Abstract: The urban tunnel has the characteristics of highrisk, such as poor geological conditions, long construction period, large scale, and complex surrounding environment, as a result safety monitoring design aspects are proposed in this paper: Firstly, it is necessary to determine the adoption of technical basis by using the following aspects; focusing on the risk analysis of site geological conditions, construction method characteristics, and surrounding environmental conditions, sorting out potential engineering risk sources, dividing monitoring scope, determining monitoring levels and objects. Further, the determination of the monitoring items, monitoring frequency, etc. can be obtained. Secondly, based on the determined monitoring items, corresponding monitoring methods and technical means are selected or recommended to determine the accuracy of engineering monitoring. Finally, based on technical specifications or engineering experience, monitoring control values are therefore determined. The segmental tunnel between Lianban Station and Lianhua Intersection Station of Xiamen Metro Line 1 is presented in this paper as the case history. The design concept and analysis of safety monitoring are also introduced in detail.

Key words: HighRisk, Urban Tunnel, Monitoring, Design