Abstract: Through analyzing the measured values of in-situ stress field of Cangling tunnel area, reliable and representative of the actual measured points are selected as the object of the inversion regression. Using 3D numerical analysis combining with principle of regression analysis, the entire project area in-situ stress field distribution is obtained. Through comparative analysis between the regression and local measured values, it is found that apart from individual point appears difference, most of the measured points fit well and the distribution laws are roughly the same. The results indicate that stress-regression method is reasonable. On this basis, by using the stress-regression equation, the Cangling tunnel’s in-situ stress field distribution rule along the axial direction is obtained, and according to the angles of different sections of maximum principal stress and the tunnel axes directions, the tunnel stability is analyzed. Accordingly, further optimization of the route position of Cangling tunnel is proposed, so as to provide important basic data for tunnel design and construction.

Key words: highway tunnel, in-situ stress field, inverse analysis, numerical simulation