上下组合式预制箱涵的配筋方法
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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 fpk; 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.
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 fpk; 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.
引文
[1]薛伟辰.预制混凝土框架结构体系研究与应用进展[J].工业建筑,2002,32(11):47-50.
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[3]河北省交通规划设计院. JTG/TD 65-04—2007公路涵洞设计细则[S].北京:人民交通出版社,2007.
[4]荣哲,孙玉品.城市综合管廊设计与计算[J].工业建筑,2013(S1):230-232.
[5]汪基伟,提桂娟,冷飞.弹性地基上框架结构内力计算方法[J].河海大学学报(自然科学版),2012,40(5):563-567.
[6]中华人民共和国住房和城乡建设部. GB 50838—2015城市综合管廊工程技术规范[S].北京:中国计划出版社,2015.
[7]中交公路规划设计院有限公司. JTG D62—2012公路钢筋混凝土及预应力混凝土桥涵设计规范[S].北京:人民交通出版社,2012.
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[2]中交公路规划设计院有限公司. JTG D60—2015公路桥涵设计通用规范[S].北京:人民交通出版社,2015.
[3]河北省交通规划设计院. JTG/TD 65-04—2007公路涵洞设计细则[S].北京:人民交通出版社,2007.
[4]荣哲,孙玉品.城市综合管廊设计与计算[J].工业建筑,2013(S1):230-232.
[5]汪基伟,提桂娟,冷飞.弹性地基上框架结构内力计算方法[J].河海大学学报(自然科学版),2012,40(5):563-567.
[6]中华人民共和国住房和城乡建设部. GB 50838—2015城市综合管廊工程技术规范[S].北京:中国计划出版社,2015.
[7]中交公路规划设计院有限公司. JTG D62—2012公路钢筋混凝土及预应力混凝土桥涵设计规范[S].北京:人民交通出版社,2012.
[8]汪基伟,张雄文,林新志.考虑黏结滑移的平面组合式单元模型研究与应用[J].工程力学,2008,25(1):97-102.