Abstract:

The application of ground penetrating radar to the detection of voids behind Wangshiling Tunnel lining and the core drilling results show that the ground penetrating radar is feasible and reliable. A 3D fast Lagrangian finite difference analysis model of twinarch tunnel is established based on insitu testing data, so as to analyze the influence of voids behind tunnel lining on tunnel structure. The numerically analytical results show that: 1) The local concentrated tensile stress would be resulted due to the voids above crown top and behind arch shoulders and sidewall. 2) The concentration degree of tensile stress is affected by locations and sizes of voids. Under the condition of vertical ground stress, the voids behind arch shoulders are the most dangerous and can induce large stress concentration above arch shoulders. As a result, more attention should be paid to detection of voids behind arch shoulders.

Key words: highway tunnel, ground penetrating radar, void behind lining, core drilling, numerical analysis