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.