预应力UHPC-NC组合梁抗弯承载力计算方法  

Calculation method for flexural capacity of prestressed UHPC NC composite beams

作　　者：朱劲松[1,2] 秦亚婷 史腾 ZHU Jinsong;QIN Yating;SHI Teng(School of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学建筑工程学院,天津300072 [2]天津大学滨海土木工程与安全教育部重点实验室,天津300072

出　　处：《中南大学学报（自然科学版）》2022年第10期3989-4000,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52078333);天津市交通运输科技发展计划项目(2019B-21)。

摘　　要：为有效预测预应力超高性能混凝土−普通混凝土(UHPC-NC)组合梁的抗弯承载力,首先基于有限元方法建立纯弯曲作用下预应力UHPC-NC组合梁的数值分析模型,考虑材料非线性及复杂界面接触等问题,分析预应力筋配筋率、普通钢筋直径、普通钢筋强度等级以及高跨比等参数对预应力UHPC-NC组合梁抗弯承载力的影响规律;然后,基于平截面假定和截面平衡条件以及UHPC、普通混凝土、预应力筋和钢筋的本构关系,并考虑受拉区UHPC对抗弯承载力的贡献,提出预应力UHPC-NC组合梁的抗弯承载力理论计算公式,并将理论计算值与有限元模拟值进行对比。研究结果表明:提高预应力筋配筋率、普通钢筋直径和高跨比可以有效提高预应力UHPC-NC组合梁的抗弯承载能力;抗弯承载力公式计算值与有限元模拟值吻合良好,可为预应力UHPC-NC组合梁的设计和应用提供参考。In order to predict the flexural capacity of prestressed ultra-high performance concrete-normal concrete(UHPC-NC)composite beam effectively and guide the structural design of UHPC-NC composite beam bridge,a numerical analysis model of prestressed UHPC-NC composite beam during pure bending was established based on finite element method(FEM),considering material nonlinearity and complex interface contact.The finite element model was conducted to investigate the parametric analysis of the composite beams,and the influences of prestressed reinforcement ratio,reinforcement diameter,strength grade of steel bar and the height span ratio on the flexural capacity of prestressed UHPC-NC composite beams were analyzed.Then,considering the contribution of UHPC in tensile zone to the flexural capacity,the calculation formula of the flexural capacity of prestressed UHPC-NC composite beam was established based on the assumption of flat section,the condition of cross-section equilibrium as well as the constitutive relation of UHPC,concrete,prestressed bar and steel bar.The calculated value of the formula was compared with that of the finite element calculation.The results show that the flexural capacity of prestressed UHPC-NC composite beams can be effectively improved by increasing the prestressed reinforcement ratio,reinforcement diameter and the height span ratio.The calculated values of the proposed method are in good agreement with the finite element calculation results,which can provide a reference for the design and application of prestressed UHPC-NC composite beams.

关 键 词：超高性能混凝土组合梁 有限元分析 抗弯承载力 预应力混凝土结构 普通混凝土 

分 类 号：TU528.01[建筑科学—建筑技术科学]