At 11:16 on February 10, after 1,100 days of hard work, the Zhongwei-Lanzhou Railway Xiangshan Tunnel was imported to the 1# inclined shaft with a small mileage of 3640 meters to achieve a hole, marking the progress of the construction of the Xiangshan Tunnel and laying a solid foundation for the opening of the zhonglan railway in 2022.
The small mileage of the Xiangshan Tunnel from the inlet to the 1# inclined shaft has crossed the fault fracture zone four times and the gas section once, and the surrounding rock at the site has changed frequently, covering the grade III.-V. surrounding rock. The construction is affected by the fault zone, the gas section and the surrounding rock pore water, fissure water and other factors, the maximum inrush water per day up to 5700 cubic meters, equivalent to the water storage capacity of two standard swimming pools, exceeding the normal water inflow of 16 times, the construction also appeared many times collapse, initial branch deformation, construction safety risks, high difficulty.
In the face of complex geological conditions, in order to ensure the safe and orderly progress of construction, China Railway Lanzhou Bureau Group Co., Ltd. strengthened the management of project construction and supervised the implementation of key problems for rectification. Yinchuan Engineering Construction Headquarters has organized design and construction units to conduct on-site surveys, research and demonstration for many times, continuously optimized the construction organization plan, strictly followed the construction principles of "pipe advance, short advance, weak blasting, strong support, early closure, and diligent measurement", adopted the construction process of pipe shed + radial grouting, and arranged special personnel to take turns to monitor the on-site construction for 24 hours, increase the frequency of construction monitoring and measurement, strictly control the safety step distance, and ensure the construction quality and safety progress.
In particular, since November 2021, the Yinchuan Engineering Construction Headquarters has organized the "60 days of large trunk, comprehensive attack on the Xiangshan Tunnel, and fully achieve the phased goal" offensive activities, as of February 10, the Xiangshan Tunnel palm surface excavation has completed 17.16 kilometers, the remaining 0.6 kilometers, the upward arch has completed 16.3 kilometers, the remaining 1.46 kilometers, the second lining has completed 15.59 kilometers, the remaining 2.17 kilometers, and the overall excavation has maintained a good momentum. (New News Daily reporter Zhao Rui correspondent QiangKe)