# The Mechanical Properties of Reinforced Concrete Columns with Longitudinal Pre-Embedded Holes
## 1 Introduction
[11] conducted experiments on reinforced concrete columns with drilled circular holes under compression, finding that the presence of holes alters the stress-strain state, leading to a reduction in load-bearing capacity, which further decreases with larger hole diameters. [PERSON] et al. [12] used finite element software to explore the influence of different hole shapes on the load-bearing capacity of concrete columns with openings, concluding that circular holes exhibit greater stiffness compared to square holes. [PERSON] et al. [13] studied the effects of load eccentricity on the load-bearing capacity of columns with transverse holes under axial loading and uniaxial bending. They found that when the longitudinal axis of the hole is in the plane of the eccentric bending moment, the column's behavior is more pronounced compared to when the longitudinal axis of hole is perpendicular to the plane. [PERSON] et al. [14] investigated the influence of factors such as the main reinforcement ratio and stirrup distance on the load-bearing capacity of reinforced concrete columns with openings. Their experimental results showed that the reinforcement ratio and stirrup distance have minimal impact on the load-bearing capacity. [PERSON] [15] used finite element methods to analyze the influence of drilled transverse holes on the mechanical performance of reinforced concrete columns under axial pressure and proposed repair methods for mitigating the influence of the holes. The study found that repaired columns exhibited a significant recovery in performance. [PERSON] [16] employed finite element methods to study the effects of various parameters of transverse holes on the load-bearing capacity of columns and proposed multiple strengthening solutions to enhance the performance of columns with openings. The study identified that installing CFRP sleeves and steel sleeves inside the holes were effective strengthening methods. [PERSON] et al. [17] used experimental and numerical simulation methods to study the influence of transverse circular holes on the load-bearing capacity of reinforced concrete columns, finding that increasing the column size is the most effective way to accommodate transverse circular holes. [PERSON] et al. [18] conducted an in-depth study on parameters such as the opening ratio, opening location, concrete strength, and loading eccentricity, systematically analyzing their effects on the strength of reinforced concrete columns with transverse openings. [PERSON] et al. [19] investigated the influence of holes on the triaxial mechanical properties of high-performance concrete, revealing that different hole sizes lead to varying stress concentrations under different confining pressures, resulting in differences in strength and deformation characteristics. [PERSON] [20] studied the influence of the opening ratio in the core region of prefabricated columns under compression, concluding that a higher opening ratio significantly weakens the specimens and reduces the load-bearing capacity of the columns. [PERSON] et al. [21] explored the effects of key parameters such as concrete strength, opening ratio, and hole shape on the ductility index and ultimate load-bearing capacity of partially encased concrete (PEC) columns with web openings under axial loading. Their findings revealed that the opening ratio has a significant impact on the load-bearing capacity, while the hole shape has a relatively minor influence. Additionally, longitudinal pre-embedded holes traversing the core region of beam-column joints may reduce their load-bearing capacity. [PERSON] et al. [22] investigated the post-earthquake building inventory in central Adyaman and observed that reinforced concrete structures with hollow block floor systems instead of beam-slab systems frequently exhibited large-scale collapses or severe damage. These findings demonstrate that beam-column joints are critical to structural stability and require protective measures. [PERSON] et al.