As the New Year approaches, good news about Qingdao Metro construction keeps coming. On December 28, the shield tunneling for the section between Jiaozhou North Station and Jiaodong Airport Station of Qingdao Metro Line 8 was successfully launched. It is expected that the dual-line construction will be completed by the end of January 2019, marking that the first section outside the airport section of Metro Line 8 has entered the fast track. It is understood that Metro Line 8 has a total of 67 work sites, of which 49 have started construction so far, with a start rate of 73.1%. After opening, it will take only 50 minutes from May Fourth Square to Jiaodong Airport.

　　"The shield machine used this time is 85 meters long, weighs 500 tons, has a cutterhead diameter of 6.28 meters, and a thrust of 3,900 tons. With the shield machine, the daily efficiency can reach at least 9 meters, and at peak times over 20 meters, which is about 10 times faster than the drill-and-blast method," said Fan Xiaomin, chief engineer of the B1 package 01 work area project of China Construction Port Engineering Co., Ltd. on December 28.

　　It is reported that the section between Jiaozhou North Station and Jiaodong Airport Station is one of the first work sites of Line 8 to start construction, undertaken by China State Construction Engineering Corporation. The section is adjacent to the under-construction Jiaozhou North Railway Station of the Jinan-Qingdao High-Speed Railway. The shield tunneling section is about 1.6 kilometers long and runs parallel to the under-construction Jinan-Qingdao High-Speed Railway. After completion, it will enable close transfer between Jiaozhou North Station and the national railway Jiaozhou North Station. According to the plan, the shield tunneling of the parallel section will be completed before the joint debugging and testing of the Jinan-Qingdao High-Speed Railway.

　　The shield tunneling section project from Jiaozhou North Station to Jiaodong Airport Station of Metro Line 8 includes Jiaozhou North Station and the section between Jiaozhou North Station and Jiaodong Airport Station. Jiaozhou North Station is located under the station square on the south side of Jiaozhou North Railway Station, arranged in an east-west direction. At this station, Line 8 can achieve same-platform transfer with the Qingping Intercity Line. The station is 344 meters long, 40.8 meters wide, and about 16 meters deep, and is constructed using the open-cut sequential method.

　　The section between Jiaozhou North Station and Jiaodong Airport Station includes a 458-meter-long open-cut section and a 1,566-meter-long shield tunneling section. The shield tunneling section runs from the end of the open-cut section to the No. 1 interval ventilation shaft of the Jiaodong Airport pre-embedded project. The section is 1,575.55 meters long. One shield machine will first construct the left line, and after the left line is completed, it will be relocated for a second launch to construct the right line.

　　Metro Line 8 passes through many complex geological areas such as rivers, tidal flats, and sea areas. Among them, the section between Dayang Station and Qingdao North Station crosses the Jiaozhou Bay sea area, with a sea section of about 5.5 kilometers, which brings great difficulty to construction. "The geology of Metro Line 8 is mainly moderately weathered argillaceous sandstone, with locally harder andesite. Overall, it is relatively suitable for shield tunneling. According to the plan, the left line will be completed in mid-June next year, and the dual lines will be completed by the end of January 2019," said Fan Xiaomin.

　　Niu Dachuan, deputy director of the Engineering Management Office of Qingdao Metro Line 8 Company, introduced that Metro Line 8 has a total of 67 work sites, of which 49 have started construction so far, with a start rate of 73.1%. Of the 18 stations on the entire line, excluding 3 stations that are agent-constructed or already built, 12 of the remaining 15 new stations have started construction. The demolition quantity of Hongdao Railway Station is being counted, the preliminary geological survey of Cangkou Station has been completed, and the demolition work of Yanjiashan Station is about to start. All 36 work sites of the first phase of green migration have been completed. Pipeline relocation work is underway at Dajian Station, Science and Technology Museum Station, Dayang Station, and Jiaozhou North Depot, with a cumulative completion of 17.1%.

　　The main line of Metro Line 8 is about 60 kilometers long, mainly underground. The entire line has 18 stations, starting from Jiaozhou North Station and ending at May Fourth Square, with transfers to Metro Line 1, Line 2, Line 3, and other lines. The maximum operating speed of the underground section of this line reaches 120 kilometers per hour, and it takes only 50 minutes from May Fourth Square to Jiaodong Airport.