Abstract:Fuxi twin tunnel in Tangkou—Tunxi section of Tongling—Huangshan Expressway is eccentric compressed with the length of 623 m. Weathered meta sandstone at the portal is loosely structured and unstable. The portal is apparently eccentric with the left side buried deeper than the right side. Three pilot tunnel method has been applied for tunneling. During the construction,site monitoring and measurement have been conducted for various cross sections of the three pilot tunnels and the main tunnel. Data have been studied and analyzed. Deformation of the surrounding rocks and stress of the supporting structures have been noted. Monitoring result shows that,after the heading-through of the central pilot tunnel,construction is organized firstly on the pilot tunnel of the shallow- buried side. It is envisaged that the deformation of the surrounding rocks of the shallow buried section is greater than that of the deep buried one. During the construction of the main tunnel,arch crown subsidence at the deep buried section is greater than that of the shallow buried section. The horizontal convergence at the deep buried section tends to be expansive while that at the shallow buried one shrinking,which causes the movement of the mid-board towards the later section. Initial supporting and secondary lining also envisages the greater pressure of the surrounding rocks as well as the greater internal stresses of the concrete at the deep buried section. As it has the tendency of moving towards the shallow buried section during the integral lining,the steel shotcrete at the section bears greater stress. This analysis offers some technical assistance to the construction of Fuxi eccentric compressed tunnel as well as some references for the design,construction and research of the similar engineering.