# Research on Lateral Bearing Behavior of Spliced Helical Piles with the SPH Method
## 1 Introduction  
A helical pile can be guided to sink to a predetermined depth by transmitting torque through the blades to spin into the soil. Compared to the traditional hammering and static-pressing methods, the spliced helical pile has significant advantages in the form of minor damage to the ground surface, weak vibration, and low noise during the pile-installation process. After the installation, the helical piles are loaded immediately and can be used for dam closure, rope hooking, and the foundations for PV-support brackets [1, 2]. In order to accurately research the performance of the piles under lateral load, many scholars have developed pile model testing devices for the X-ray-CT method. In the study by [PERSON] [3], X-ray-CT methods were used as a non-destructive technique to quantify the load distribution mechanism. [PERSON] [4] conducted model tests and X-ray-computed tomography analysis to study permeable concrete pile (PCP) blockages. [PERSON] [5] accurately observed the damage pattern of sandy soils under pile lateral loads by performing model loading tests with X-ray-CT scanning. The CT methods are limited to model tests and are expensive. The methods are not always available in most laboratories. Alternatively, there was the use of transparent soil technology visualization to measure the horizontal stressed-soil displacement on the side of the pile, with a non-intrusive capture by particle imagery, overcoming the barriers to measurement caused by the opacity of the natural soil [6, 7, 8, 9, 10]. However, this method makes it difficult to simulate the working of full-size piles of soil. Numerical simulations can be used to obtain results that are similar to the actual ones [11, 12, 13], and the analysis of the soil model uses a solid mesh-cell approach, where the meshes themselves are already co-noded with each other, which can lead to variousdifficulties in dealing with free surfaces, deformable boundaries, moving interfaces, large deformations, and crack extensions. In addition, the generation of high-quality meshes is time-consuming for problems involving complex geometry. [PERSON] [14] simulated high-pressure melting, [PERSON] [15] modeled a large landslide, [PERSON] [16; 17] achieved excellent results in an underwater explosion, and [PERSON] [18] and [PERSON] [19] used smooth particle hydrodynamics (SPH) methods for the simulation of liquid-swaving flows during shipment. As no meshes are used, the connectivity between the particles is generated as part of the calculation and varies over time. SPH is an adequate replacement for CT image capture and entire 3D displacement-measurement systems for the 3D displacement fields of the soil around the laterally loaded piles in transparent and coastal sandy soils. The soil model of pile-soil interaction uses the SPH approach to simulate the micromechanical behavior of the soil at the minor particle level, including the contact stresses and displacements, to explain phenomena that cannot be directly observed and experimentally discussed. Because of its Lagrangian character, a time history can be obtained, and the free surfaces, material interfaces, and moving boundaries can be easily tracked during simulation by properly deploying the particles at specific locations during the initial phase. [PERSON] [20] used Ansys to simulate the deformation of welded piles. [PERSON] [21] analyzed the resistance of the sunken pile according to the principle of pile-soil action and the theory of mechanical equilibrium; then, specific measures were proposed to appropriately reduce the outer diameter of the hollow cylinder, while keeping the outer diameter of the base of the cone unchanged and appropriately reducing the length of the helical blade. [PERSON] [22] slotted the pile at the tip and reduced the sinking time by 8.85%. However, the monolithic helical piles are only suitable for specific applications where spliced helical piles are an ideal structure to permit them to continue to operate under different working conditions.