On the morning of May 14, the first retaining pile was drilled at Yanbei Road Station, located at the southeast corner of the intersection of Yanbei Road and Yanyuan Road, marking the official start of civil construction for the entire Phase I of Lanzhou Rail Transit Line 2. Lanzhou's rail transit construction has thus entered a stage of dual-line parallel progress.
Phase I of Line 2 has a total length of 9.06 kilometers and 9 stations
Phase I of Lanzhou Rail Transit Line 2 (from Dongfanghong Square to Yanbei Road) has a total length of 9.06 kilometers and includes 9 stations: Dongfanghong Square Station, Youdian Building Station, Railway Station Station, Bus No. 5 Company Station, Dingxi Road Station, Wulipu Station, Yannan Road Station, Yanyuan Road Station, and Yanbei Road Station. Among them, Dongfanghong Square Station and Wulipu Station have been designed and constructed simultaneously with Phase I of Line 1. The line also includes one parking lot, one main substation, and a control center shared with Line 1.
It is reported that the average station spacing of Phase I of Line 2 is 992 meters, with a maximum spacing of 1,322 meters and a minimum spacing of 610 meters. The line has a total of 5 transfer stations: Dongfanghong Square Station and Wulipu Station are transfer stations between Lines 1 and 2; Railway Station Station is a transfer station for Lines 2, 3, and 5; Yanyuan Road Station is a transfer station between Lines 2 and 4; and Yanbei Road Station is a transfer station between Lines 2 and 3.
Phase I of Line 2 will use Type A trains with 6-car formations. The estimated project cost is 9.078 billion yuan, and the total construction period is planned to be 54 months, with trial operation expected in September 2020.
Currently, the civil construction, supervision, and third-party measurement and testing units for Phase I of Line 2 have all entered the site and are carrying out preliminary preparations such as surrounding environment surveys, tree relocation, and site setup.
Four major difficulties faced during construction through the central area of Chengguan District
According to Sun Hongbin, deputy general manager of Lanzhou Rail Transit Co., Ltd., the main feature of Phase I of Line 2 is that it forms a cross structure and U-shaped connection with Phase I of Line 1 in the central area of Chengguan District (intersecting with Phase I of Line 1 at Dongfanghong Square Station and Wulipu Station). Once completed, it will form a local rail transit network. In terms of construction methods, Phase I of Line 2 is entirely underground, and all 8 sections will be constructed using the shield tunneling method.
According to Sun Hongbin, the section from Xiguan Cross to Wulipu on Phase I of Line 1 is all red sandstone geology. Based on preliminary surveys, Phase I of Line 2 will also face red sandstone geological challenges during construction. To this end, all participating parties have summarized the construction experience under red sandstone geology encountered during Line 1 construction, and have developed more targeted special designs from design and retaining structure forms to water stoppage and dewatering during foundation pit excavation. The main route of Phase I of Line 2 passes through the central area of Chengguan District. In addition to unfavorable geological conditions, construction will also face difficulties such as balancing construction with road traffic, protection and relocation of underground pipelines, and passing under the South River Channel and dense buildings.
Forming a cross structure with Line 1 within the central area of Chengguan District
It is reported that Phase I of Lanzhou Rail Transit Line 2 and Phase I of Line 1 are part of the recent Lanzhou rail transit construction plan approved by the State Council on June 9, 2012. They are also important components of Lanzhou's smooth traffic project and have been included in Lanzhou's 13th Five-Year Plan.
After completion, Phase I of Line 2 will form a cross framework with Phase I of Line 1 within Chengguan District, initially forming a rail transit backbone network in the central area of Chengguan District. This is of great significance for improving urban traffic functions, alleviating traffic pressure in the central area of Chengguan District, enhancing the city's agglomeration, radiation, and driving functions, and providing convenient and fast travel channels for citizens. By then, Lanzhou's central urban area comprehensive transportation system, with public transit as the main body and modernization and integration, will be further improved.