Spiral piles are a type of foundation for small structures made of twisted steel strip. Spiral piles provide high axial resistance and can be easily removed when no longer needed. The authors have focused their research on coupled pile structures that can convert the higher axial resistance of spiral piles into horizontal resistance. In this study, a coupled foundation structure using cast iron spiral piles and steel pipe piles, which have excellent shape flexibility and economic efficiency, was designed as a practical foundation for vehicle protection fences. In order to clarify its horizontal resistance characteristics, field pull-out tests and horizontal load tests were conducted using test soil and a full-scale test specimen. As a result, the onset characteristics of the pull-out resistance of spiral single piles and the horizontal resistance of the coupled foundation were analyzed, and a practical method of calculating the horizontal resistance in relation to the mechanical properties of the soil was presented.