Abstract: The total length of the tunnel created during the water supply project in northern Xinjiang is 514 km, consisting of 18 open tunnel boring machine (TBM) clusters. Work on this scale is rare, both in China and abroad. To understand the boring law, the authors make a statistical analysis of the equipment parameters and related indexes, machine jamming, and the support of cluster tunneling over the past 2 years. The average monthly footage of the 18 machines used in the project was 385.2 m, the highest monthly footage was 1 136 m, the average utilization rate was 28%, 〖JP+2〗the average intact rate was 91%, the average failure rate was 9%, and the number of cutter changes per extension meter was 0.02~0.45, indicating that the equipment has good adaptability. However, there were also some problems, such as abnormal cutter wear, high belt and anchor drill failure rate. In the process of longdistance TBM cluster tunneling, targeted treatment measures should be taken according to different jam types and different water gushing conditions. The tunnel support form and support parameter design should be adapted to the construction characteristics of the equipment, and the equipment should also be improved during manufacturing according to problems that arise, such as bolting nonvertical rock surface. In general, the efficiency of TBM cluster tunneling is high, but there are still some issues, and it remains necessary to make continuous efforts to achieve the longterm safe and efficient tunneling.

Key words: super-long tunnel, TBM cluster, boring index, jamming treatment, support technology