Previous studies have analyzed the damage of tunnels and slopes as a single entity, ignoring the interaction effect between the tunnels and slopes, which will have an impact on the accuracy of the damage mechanism and the safety of the treatment measures. In this paper, three types of simulation models are established—the natural state, after tunnel excavation, and after reinforcement measures—considering a case study of an underpass landslide tunnel in southwest China. Based on the theory of underpass landslide tunnels and the strength reduction method, the interaction damage mechanism of this underpass landslide tunnel is revealed, and a reasonable treatment plan is proposed. The analysis results show the following: there is an obvious interaction effect between the tunnel collapse and the slope instability; a large number of mudstones common in the surrounding rock of the tunnel have rheological properties, which amplify the influence of the interaction effect of the tunnel through the landslide; and the proposed comprehensive treatment measures of “rescue inside the tunnel cave + tunnel slope treatment” have strong pertinence and effectiveness, and they fundamentally address the tunnel collapse and the slope instability of the tunnel.

Recycling reclaimed asphalt pavement (RAP) for asphalt pavement construction is of interest due to its potential to mitigate environmental impact and resource consumption; however, the addition of RAP limits the induction heating behavior of asphalt mixtures, hindering the further application of RAP in sustainable and functional asphalt pavement. This study prepared recycled asphalt mixtures with high contents of steel slag aggregate and RAP, and optimized the rejuvenator dosage and composition design to investigate the induction heating rate. The effect of the steel fiber content, heating time, and heating distance on the induction capacity were verified for the recycled asphalt mixture. Moreover, the cooling curves of the recycled asphalt mixture were explored using a constant temperature chamber and infrared camera. The results showed that 6 wt% of rejuvenator in aged asphalt could evidently restore the physical properties and surface morphology, the highest heating rate of 1.204 °C/s could be reached with 2 wt% of steel fiber content, and the effective intervals of heating time and heating distance were set as 60–120 s and 10–20 mm, respectively. This study could be a significant reference in promoting solid waste recycling and sustainable asphalt pavement construction.