Abstract:In order to determine the variation law of the anti-slide performance of the pavement under the condition of snow at the entrance and exit of the tunnel, the pendulum value of the 25 m interval between the entrance and exit of the Hengshan Tunnel and the Baofengling Tunnel during the natural snowfall process is measured by pendulum instrument. And the pavement temperature of the two tunnels at an interval of 10 m is collected by infrared thermometer when the pavement is dry in sunny days. The analysis results show that the tunnel entrance and exit show three states of melted snow pavement, floating snow pavement and compacted snow pavement. The pendulum values of the three pavements decrease sequentially. The pendulum value fluctuation range of the tunnel entrance exceeds the tunnel exit. The pendulum value fluctuation range of tunnel entrance is 50 m inside the entrance to 170 m outside the entrance. The pendulum value fluctuation range of tunnel exit is 25m from the tunnel exit to the outside of the exit. The pavement temperature in the tunnel is lower than that of the subgrade section, and there is an obvious temperature reduction shock on the pavement at the entrance and exit of the tunnel. It can be seen from this that the compaction snow pavement of the tunnel entrance is mainly caused by the temperature reduction at the entrance. There is no significant relationship between the change of tunnel exit pendulum value and pavement temperature. The study can provide the technical support for the prevention and early warning of tunnel entrance and exit accidents under snowfall conditions.
