| 陈东,方园,宣浩,康星,丁磊.大跨度预应力混凝土钢管桁架预制底板模拟施工荷载下力学性能研究[J].安徽建筑大学学报,2026,34(4):29-42 |
| 大跨度预应力混凝土钢管桁架预制底板模拟施工荷载下力学性能研究 |
| Research on the Mechanical Behavior of Large-span Prestressed Concrete Steel-tube Truss Precast Slabs Under Simulated Construction Loads |
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| DOI： |
| 中文关键词: 钢管桁架 预制底板 力学性能 参数化分析 开裂荷载计算 |
| 英文关键词: steel-tube truss precast slab mechanical property parameter analysis cracking load calculation |
| 基金项目:高校学科（专业）带头人培育项目（DTR2023028）；中国建筑国际科技研发项目（CSCI-2023-Z-11-2）；安徽省自然科学基金项目（19080885ME173） |
| 作者 | 单位 | | 陈东 | College of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China | | 方园 | College of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China | | 宣浩 | College of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China | | 康星 | Anhui Jinggong Green Building Group Co., Ltd.,Fuyang 236300,China | | 丁磊 | Anhui Jinggong Green Building Group Co., Ltd.,Fuyang 236300,China |
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| 中文摘要: |
| 为研究大跨度预应力混凝土钢管桁架预制底板在模拟施工荷载下（即浇筑过程中）的力学性能，对4块跨度4.2 m、宽度2.1～4.2 m的不同尺寸底板进行分级静力加载试验，分析开裂荷载、跨中挠度、裂缝分布、混凝土及钢管应变等结构性能的变化规律。结果表明：钢管桁架与混凝土底板协同工作性能良好，所有腹筋均未屈服，并未脱出底板混凝土；板底跨中处首先开裂，裂缝沿跨中两侧均匀分布；各试件开裂荷载分布在0.46～0.53 kN/m²之间，对应的挠度均远小于规范限值L/200（21 mm），验证了免支撑施工的可行性。数值模拟极限承载力误差小于10%，受力变形和应力分布与试验吻合。关键参数化分析得出：灌浆料填充使承载力提升1倍左右；同直径钢筋桁架承载力比钢管桁架高33.3%，但板底开裂损伤更严重；钢管数量增加2根，承载力提升20.5%；桁架高度从76 mm增至96 mm，承载力提升46.3%，可在保证叠合板厚度的前提下适当增加桁架高度。此外，以试验数据为基础，开展钢管桁架预应力混凝土预制底板的开裂荷载计算，最终误差为45%～55%。建议后续针对钢管与混凝土的界面黏结滑移效应等核心机理开展深入研究，以建立精准计算模型。 |
| 英文摘要: |
| To explore the mechanical behavior of large-span prestressed concrete precast slabs with steel tube trusses under simulated construction loads during concrete pouring, graded static loading tests were carried out on four slabs with a span of 4.2 m and widths ranging from 2.1 to 4.2 m. The variations in structural performance, such as cracking load, mid-span deflection, crack distribution, and strains in concrete and steel tubes, were investigated. The results indicate that the steel tube truss and the concrete slab demonstrated favorable composite action. All web reinforcements neither reached the yield state nor were pulled out from the slab concrete. Cracking initiated at the mid-span of the slab soffit and propagated symmetrically on both sides. The cracking loads of the specimens ranged from 0.46 to 0.53 kN/m², and the corresponding deflections were all well below the code-specified limit of L/200 (21 mm), thereby validating the feasibility of support-free construction. Numerical simulation predicted the ultimate bearing capacity with an error of less than 10%, and the simulated deformation and stress distributions were in good agreement with the experimental results. Key parametric analysis shows that grouting the steel tubes approximately doubled the bearing capacity. A reinforcing bar truss of the same diameter provided a 33.3% higher capacity than the steel tube truss, but led to more severe cracking damage at the slab soffit. Increasing the number of steel tubes by two increased the capacity by 20.5%. Increasing the truss height from 76 mm to 96 mm improved the capacity by 46.3%, suggesting that the truss height can be appropriately increased while maintaining the required thickness of the composite slab. Furthermore, based on the test data, the cracking load of the steel tube truss prestressed concrete precast slab was calculated, with an error of 45%–55%. Therefore, it is recommended that future research focus on the core mechanisms, especially the interfacial bond slip behavior between the steel tube and concrete, to establish a more accurate calculation model. |
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