## 1 Introduction
On the premise of ensuring the project quality, it can greatly speed up the construction progress, improve the construction production efficiency, and be conducive to environmental protection. At the same time, the prefabrication and assembly technology of bridge structure has the characteristics of high efficiency, safety, high quality, speed, and environmental protection, which has become the development trend of bridge construction [29]. At the same time, scholars at home and abroad have also carried out a lot of research work on prefabricated bridge structures. In 2004, [PERSON] et al. proposed a segmental assembled pier system and designed and manufactured seven specimens for the quasi-static test, and test results showed that the pier in this system had good ductility, strong energy consumption, small residual displacement, and improved ultimate load [30]. [PERSON] et al. conducted pseudo-static and pseudo-dynamic tests through the 1:3 scale models and obtained the self-resetting performance and seismic performance of the unbonded post tensioned prestressed segmental pier with low carbon steel viscous damper were good [31]. [PERSON] et al. put forward several methods to improve the energy dissipation capacity of the structure for the prestressed tensioned precast segmental piers widely used all over the world [32]. [PERSON] et al. proposed a form of a prefabricated cylindrical section with hollows, to improve the seismic performance of the column [33]. Through the numerical study of the assembled pier of Donghai Bridge, [PERSON] et al. discussed the influence of prestress on the seismic performance of the pier and put forward a method that can not only meet the operation requirements but also enhance the seismic performance [34]. Moreover, the soil field also has a significant influence on the internal force and deformation of piles. [PERSON] et al. studied the effects of scouring and the layered soil on the dynamic response of the single pile by numerical calculation and parameter analysis [35]. [PERSON] et al. investigated the influence of pile spacing on the dynamic behavior of pile groups by performing experiments on pile foundations embedded in a two-layered soil profile, and considered soil-pile-structure interaction effects [36]. The application of prefabricated bridges is of great significance to the development of building industrialization. However, the substructure of a conventional prefabricated bridge needs to cast a bearing platform between pier and column. This method will not only occupy the existing road, but also affect the rapid construction, and cannot give full play to the advantages of prefabricated bridge construction. Given the engineering characteristics that most of the pile foundations in the bridge design of this project are end-bearing piles, in which the pile foundation is not deep and the pile column is not high, the assembly process by using \"pile-column integration\" has been proposed in this study. Aiming at the reconstruction and expansion project of the Qinzhou-Beihai section of the Lanzhou-Haikou (i.e., Lanhai) expressway, the test site with representative geological conditions was firstly selected. The pile column structure of the bridge can be completed by prefabricated pile foundation, pier, and capping beam based on the integral assembly installation method. The vertical compressive static load test, horizontal static load test, and reliability test of pile-column connection were introduced in detail to analyze whether the bearing capacity and connection effect of pile-column can meet the requirements.