Abstract: Taking the surrounding rock of TBM tunnel as a research object， the 3D laser scanning technology is used to detect the shaping quality of TBM tunnel. An automatic detection method of TBM tunnel shaping quality was proposed based on the 3D laser scanning technology. The 3D scanning device composed of a Pan-Tilt and a 2D laser scanner is installed on the main beam of the TBM. The Pan-Tilt can quickly rotates 90° towards the cutter head with the 2D laser scanner， and can convert the 2D point cloud acquired by the scanner into a 3D point cloud in real time， then the computer performs preprocessing， such as tunnel axis calculation， filtering and interception on the point cloud， and calculates the flaking and collapse of the surrounding rock using section extraction and piecewise cubic Hermite interpolating polynomial. Parameters of the tunnel shaping quality can be given， thus the tunnel shaping quality can be accessed. The feasibility of the TBM tunnel shaping quality detection method was verified through an engineering example. By adopting this method， the tunnel shaping quality can be detected simultaneously during the TBM construction process， and a digital measurement system can be formed.

Key words: tunnel boring machine(TBM) tunnel; 3D scanning; tunnel shaping quality; Hermite interpolation