【摘要】 波形钢腹板(corrugated steel web, CSW)-钢底板组合梁结构用钢底板替换普通混凝土底板，并在负弯矩区段腹板和底板内布置内衬混凝土以提高其抗剪、稳定、抗弯承载能力，可进一步提高传统波形钢腹板组合梁桥轻型化水平，并解决其受拉区普通混凝土抗裂性能差的问题。为研究该结构负弯矩区段弯曲性能、抗裂性能与钢混应变协调情况，依托一座主跨200 m的CSW-钢底板组合梁桥，设计并制作一片1∶6的大比例负弯矩区缩尺模型试验梁，通过一种自平衡加载装置完成全过程静力加载试验，获得试验梁典型截面应变、开裂荷载、裂缝发展规律等关键结构响应结果。根据截面应力分布提出CSW-钢底板组合梁开裂弯矩的计算方法，依据截面平衡条件提出结构极限抗弯承载力的简化计算公式，根据相对界限受压区高度评估截面布置的合理性。结果表明：缩尺模型简化计算方法能够有效反映实际结构受力特征，CSW-钢底板组合梁开裂荷载为1.4倍基本组合荷载，结构具有较强的抗裂性能，开裂弯矩计算结果与试验梁吻合良好；极限抗弯承载力计算公式结果可靠，结构极限抗弯承载力为开裂荷载的1.71倍，抗弯性能优异；预应力度是截面抗裂性能和极限抗弯承载力的关键因素，结构钢混协同受力情况良好，布置内衬混凝土可有效改善结构负弯矩区段受力性能。更多还原

【Abstract】 The corrugated steel web(CSW)-steel bottom plate composite girder replaces conventional concrete bottom slabs with steel plates and incorporates concrete linings in the webs and bottom plates within negative moment regions to enhance shear resistance, stability, and flexural capacity. This innovation further advances the lightweight design of traditional CSW composite girders while addressing the poor crack resistance of concrete in tension zones. To investigate the flexural behavior, crack resistance, and steel-concrete strain coordination in negative moment regions, a 1∶6 large-scale scaled model of a 200 m main-span CSW-steel bottom plate composite girder bridge was designed and fabricated. A self-balancing loading system was employed to conduct full-range static tests, capturing critical structural responses including strain distribution, cracking load, and crack propagation. A calculation method for cracking moments was proposed based on sectional stress distribution. A simplified formula for ultimate flexural capacity was derived using sectional equilibrium conditions. The rationality of the cross-sectional layout was evaluated by analyzing the relative depth of the compression zone. Conclusions are drawn as follows. The scaled model effectively reflects the mechanical behavior of the prototype structure, with a cracking load of 1.4 times the basic combination load, confirming superior crack resistance. Calculated cracking moments align well with experimental values. The simplified formula reliably predicts ultimate flexural capacity, achieving 1.71 times the cracking load, indicating excellent performance. Prestress level is critical to crack resistance and ultimate capacity, while concrete linings significantly improve mechanical behavior in negative moment regions through effective steel-concrete synergy.更多还原