Abstract: Tunnel excavation will cause surface and subsurface settlement. Studying the law of formation movement is of great significance to determine the risk level of buildings and protect adjacent buildings.Firstly,the calculation model of risk zone is obtained based on Peck's formula considering the settlement and inclination of buildings caused by subsurface settlement trough. Secondly, the influence rules of tunnel diameter D, foundation depth d and ground loss ratio V_L on the size of the building risk zone are analyzed, and the boundary values (C/D)₀ and (x/D)₀ of risk zone are deduced. Finally, according to different risk control levels, a preliminary risk assessment method for adjacent buildings during tunnel excavation is proposed, and the risk zone is divided into four zones. The risk zoning method proposed in this paper is simple and highly-efficient as only four parameters are needed: tunnel diameter D, ground loss ratio V_L, tunnel's buried depth Z and coefficient i of settlement trough width. The method also reflects the influence of different parameters on the change of risk zone. The research findings provide reference for preliminary judgment and risk prediction of the impact of tunnel excavation on adjacent buildings' safety.

Key words: tunnel engineering, Peck's formula, settlement trough, adjacent buildings, risk zoning