## 1 Introduction  
As construction technology continues to advance, precast concrete piles have become prevalent in the construction industry due to their wide application range, ease of quality control during pile formation, and convenient construction [1, 2, 3]. However, during the process of pile driving, conventional precast piles often generate a crowding effect on the surrounding soil, which can have significant implications for nearby structures [4, 5, 6, 7]. Static drilling and rooting pre-tensioned prestressed concrete bamboo piles, known as PHDC piles, are an innovative environmentally friendly pile solution that utilizes hydraulic soil compaction around bamboo-reinforced pile bodies [8]. However, due to fabrication and transportation constraints, bamboo piles require joints for assembly. The load-bearing capacity of these piles is intricately linked to the performance of these joints. Recent domestic and international research on the bearing capacity of pile connections has primarily focused on two main connection methods: welding and mechanical connections. [PERSON] et al. [9] conducted bending tests on welded joints of prestressed concrete hollow square piles and concluded that the welded joints met the specification requirements in terms of test values. Additionally, they found that the quality of the weld joints significantly impacts the load-bearing capacity of the joints. [PERSON] et al. [10, 11] conducted a comparative study on the durability of traditional welded joints and snap joints. Their research revealed that snap joints exhibit better performance under corrosion conditions compared to welded joints. Specifically, they observed that while snap joints maintain their strength relatively well in corrosive environments, the strength of welded joints decreases significantly due to corrosion. In some cases, the corrosion may lead to severe deterioration or even detachment of the welds. The literature highlights that while welded joints can meet the requirements for pile connection bearing capacity, they often exhibit poor durability performance, and the quality of welds may be inconsistent. Consequently, numerous domestic and international researchers have proposed various new types of connections to address these shortcomings. [PERSON] et al. [12] introduced a snap-type quick coupling for endplate-enhanced prestressed concrete pipe piles without endplates. Their study demonstrated that this quick coupling offers rapid pile connection, is unaffected by human and weather factors, and possesses good corrosion resistance and durability. [PERSON] et al. [13] proposed a novel type of mechanical coupling joints and conducted tensile, flexural, and compression tests on them. The results confirmed the effectiveness of these coupling joints. [PERSON] [14] introduced an embedded anchorage connection and conducted both full-scale tests and numerical simulations to assess its mechanical properties. The results of these tests and simulations confirmed that the joint specimens met the specified requirements, indicating the effectiveness and suitability of the embedded anchorage connection for its intended purpose. [PERSON] et al. [15; 16; 17] designed a new type of connection joint for composite reinforced concrete precast square piles. Flexural performance tests on full-size specimens revealed that the ultimate flexural capacity of this joint exceeds the calculated value of the pile specification formula, indicating excellent load-carrying capacity and deformation performance. [PERSON] et al. [18; 19] conducted full-scale tests and numerical simulations on specimens of prestressed concrete square pile joints connected by elastic cards. Their findings confirmed that the bearing capacity meets design requirements and exhibited good deformation ductility. Mechanical joints offer numerous advantages over welded joints, yet traditional welding remains the prevalent connection method in actual construction.