The objective of this study is to calibrate continuous surface cap model (CSCM) for ultra-high-performance concrete (UHPC), and then to investigate the structural behavior of UHPC filled thin-walled steel tubular (UHPCFTWST) column against monotonic lateral loading via numerical simulation of nonlinear pushover analysis. The parameters of CSCM model for UHPC were derived via fitting experimental data of a series of tests on UHPC under uniaxial/triaxial states. Subsequently, a detailed 3D FE (finite element) model of UHPCFTWST column against monotonic lateral loading was developed and validated. After that, the effect of main design parameters, including steel ratio, steel grade, axial compression ratio, dosage of steel fiber, and bonding strength, on the structural behavior of UHPCFTWST column against monotonic lateral loading was investigated via a parametric study based on the FE model. Eventually, the axial pressure-moment (P-M) interaction diagram of a specified UHPCFTWST column was derived to illustrate the sectional response. Comparisons of the lateral behavior of UHPCFTWST column with that of normal strength concrete (NSC) filled steel tubular (NSCFST) column were also made for better illustrations. It indicates that the lateral load capacity and ductility were both improved with the increase of steel ratio, whereas the increase of steel grade improved the lateral load capacity but reduced the ductility owing to the increase of yield drift ratio. Moreover, the increase of axial compression ratio improved the lateral load capacity but significantly degraded the ductility. Although the increase of the dosage of steel fiber improved the lateral load capacity and ductility, but a suitable volume ratio should be specified in consideration of the cost. The comparisons with NSCFST column indicated the advantage and potential of UHPC application to concrete filled steel tubular (CFST) column with a thinner steel tube and a higher grade of steel. The P-M interaction diagram of UHPCFTWST column exceeds that of NSCFST column by a large extent, which indicates a greater safety redundancy.

这项研究的目的是要校准超高性能混凝土（UHPC）的连续表面盖模型（CSCM），然后研究UHPC填充薄壁钢管（UHPCFTWST）柱通过单向横向荷载对结构的影响。非线性推覆分析的数值模拟。UHPC的CSCM模型的参数是通过在单轴/三轴状态下对UHPC进行的一系列测试的拟合实验数据得出的。随后，开发并验证了针对单调侧向载荷的UHPCFTWST柱的详细3D FE（有限元）模型。之后，主要设计参数的影响，包括钢的比例，钢的等级，轴向压缩比，钢纤维的用量以及粘结强度，通过基于有限元模型的参数研究，研究了UHPCFTWST柱对单调侧向荷载的结构性能。最终，得出了指定的UHPCFTWST柱的轴向压力-力矩（PM）相互作用图，以说明截面响应。为了更好地说明，还对UHPCFTWST柱与普通强度混凝土（NSC）填充钢管（NSCFST）柱的侧向性能进行了比较。结果表明，随着钢种比的增加，侧向承载能力和延性均得到提高，而钢种的增加则提高了侧向承载能力，但由于屈服比的增加而降低了延性。此外，轴向压缩比的增加改善了侧向承载能力，但显着降低了延展性。尽管增加钢纤维的用量可以改善侧向承载能力和延展性，但应考虑成本确定合适的体积比。与NSCFST柱的比较表明，UHPC在钢管更细，等级更高的钢管混凝土（CFST）柱中的优势和潜力。UHPCFTWST列的PM交互图大大超过了NSCFST列的PM交互图，这表明更大的安全冗余。与NSCFST柱的比较表明，UHPC在钢管更细，等级更高的钢管混凝土（CFST）柱中的优势和潜力。UHPCFTWST列的PM交互图大大超过了NSCFST列的PM交互图，这表明更大的安全冗余。与NSCFST柱的比较表明，UHPC在钢管更细，等级更高的钢管混凝土（CFST）柱中的优势和潜力。UHPCFTWST列的PM交互图大大超过了NSCFST列的PM交互图，这表明更大的安全冗余。