Abstract: The mutual compensation of random errors is often neglected in traditional analytical method of break-through error estimation for underground traverse with gyro observation,and it leads to an overestimation of the error.Based on Monte Carlo random simulation technology,a break-through error estimation method is proposed.The method is tested on an equivalent mock-up network of the tunnels associated with the Hong Kong-Zhuhai-Macau Bridge.The results prove that the proposed method could effectively estimate break-through error,and has a good application effect for underground traverse with gyro observation.

Key words: gyro azimuth, underground traverse, break-through error estimation, immersed tunnel, Monte Carlo random simulation