Abstract: The construction quality problems such as void behind the secondary lining, uncompacted concrete, insufficient thickness and intensity, cracking of construction seam, etc. often exist in tunnel. During the construction of a tunnel on ZhangjiajieJishouHuaihua Railway under construction, the 3D laser tunnel scanning and measurement system is used to ensure that the primary support crosssection is within limit; the laser positioning and magnetic welding are used to improve the fixation effect of waterproof board; a new type of trolley material system is developed and used to realize the tunnel arch wall lining concrete automatic laying by window pouring; the brake hole is used, the monitoring device and the liquid level device are installed in the crown to effectively prevent and control the void in the crown; the arch vibration mode and construction technology of construction seam are optimized; the technology and management measures of new method for quality control of tunnel secondary lining are formulated and implemented. By adopting the above measures, the missing thickness of secondary lining is zero, the void rate of the arch is reduced to less than 5%, the strength of the secondary lining concrete meets the design requirements, and the overall construction quality is greatly improved, which guarantees the safety of the tunnel construction and operation.

Key words: railway tunnel, secondary lining quality control, 3D laser scanning, new lining trolley, construction seam control, crown void prevention, automatic spray curing