为了提高普通钢管混凝土墩柱的承载性能, 满足井下巷道高度2.5~3.0 m特定条件巷旁支护体的需求, 提出了一种内配型钢钢管混凝土墩柱支护体, 设计了满足井下巷道尺寸的特定长径比的钢管混凝土墩柱参数。对普通钢管与内配型钢钢管混凝土短柱力学性能进行试验对比, 并对钢管混凝土长柱轴压力学性能进行研究, 结果表明: 内配型钢钢管混凝土墩柱局部鼓曲现象及核心混凝土的破坏程度较轻, 横向和纵向变形均小于普通钢管混凝土墩柱, 在受力时破坏行为较为缓慢, 延性性能较好; 内配型钢钢管混凝土墩柱的极限承载力比普通钢管混凝土墩柱高约500 kN; 随着钢管管径的增加, 钢管混凝土长柱的弹性极限应变为0.1%~0.6%, 塑性极限应变为2.0%~6.7%, 钢管混凝土长柱的承载能力受长径比的影响而显著降低, 其破坏形式为明显的屈曲变形。研究结果可为钢管混凝土墩柱的结构优化和力学性能提升提供参考。

To enhance the bearing capacity of conventional concrete-filled steel tubular columns and meet the requirements of roadside support structures in underground roadways with heights ranging from 2.5 to 3.0 meters, an internally reinforced steel concrete-filled steel tubular pier column was proposed. Specific design parameters for concrete-filled steel tubular columns with appropriate length-to-diameter ratios were developed to suit the conditions of underground roadways. Comparative experiments were conducted to evaluate the mechanical properties of conventional and internally reinforced concrete-filled steel tubular short columns, and the axial compression performance of concrete-filled steel tubular long columns was also studied. The results indicate that the internally reinforced concrete-filled steel tubular pier columns exhibit reduced local buckling and core concrete damage compared to conventional concrete-filled steel tubular pier columns. These columns demonstrate smaller lateral and longitudinal deformations, slower failure progression, and superior ductility. Additionally, the ultimate bearing capacity of the internally reinforced concrete-filled steel tubular pier column is 500 kN higher than that of its conventional counterpart. For concrete-filled steel tubular long columns, the elastic limit strain ranges from 0.1% to 0.6%, while the plastic limit strain ranges from 2.0% to 6.7%. However, the bearing capacity of concrete-filled steel tubular long columns decreases significantly with an increasing length-to-diameter ratio, and their failure mode is characterized by pronounced buckling deformation. These findings provide valuable insights for optimizing the structural design and improving the mechanical performance of concrete-filled steel tubular pier columns.