts, factories and smart parking lots are crossed. Because of the complex geological conditions, mainly through the red clay layer, full weathering, strong weathering, medium weathering basalt section, abundant groundwater, the excavation process is prone to eccentric wear, gushing and other phenomena, which is listed as one of the three key control tunnel projects of Line 4. In order to ensure the smooth completion of the project task, the project department organized several expert consultation and demonstration meetings to demonstrate and evaluate the performance of the shield machine for a long time before the start of the shield machine. Finally, it decided to remake the cutter head and high strength alloy cutter adapted to the complex geological interval. Especially since the start of the shield machine on April 1, facing many difficulties, such as tight construction period, heavy tasks, high safety and quality risks, the project department has organized scientifically to meet the difficulties and carried out 24-hour uninterrupted construction according to the method of "people stop, time is sufficient and space is full", continuously optimizing the construction scheme and ensuring the construction. The work went smoothly and orderly.