摘要
针对预应力混凝土(PC)宽浅腹T梁设计和应用中存在的问题,建立了确定PC宽浅腹T梁截面基本特性的计算方法和20 m跨径PC宽浅腹T梁桥的工程模型。采用经试验验证的数值模拟方法对选定的PC宽浅腹T梁的弯曲力学行为开展研究,揭示PC宽浅腹T梁在不同设计参数下的力学响应与空心板的协同工作性能,以及不同日照角度作用下的变形受力机理,并获取其抗弯性能响应规律和日照作用下的温度效应反馈特点。研究结果表明:建立的计算方法能够对PC宽浅腹T梁截面的基本参数进行快速计算;提高钢筋强度可有效提升PC宽浅腹T梁在屈服阶段的抗弯刚度和抗弯承载力,但仅提高混凝土强度或仅提高张拉预应力对梁体的全过程抗弯刚度和抗弯承载力的影响较小;PC宽浅腹T梁具备与空心板梁协同工作的性能,可用于替换病害严重的空心板梁;在日照大温差作用下,PC宽浅腹T梁会在跨中产生较大的弯曲上挠,并对主梁接缝处产生较大的拉应力,须增强其横向连接刚度,推荐采用增设钢筋网来改善接缝处开裂问题;PC宽浅腹T梁腹板内的温差应力分布形式呈指数函数,腹板局部温度分布较PC高薄腹T梁更为均匀;提出的温差应力分布公式简洁方便,易于工程应用;提出的设计建议可为此类桥梁的全寿命建造与安全运营提供理论依据。
Aimed at the problems in the design and application of prestressed concrete(PC)wide-shallow web T-girders,the calculation method for determining the basic section property of PC wide-shallow web T-girders and the 20 m span engineering model was established,then the numerical simulation method that verified by experimental was used to study the flexural mechanical behavior of PC wide-shallow web girders.The PC wide-shallow web T-girder’s flexural mechanical response under the influence of different design parameters,the cooperative working performance with hollow slab girders and the deformation mechanism under different sunshine angles were explored to obtain the mechanical behavior response rule and temperature effect feedback.The results show that the established calculation method can be used to calculate the section parameters of PC wide-shallow web T-girders quickly.The flexural stiffness and flexural bearing capacity of PC wide-shallow web T-girders at yield stage can be effectively improved with increased reinforcement.But only increasing the strength of concrete or only increasing the prestress degree has little effect on the whole process flexural stiffness and flexural bearing capacity.PC wide-shallow web T-girders have the ability to work in conjunction with hollow slab to replace the hollow slab girders with serious diseases.PC wide-shallow web T-girders produce a larger flexural up warping in mid-span and a larger tensile stress on joints under the action of large temperature difference,so that the stiffness of the transverse connection must be enhanced and the additional of steel mesh is recommended to ameliorate cracking.The distribution of temperature difference stress in the web of PC wide-shallow web T-girder is an exponential function,and the local temperature distribution of the web is more uniform than that of the PC high-thin web girder.The proposed temperature difference stress distribution formula is concise,convenient and easy for engineering application.The proposed design suggestions can be provided theoretical guidance for the lifetime construction and safe operation of such bridges.2 tabs,15 figs,31 refs.
作者
汤陈皓
张岗
侯永刚
宋超杰
陆泽磊
朱建瑞
谢波
TANG Chen-hao;ZHANG Gang;HOU Yong gang;SONG Cha-jie;LU Ze-lei;ZHU Jian-rui;XIE Bo(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Ningxia Highway Survey and Design Institute Co Ltd.,Yinchuan 750000,Ningxia,China;Road&Bridge South China Engineering Co.,Ltd.,Guangzhou 528404,Guangdong,China)
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第3期75-85,共11页
Journal of Chang’an University(Natural Science Edition)
基金
国家自然科学基金项目(51878057)
宁夏回族自治区交通运输厅建设科技项目(201700166)。
关键词
桥梁工程
力学行为
数值模拟
预应力宽浅腹T梁
温度效应
bridge engineering
mechanical behavior
numerical simulation
PC wide-shallow web T-girder
temperature effect
