Chongqing, also called as mountain city, is mainly hilly and mountainous, with mountainous area accounting for 76%. In recent years, the city has been committed to solving the problem of urban traffic congestion. Construction of rail transit and highway has always been in progress, and the most important one is the construction of underground tunnels. However under the cover of high-density buildings on the ground proposes extremely high requirements for the disturbance of surrounding rock and construction safety.
After repeated comparison and comprehensive evaluation of the construction efficiency, product performance, company strength and product cost performance by relevant construction units in Chongqing, XCMG cantilever tunnel boring machine was finally selected for underground construction.
In 2017, XCMG XTR6/260 heading machine was put into use in the 8th section of Chongqing Rail Transit Line 9. For minimum disturbance to the whole and local surrounding rocks, and no excessive earthwork of excavation or noise, it did not interfere with the surrounding buildings and residents, and achieved a very good reputation. After that, the construction unit introduced several XCMG tunnel boring machines successively. As of June 2019, XCMG XTR6/260 were stationed in Chongqing Rail Transit, Highway and other projects for construction in succession.
At present, both the 8th section of Chongqing Rail Transit Line 9, Leijiapo Over-crossing tunnel, Chongqing Jiangbei Airport East Ring Tunnel, Beijing-Kunming Highway Shitigou Highway Tunnel and other tunnel projects in adopt mechanized excavation technology of cold excavation. With safe and efficient construction efficiency, XCMG boring machine was popular among the China Railway and China Railway Construction and other large-scale companies that have expressed strong interest in this construction technology and hope to use this advanced equipment to achieve greater benefits in the future projects.
In May, 2019, two units of XCMG XTR7/360, the largest cantilever tunnel boring machine in China, went to Chognqing to help the construction of Chongqing Dadukou Baihua Village Highway Tunnel for 11th China Railway Construction Bureau. Located in a bustling urban area, this project was planned to commence in 2018. Due to the subway station and residential building above the project, the traditional technology was unable to meet the needs of construction. The construction was very difficult and even faced shutdown. After surveying several construction site of tunnel boring machine and comparing the equipment parameters between XCMG and other factories, 11th China Railway Construction Bureau immediately decided to use the construction scheme proposed by XCMG, and purchased two units of XTR7/360 at both ends of the tunnel at the same time. After one month of product construction statistics and analysis, XCMG cantilever boring machine has high efficiency and controllable cost, the pressure of tight construction schedule has been greatly relieved.
XCMG XTR series cantilever boring machine is a new rock roadway boring equipment integrated with cutting, running, loading, dust removal and spraying and developed for the needs of various tunnels. it is equipped with dust removal, rolling cable, intelligent safety protection and other devices, and widely used in the excavation of railway tunnel, highway tunnel, water conservancy tunnel, metro tunnel and various mine roadways.