（1 天津大学建筑设计规划研究总院有限公司， 天津 300073； 2 天津大学建筑工程学院， 天津 300072； 3 山东万斯达建筑科技股份有限公司， 济南 250014； 4 天津市锦正房地产开发有限公司， 天津 300073）

［摘要］为研究“二阶段受力”对预应力混凝土钢管桁架叠合板整体受力性能的影响及该新型叠合板沿预应力方向的工作性能，进行了3组共6块预应力混凝土钢管桁架叠合板静力试验，通过对比得到不同受力状态叠合板的跨中挠度、开裂荷载、裂缝分布、预应力筋及混凝土的应变等。试验结果表明：预应力混凝土钢管桁架叠合板预制底板与叠合层混凝土协同工作性能良好，叠合板在加载过程中经历了弹性和弹塑性两个阶段，“二阶段受力”效应减小了叠合板开裂荷载，增大了最大裂缝宽度。经理论分析可知，叠合板弹性阶段刚度按《混凝土结构设计规范》（GB 50010—2010）计算值与实测值吻合较好且偏于安全，开裂后刚度按《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTG 3362—2018）计算与实测值最为接近。

［关键词］二阶段受力；预应力混凝土； 钢管桁架叠合板；静力试验；弹性阶段刚度

中图分类号：TU398-7文献标识码：A文章编号：1002-848X(2021)05-0080-06

Experimental study  on the mechanical behavior of prestressed concrete steel pipe truss composite slabs  under the influence of secondary force

YU Jinghai1,2, HE Mengjie2, ZHANG Shuhui3, ZHAO Yuyang4, TANG Yuxuan2

(1 Tianjin University Research Institute of Architectural Design and Urban Planning Co., Ltd., Tianjin 300073, China; 2 School of Civil Engineering, Tianjin University, Tianjin 300072, China; 3 Shandong One Star Construction Technology Co., Ltd., Jinan 250014, China; 4 Tianjin Jinzheng Real Estate Development Co., Ltd., Tianjin 300073, China)

Abstract:In order to study the influence of “secondary force” on the overall mechanical behavior of prestressed concrete steel pipe truss slabs and the working performance of this new type  composite slabs along the prestressing direction, the static test of three groups of six prestressed concrete steel pipe  truss composite slabs were constructed. The mid-span deflection, cracking load, crack distribution, prestressing tendons and concrete strain of the composite slabs with different stress states were obtained by comparison. The test results show that the prestressed concrete steel pipe truss composite composite slab prefabricated floor and the laminated concrete have good working performance. The composite slab experienced two stages of elasticity and elastoplasticity during the loading process. The “secondary force” effect reduces the cracking load of the composite slab and increases the maximum crack width. According to the theoretical analysis, the stiffness in the elastic stage of the composite slab is in good agreement with the measured value according to  Code for design of concrete structures(GB 50010—2010), the measured value of  stiffness after cracking is the closest to that calculated according to Code for design of highway reinforced concrete and prestressed concrete bridges and culverts (JTG 3362—2018).

Keywords:secondary force; prestressed concrete; steel pipe truss composite slab;static test;elastic stage stiffness

*天津市创新创业团队特殊支持项目（TJTZJH-GCCCXCYTD-1-3）。

作者简介：于敬海，博士，研究员，Email:yjh300072@163.com。