## 1 Introduction  
Many domestic and international studies have been performed on the behavior of piles exposed to vertical loads and considerable research has been actively conducted on the behavior of piles subjected to lateral loads. Piles that are exposed to lateral loads, due to actions such as wind, will experience greater moments than piles exposed to vertical loads. Because of this, it is necessary to study the behavior related to the lateral loading of piles. [PERSON] et al. [PERSON] et al. (2019) used numerical analysis and performed cyclic loading of a monopile in 102-104 cycles to study the long-term behavior of the soil. [PERSON] and [PERSON] [PERSON] and [PERSON] (2018) performed static and cyclic loading tests on monopiles on a small scale, and these were numerically analyzed and compared. [PERSON] et al. (2018) used a Strain Wedge Model (SWM) to perform 1-10\({}^{5}\) cycles of lateral loading on a monopile, and they also studied the pile head displacement and initial stiffness, according to the increase in cycles. [PERSON] (2018) performed one-way cyclic loading tests on a pile with a diameter of 60 mm in sand with a relative density of 40% and 60%. Various loads were used, and 10,000 load cycles were performed. [PERSON] et al. [PERSON] et al. (2018) performed cyclic loading tests using a pile with a diameter of 60 mm, loaded for 46,000 cycles at relative densities of 78% and 87%. [PERSON] and [PERSON] [PERSON] and [PERSON] (2018) performed cyclic loading tests on a steel pipe pile with a diameter of 324 mm in full scale to find the so-called p-y curve. The p-y curve is used to analyze the pile lateral support behavior. Here, p is the soil resistance, and y is the displacement. [PERSON] and [PERSON] [PERSON] and [PERSON] (2018) examined the effect of changesin the pile diameter on the p-y curve and found that the effect was slight. The p-y curves which are commonly used now were presented by API [8] and calculated from experiment values obtained by [PERSON] [9] in clay and from static and cyclic experiments by [PERSON] et al. [10] in sandy soil. In addition to this, there are other types of p-y curves, such as the Reese [11] p-y curve and the NCHRP [12] p-y curve. However, because these were formulated using results obtained from experiments on piles with diameters smaller than 1 m, they have a limited ability to predict the support behavior of large-scale monopies that are mainly used as wind tower power support structures. In miniature tests in a 1 g gravity field, only the prototype's shape has a scale relationship. Therefore, the tests have a disadvantage, in that the stress-strain behavior caused by the soil's actual weight is different from the ground. To compensate for this, several studies have been conducted using centrifuge models. [PERSON] and [PERSON] [13] studied the behavior of a pile with a diameter of 6 m. Their results showed that both the initial modulus of subgrade reaction and the ultimate soil resistance were smaller than in the existing p-y method. [PERSON] et al. [14] used centrifuge model tests to analyze the effect of secant stiffness on cyclic lateral load. [PERSON] et al. [15] used a model aluminum pile in centrifuge model tests in dry sand to compare the static p-y curve with the API static p-y curve, and they proposed a dynamic p-y curve. However, the dynamic p-y curve was found for an earthquake load, caused by a vibrating table. As such, it may not be useful in designs regarding the cyclic load caused by wind or waves acting on the top of a pile. Despite these numerous studies, there are few consistent results regarding piles exposed to a lateral load. Additionally, these loads are difficult to apply to large-caliber piles that have large diameters. This study uses centrifuge model tests to analyze the lateral behavior of a monopile that is embedded in dry sand. When the scale ratio was used, the monopiles had a diameter of 3.3 m, and a cyclic load was applied to the pile head.