Study on the Mechanical Performance of Prefabricated Helical Anchor Foundations with Mechanical Connections Under Wind Loads
Bingxiu Xu, Xiao Yang, Huan Zhang, Huichao Ma, Dongyu Tian, Xinpeng Li, Wenming WangObjective:
To address the long construction periods and extensive wet operations of conventional transmission tower foundations, this study proposes a prefabricated helical anchor foundation with mechanical connections and evaluates its mechanical performance and structural safety under critical wind loading.
Methods:
A two-stage finite element analysis was implemented in ABAQUS. First, a three-towerfour- span 220 kV transmission tower-line system model was established to extract the time history of tower-base reactions under wind loading. Subsequently, comparative simulations were conducted between the proposed prefabricated foundation and a conventional cast-in-place foundation under uplift and compressive loads.
Results:
The prefabricated foundation exhibited load-transfer paths and dynamic responses consistent with the cast-in-place baseline. Under uplift loading, the maximum displacement of the prefabricated foundation decreased by 5.39%, 11.68%, and 24.02% at wind directions of 0°, 45°, and 90°, respectively, showing superior pullout and crack resistance. Under compressive loading, its maximum downward displacement decreased by 9.08%, 15.78%, and 15.82%, respectively, with a peak local concrete compressive stress of only 2.19 MPa, well below the capacity of C30 concrete.
Discussion:
The mechanical connection promotes a more rational internal force redistribution among the foundation cap, anchorage components, and surrounding soil, effectively alleviating localized stress and deformation concentrations.
Conclusion:
The proposed prefabricated helical anchor foundation ensures satisfactory structural safety while offering substantial engineering advantages, including factory prefabrication, rapid onsite assembly, and shortened construction time, demonstrating high potential for practical applications.