## 5 Conclusions  
This research investigates the performance of a novel prefabricated cantilever structure (PCS) roadbed subjected to various traffic load distributions, incorporating laboratory and field tests along with numerical simulations, all based on an actual mountainous road construction case. The mechanical behavior of the structure was examined under the following three extreme vehicle loading conditions: (1) external eccentric load, (2) internal eccentric load, and (3) full load. Based on the findings, the structure underwent optimization by incorporating prestressed rebars into the cantilever beams. The key conclusions are as follows:  
1. The prefabricated cantilever structure model presented in this study effectively replicates the real-world stress and failure characteristics of the structure. In the scaled model, the load-bearing capacity curves derived from both simulations and laboratory experiments demonstrate a high degree of consistency. For the full-scale model, comparisons between simulated and actual stresses on the cantilever beams during paving further corroborate the model's accuracy, verifying its robustness and reliability. 2. Under varying vehicular loads, the connection between the cantilever beam and the column is identified as a critical weak point, characterized by significant stress concentration. While the reinforcements in this region endure high stress, the tensile strength of the concrete is relatively low. However, once cracking occurs in the concrete, the tensile stress will be borne by the steel bars, and failure could result from either the yielding of the steel bars or the failure of the concrete compression surface, potentially leading to the collapse of the entire structure. 3. The incorporation of prestressed rebars in the tension zone of the cantilever beams optimizes the internal stress distribution, alleviating stress concentration, and leading to a more uniform overall stress distribution, thus improving the structural performance. Positioning prestressed rebars at both the inner and outer top surfaces of the cantilever beams significantly enhances stress distribution under both external and internal eccentric loads. Additionally, adding prestressed rebars at the bottom of the inner cantilever beam further refines stress distribution under full loading conditions. Figure 20: Finite element calculation results. 4. Incorporating prestressed rebars into the cantilever beams improves the structure's overall stiffness, load-bearing capacity, and ductility, while delaying the initiation of structural damage. Simulations of the optimized structure under ultimate load conditions show that the inclusion of prestressed rebars, especially at the top inner and outer cantilever beam surfaces, notably enhances the initial slope and peak load of the displacement-load curve, along with a reduced descending slope. The damage distribution analysis indicates that adding prestressed rebars, particularly at the top inner and outer sides, significantly mitigates damage at critical beam-column connections, improving stress distribution and preventing rapid damage propagation. This study presents a reliable approach for assessing and optimizing the performance of innovative prefabricated cantilever structures, significantly advancing their practical engineering application. The proposed structure offers a cost-effective and reliable solution for highway construction in mountainous regions with challenging terrain. By simplifying the construction process and reducing costs, this structure provides a practical alternative for engineers facing complex topographical constraints. However, certain limitations exist in the current research. For instance, variations in material properties and uncertainties in boundary conditions were not considered. Additionally, the long-term effects of environmental factors on structural performance were not addressed.