Introduction: With the growing demand for wind power generation, hybrid tower wind turbines are increasingly being deployed in mountainous regions with abundant wind energy resources. To improve the adaptability and structural safety of hybrid tower foundations under complex geological conditions, such as those in mountainous regions, this study proposes the use of a rock bolt composite foundation. In this configuration, rock bolts are installed around the hybrid tower foundation, forming a composite system in which the foundation and the bolts jointly resist external loads. Methods: To evaluate the effectiveness of the addition of rock bolts and to investigate the mechanical performance of the composite foundation. Finite element models of both the hybrid tower foundation and the rock bolt composite foundation were developed using ABAQUS. These models were subjected to identical design loads, and their structural responses—including concrete stress, foundation displacement, and reinforcement stress—were compared and analyzed. Based on the results of the response analysis, an optimized design was proposed to further reduce the foundation dimensions and overall material consumption, thereby enhancing both structural performance and cost-efficiency. Results: The results indicate that, under the condition of constant total rock bolt usage, a slight improvement in the mechanical performance of the rock bolt composite foundation is observed as the diameter of the rock bolts decreases; however, the enhancement is not substantial. After the installation of additional rock bolts, the mechanical performance of the foundation was significantly improved. Discussion: Specifically, the tensile stress in the concrete decreased by 27.81%, the compressive stress decreased by 11.88%, the foundation displacement was reduced by 35.39%, and the reinforcement stress was reduced by 42.74%. After reducing the dimensions of the hybrid tower foundation and incorporating additional rock bolts, the mechanical performance of the foundation was further enhanced, while construction costs were effectively reduced. Conclusion: The rock bolt composite foundation demonstrates significant advantages not only in structural mechanical performance but also in reducing construction costs and optimizing resource allocation, thereby showing strong potential for engineering applications—particularly in mountainous regions with complex terrain and limited accessibility for material transportation. This study may also provide a valuable reference for the patent-oriented design and further innovation of hybrid tower foundations in such environments.
Zhang et al. (Tue,) studied this question.