Abstract:
The Tunnel-Soil-Pile Interaction (TSPI) analysis is a widely used research to check the performance of tunnels under seismic excitations. The utilization of tire-derived aggregates (TDA) is an entirely novel approach to tunneling. This research includes a study on an existing TSPI model with different arrangements of TDA in the sand deposit. The TSPI model, along with the TDA, has undergone a variety of seismic and sinusoidal waves. The dynamic loadings are the Kobe earthquake and the Loma Prieta earthquake, with PGA values of 0.05g, 0.10g, 0.15g, and 0.20g, and the sinusoidal form with frequencies of 1 Hz, 3 Hz, 5 Hz, and 7 Hz for the PGA of 0.05g. Three different TDA arrangements, i.e., layered TDA model, randomly mixed TDA model, and TDA around the tunnel models, were used to check the response of the tunnel. The strain, acceleration, and displacement of different parts of the tunnel, soil, and pile were measured. In the case of the top and bottom strain of the tunnel, for all the seismic waves and sinusoidal waves, the most effective TDA model was the layered TDA model. This model reduced approximately 80-90% of the tunnel top strain and 30-40% of the tunnel bottom strain than the other two models. In the case of the vertical displacement of the tunnel, the TDA around the tunnel model showed a 40-70% reduction than the other two models for all the seismic and sinusoidal waves. In the case of the lateral displacement of the tunnel, the random TDA model showed an 85% reduction for the Kobe earthquake, and the TDA around the tunnel showed a 13% reduction for the Loma Prieta earthquake. On the contrary, the random TDA model showed an increase in the lateral displacement for sinusoidal waves than the other two models. For the Kobe earthquake, the pile cap and tunnel crown acceleration of TDA around the tunnel and layered TDA model was higher than the base acceleration. Only the pile cap acceleration for the random TDA model showed lower acceleration. For the Loma Prieta earthquake, all the models showed a decrease in the acceleration of the pile cap and tunnel crown. The overall performance of the TDA around the tunnel was the most stable. In the case of the sinusoidal wave, the TDA around the tunnel showed a decrease in the pile cap and tunnel crown acceleration. Usage of TDA in TSPI can reduce the effect of seismic and sinusoidal waves, but not all the models are similarly effective. It is prudent to use a combination of models, which can result in a better reduction in the effect of seismic waves on TSPI.