【摘要】 钢箱-混凝土组合连续梁负弯矩区混凝土的开裂问题影响了这类组合结构向更大跨度的发展。针对这一问题,提出在钢箱-混凝土组合连续梁中施加体外索的新技术,研究施加体外索对增强钢箱-混凝土组合连续梁负弯矩区混凝土的抗裂能力,提高钢箱-混凝土组合连续梁弹塑性结构性能的有利作用。经对比试验表明,施加体外索后,钢箱-混凝土组合连续梁负弯矩区混凝土的开裂荷载提高2.8倍,组合连续梁的弹塑性抗弯刚度提高29.35%,承载力提高34.67%,结构性能显著提高。在试验研究基础上,分析钢箱-混凝土组合连续梁负弯矩区局部力学性能与整体非线性结构性能的关系,揭示体外索提高钢箱-混凝土组合连续梁弹塑性结构性能的力学实质,给出承载力计算建议。研究结果可作为体外索钢箱-混凝土组合连续梁工程应用和理论分析的参考。更多还原

【Abstract】 Cracking of concrete flange slab in the negative moment area in steel-concrete composite continuous box beams affects its application for longer spans.A new technique of using external tendons in steel-concrete composite continuous box beams is proposed.As studies indicate,the external tendons may improve the crack resistance ability of concrete flange slab in the negative moment area and the elastoplastic structural performance of steel-concrete composite continuous box beams.Comparison with the experiments proves that the crack load,the elastoplastic stiffness and the load carrying capacity of steel-concrete composite continuous box beams are increased by 280%,29.35 % and 34.67 %,respectively.Based on the experimental results,the relationship between the local mechanical performance in the negative moment area and the nonlinear structural performance of steel-concrete composite continuous box beam is analyzed.The mechanical essence that the external tendons may improve the elastoplastic performance of steel-concrete composite continuous box beams is explained.The calculation formulas of load carrying capacity are suggested.更多还原