Through investigation and in-situ measurement of crustal stress in tunnel location

rather large tectonic stress is ascertained in the tunnel region at first. Because of core sample break

only stress of disturbed area is measured in the tunnel. In the process of 3-dimension numerical modeling

the course of vertical erosion by the Wujiang River is modeled in order to reflect the effect of topographic form on crustal stress. And using the method of pilot calculation to adjust coefficient of horizontal pressure

then appropriate initial stress is determined. Making calculated results coincide with the data measured in-situ

the rational coefficient and crustal stress is obtained. Numerical calculation covers the shortage of in-situ measurement. The research results show that crustal stress of tunnel axis varies with embedded depth and topographic features; and the section K42 is of very high stress. The results provide a scientific foundation for analyzing excavation

support and stability of tunnel.