'CREC 1005' is a 'sharp tool' specially designed by China Railway Engineering Equipment Group Co., Ltd. for Zhonggong Kejiang (Beijing) Construction Co., Ltd. The equipment will serve the No.2 entrance of Yuntai Garden Station of Guangzhou Metro Line 11 Project of China Railway First Group Co., Ltd. The construction area is relatively complex. It is close to the foot of Baiyun Mountain in the northwest, Luhu Lake in the southwest and Guangzhou City in the southeast. The underlying stratum is mainly silty clay and sandy clay, and the jacking distance is 57.5m. Guangyuan Road above the tunnel is the main road in Guangzhou, with heavy traffic flow, thus it sets high requirements for land settlement control and adds difficulty to construction.
The rectangular TBM 'CREC1005' has a width of 6.02 meters, height of 4.32 meters and weight of 250 tons. It adopts the combined excavation design of three cutterheads behind the leading three cutterheads, and the excavation rate reaches 92%. The equipment will continue to serve Guangzhou Metro projects in the future.
The excavation section of Tianfei No. 1 TBM is 12.6m wide and 7.65m high. It adopts a seven-cutterhead combination arrangement with four cutterheads behind the leading three cutterheads. The cutting areas of adjacent cutterheads cross each other, and the cross-section excavation coverage rate reaches 95%. The machine has stronger rock breaking ability and tunneling efficiency that can excavate in high-strength hard rock stratum and 100MPa rock stratum. At the same time, it has very little disturbance to the ground, ensuring its safe crossing of the Hangzhou-Shenzhen railway.
After the machine enters the construction site, the technical service team of China Railway Engineering Equipment Group Co., Ltd. has overcome many difficulties such as road transportation and assembly, planned in advance and organized scientifically against tough problems, such as upper soft and lower hard stratum, high rock stratum strength, large distribution of boulders, high frequency of crossing the existing Hangzhou-Shenzhen railway, proximity between the top and the existing railway business line, difficult settlement control and high construction risk. With these efforts, the established nodes of 'Tianfei No.1' initial tunneling are completed as scheduled.
