上下组合式预制箱涵的配筋方法  

Reinforcement design of upper and lower U-section box culverts

作　　者：汪基伟[1] 姚燚 孔维良 Wang Jiwei;Yao Yi;Kong Weiliang(College of Civil&Transportation Engineering,Hohai University,Nanjing 210098,China;Nanjing Municipal Design&Research Institute,Nanjing 210008,China)

机构地区：[1]河海大学土木与交通学院,南京210098 [2]南京市政设计研究院,南京210008

出　　处：《黑龙江科技大学学报》2018年第6期643-648,共6页Journal of Heilongjiang University of Science And Technology

摘　　要：针对现行规范计算组合式箱涵拼缝接头弯矩和拼缝外缘张开量所需的旋转弹簧常数较难获得的问题,提出以整体式箱涵内力计算侧墙所需预应力筋及各构件普通钢筋用量的设计原则。对不同尺寸、不同荷载时上下组合式和整体式箱涵钢筋混凝土的承载力开展有限元计算。结果表明,当预应力筋布置在侧墙外侧、张拉控制应力取值不小于0. 70fpk时,组合式和整体式箱涵内力分布十分接近。预应力筋对侧墙产生的预压应力能够有效限制组合式箱涵侧墙裂缝发生和扩展以及拼缝张开。侧墙抗弯刚度增大时,组合式箱涵侧墙中部、顶板和底板的变形小于整体式箱涵。算例验证了文中所提设计原则的合理性和适用性。该研究为大截面预制组合式箱涵的分割和配筋提供了方法参考。This paper is an effort to eliminate the notorious difficulties resulting from obtaining the rotational spring constant K required for calculating,according the current specification,the moment and the opening amount of the joint of combined box culverts and proposes the design principle that the determination of the required prestressing tendons in side walls and common reinforcement amount in each component of modular box culverts is obtained by the internal force of the integral box culverts.The research is focused on the calculation of modular and integral box culverts with different sizes and loads using the reinforced concrete finite element method.The results show that the internal force distribution of combined and integral box culverts are very close when the prestressed tendons are arranged on the outside of the side walls and the tension control stress is not less than 0.70 f pk;the prestressing stress produced by the prestressing tendons on the side wall allows an effective restriction of the occurrence and expansion of cracks in the side wall of composite box culvert and the opening of joint joints;and the increased bending stiffness of the side wall leaves the deformation of the middle,the roof and the bottom plate of the side wall smaller than that of the integral box culvert.The study verifies the rationality and applicability of the design principles and could provide a novel method for the segmentation and reinforcement of large section prefabricated modular box culvert.

关 键 词：组合式箱涵 配筋方法 预应力筋用量 变形 张拉控制应力值 

分 类 号：U449.1[建筑科学—桥梁与隧道工程]