On November 9, 2021, the start of the Tongluoshan Tunnel Project, Phase 9 of the Urban Rail Express Line 27 Phase I Project undertaken by the China Construction Fifth Engineering Bureau and China Construction Tunnel, was officially held in the 2# construction channel of the project. According to reports, this is the first starting point for Chongqing Rail Transit Line 27.

Chongqing Rail Transit No. 27

According to reports, Chongqing Rail Transit Line 27 has a total length of 51.829 kilometers with 14 stations, starting from Bishan in the west, passing through Jinyun Mountain in the east, passing Huxi Station, University Town South Station, Zhaishanping Station to Xiyong Station. Pass through Zhongliang Mountain to Ciqikou Station and Shapingba Station. After exiting the station, turn to the southeast via Shiqiaopu Station and Dapingxi Station to Chongqing Station, then turn south and cross the Yangtze River to Houpu Station and Nanping Station, then turn east and cross the Tongluo Mountain, pass Guangfu Avenue Station to Chongqing East Station. One of the elevated stations is Bishan Station (implemented by the Bitong Line of the Suburban Railway), and the remaining 13 are all underground stations with Chongqing East Depot and Bishan Parking Lot.

According to the construction party, the total length of the Tongluoshan Tunnel on Metro Line 27 and No. 9 bid is 4.6KM. It is a full-line control project. Mined-out areas and karst areas with high pressure and rich water have high risks. In order to realize the smooth start of construction, the project united and cooperated, actively connected with relevant units, went through procedures, and solved key issues such as land acquisition, water, electricity, and labor teams on the construction site.

The length of the construction general contracting project of this joint bid is 22 kilometers, including Bishan parking lot and entrance and exit lines, Bishan Station (not included) ~ Ciqikou Station (including) section engineering and station engineering, etc., corresponding 4 construction tender sections including CQ27TJ01-CQ27TJ04.

The construction task of the CQ27TJ02 bid section undertaken by the consortium is 2 stations and 2 sections, mainly including the compound TBM method + mining method section of the Bishan station (excluding)-Huxi station section and a small number of subgrade projects, Huxi station, Huxi station The section between Xi Station and University Town South Station and University Town South Station is about 8.2 kilometers in length.

Huxi Station

Huxi Station is an underground two-story double-span (partially three-span) island-style open-cut station. It is interchanged with Line 17 at a "T-shaped" node. It is located at the crossroad of Daxuecheng South Road and Daxuecheng Middle Road. Xiang arrangement. The total length of the station is 375.869 meters, the main length is 280.550 meters, and the length of the wiring section in front of the station is 95.319 meters. The standard section of the station has a width of 24.9 meters, a depth of 18.91 meters in the center line of the station, and a roof covering about 3.5 meters.

University Town South Station

Daxuecheng South Station is a two-story, three-span island-style station, interchange with Line 15 in a "T" node. It is located on the west side of the intersection of Daxuecheng South Road and Daxuecheng Dongyi Road. It is arranged along Daxuecheng South Road in the east-west direction, with a total length of 244.874 The standard section is 24.1 meters wide and 16.7 meters high. The overburden of the station roof is about 3 to 5 meters, and the depth of the foundation pit is about 22 to 23 meters.

Huxi Station~University Town South Station

The length of the tunnel on the right side of the section is 1915.950 meters and is constructed by the composite TBM method; the length of the left tunnel on the section is 1915.513 meters, most of which are constructed by the composite TBM method. The construction section of the TBM section is 1613.13 meters long.

At the end close to the University Town South Station, a connecting line with Line 15 is set on the left side of the line, and the open-cut method + underground-excavation method is used for construction. The open-cut section is 96 meters long and the under-cut section is 206.50 meters long. The buried depth of the tunnel vault is about 10-22 meters. It is dominated by sand and mudstone and fill layers. The partial fill section is thick, most of which are shallow tunnels, and some are deep tunnels. The open-cut foundation pit is about 19-20 meters deep and is a rock-soil mixed foundation pit, which is supported by piles and internal supports.

Underground section and roadbed section of the interval between Bishan Station (not included) and Huxi Station

The underground section is divided into two sections. The first section passes through the Jinyun Mountains. The Jinyun Mountain tunnel is 3125 meters long. The tunnel entrance mileage is YCK1+030, and the exit mileage is YCK4+155. The YCK1+155~YCK1+285 section of the cave is an open-cut section. The section passing through the Zhongjinyun Mountain adopts a single-hole single-line structure and is constructed by drilling and blasting.

The second section passes through the Outer Ring Expressway and University Town South Road, with a length of 2485.581 meters. Except for the 20-meter composite TBM receiving tunnel at the small mileage end, which is constructed by mining, the rest are constructed by composite TBM.

The length of the section roadbed is 89.75 meters. Among them, the length of the entrance roadbed of the Jinyunshan Tunnel is 14.75 meters, and the length of the exit roadbed of the Jinyunshan Tunnel is 75 meters.

In the future, after Chongqing Rail Transit Line 27 is completed and put into operation, three troughs and valleys will be built to communicate efficiently in the east-west direction, connecting Shapingba Station, Chongqing Station, Chongqing East Station and other important gateway hubs, realizing the rapid conversion of traffic inside and outside the city, and better solving Chongqing Traffic problems in the central city support the adjustment of urban spatial structure and enhance the city’s carrying capacity and competitiveness. Editor/He Yuting