摘要
对于跨径小于50 m的桥梁,使用强配筋能很好地满足抗裂性能要求,但对于更大跨径的组合梁桥负弯矩抗裂,单独采用强配筋的方式已不能很好地满足桥梁抗裂需求。为了提高50~80 m连续组合梁桥负弯矩区桥面板抗裂性能,实现负弯矩区桥面板装配建造,提出一种适用不同抗裂能力的模数式预应力预制板。首先,设计了适合负弯矩区快速施工的3类预制板,其中A类板为中间位置普通预制板,B类板为带齿块的锚固板,C类板为端部锚固板,根据实际受力情况采用这3类预制板数量及长度组合以满足抗裂需要。其次,结合设计规范与数值模拟,验算使用这种抗裂技术时桥梁结构的内力、应力、挠度以及抗裂性能,验证其可行性。最后,进一步扩展到中跨径50~80 m、1.5~1.7边中跨比的组合梁桥,分别采用MIDAS进行结构抗裂验算与适用性分析。结果表明:采用后张预应力预制板抗裂技术可实现预制板翼缘应力在长短期组合下不出现拉应力,满足规范A类构件抗裂要求;养护龄期6个月的预制块在降低徐变作用方面效果明显,降幅均在48%左右,可满足50~80 m主跨跨径组合梁桥桥面板抗裂与钢箱梁强度控制规范要求;采用负弯矩预制板后,相较于规范计算结果,负弯矩长度范围略降低,仍可采用规范中偏安全的计算。
For bridges with spans less than 50 m,the use of strong reinforcement can well meet the requirements of anti-cracking performance,but for composite girder bridges with long spans,the use of strong reinforcement cannot well meet the needs of anti-cracking alone.In order to improve the cracking resistance of bridge panels in negative bending moment zone of 50-80 m continuous composite girder bridge and realize the construction of bridge panels in negative bending moment zone,a modular prestressed precast panel with different cracking resistance is proposed.First of all,3 types of precast panels suitable for rapid construction in negative bending moment area are designed,among which Class A is the ordinary precast panel in the middle position,Class B is the anchor panel with tooth block,and Class C is the end anchor plate.According to the actual stress situation,the number and length of the 3 types of precast panels are combined to meet the needs of anti-cracking.Secondly,combined with the design specification and numerical simulation,the internal force,stress,deflection and anti-cracking performance of the bridge structure by using anti-cracking technology are checked to verify the feasibility.Finally,it is further extended to the composite girder bridge with medium span of 50-80 m and 1.5-1.7 side to span ratio,and MIDAS is used to check the structural crack resistance and applicability analysis.The result shows that(1)the post-tensioned prestressed precast panel anti-cracking technology can realize that no tensile stress occurs in the flange stress of precast panel with the combination of long and short term,that meets the anti-cracking requirements of Class A members in the specifications;(2)the precast panels with a curing period of 6 months have an obvious effect on reducing the creep effect with a reduction of about 48%,which can meet the requirements of the bridge panel crack resistance and steel box girder strength control specifications for 50-80 m main span composite girder bridges;(3)when the negative bending moment precast panel is used,the length range of the negative bending moment is slightly reduced compared with the standard calculation result,and the standard partial safety calculation can still be used.
作者
方志杨
寿浙坤
林星昀
彭卫兵
FANG Zhi-yang;SHOU Zhe-kun;LIN Xing-yun;PENG Wei-bing(Hangzhou Institute of Communications Planning Design&Research Co.,Ltd.,Hangzhou,Zhejiang 310012,China;School of Civil Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310014,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2024年第2期116-125,共10页
Journal of Highway and Transportation Research and Development
基金
浙江省交通运输厅科研计划项目(2018006)。
关键词
桥梁工程
后张预制板技术
有限元计算
组合梁
收缩徐变
bridge engineering
post-tensioned precast panel technology
finite element calculation
composite beams
shrinkage and creep