单向预应力UHPC连续箱梁桥面体系优化设计研究

发布时间：2018-07-09 23:08

本文选题：UHPC箱梁 + 密集横隔板　；参考：《土木工程学报》2017年11期

【摘要】：为方便布置体内预应力束和进一步改善桥面板受力状态,对大跨单向预应力UHPC(Ultra-high Performance Concrete)连续箱梁桥的桥面体系进行优化设计,提出新型正交异性UHPC矮肋板桥面体系方案。以广东省某桥为工程背景,进行了基于正交异性UHPC矮肋板桥面体系方案的UHPC箱梁结构试设计并开展相关的试验研究。结果表明:(1)与矩形桥面板方案相比,优化的正交异性UHPC箱梁矮肋板桥面体系自重可减少17.0%,并可在矮肋板纵肋处方便地布置体内束;与华夫桥面板方案相比,可在不明显增加桥面体系自重的前提下,大幅减小桥面板的纵向应力,降幅可达46.8%;(2)基于正交异性UHPC矮肋板桥面体系的UHPC箱梁方案试设计整体计算满足受力要求,桥面体系计算中标准组合作用下桥面板最大纵向拉应力2.66MPa,横隔板最大横向应力6.09MPa;(3)试验及计算结果表明,矮肋板试件初裂名义应力8.84MPa,抗裂设计名义应力限值10.70MPa,UHPC箱梁横隔板上弦板底面横向应力达到8.43MPa时仍处于线弹性受力阶段,表明试设计方案能满足设计要求。
[Abstract]:In order to facilitate the layout of prestressing tendons and further improve the stress state of deck slab, the deck system of long-span unidirectional prestressed UHPC (Ultra-high performance concrete) continuous box girder bridge is optimized and a new orthotropic UHPC slab deck system scheme is proposed. Taking a bridge in Guangdong Province as the engineering background, the UHPC box girder structure based on orthotropic UHPC short-ribbed slab bridge surface system was designed and tested. The results show that: (1) compared with the rectangular bridge deck scheme, the weight of the optimized orthotropic UHPC box girder bridge deck system can be reduced by 17.0, and the body beam can be conveniently arranged at the longitudinal rib of the low ribbed slab, and compared with the Waff bridge deck scheme, On the premise of not increasing the weight of deck system, the longitudinal stress of deck slab can be greatly reduced by 46.8.The (2) the overall design of UHPC box girder scheme based on orthotropic UHPC rib slab deck system can meet the requirements of stress. In the calculation of bridge deck system, the maximum longitudinal tensile stress of bridge deck plate is 2.66 MPA and the maximum transverse stress of transverse partition plate is 6.09 MPA under the action of standard combination. (3) the test and calculation results show that, The nominal stress of initial crack is 8.84 MPA, and the nominal stress limit of anti-crack design is 10.70 MPA. When the transverse stress of the upper chord plate of UHPC box girder reaches 8.43 MPA, it is still in the stage of linear elastic force, which indicates that the test design scheme can meet the design requirements.
【作者单位】：湖南大学土木工程学院;湖南大学风工程与桥梁工程湖南省重点实验室;山西省交通科学研究院桥梁工程防灾减灾山西省重点实验室;上海市政工程设计研究总院(集团)有限公司;
【基金】：国家自然科学基金(51378194) 广东省交通运输厅科技项目(2013-02-036) 湖南省研究生科研创新项目(CX2017B119)
【分类号】：U443.31

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