摘要
为深入研究钢桁架-混凝土组合梁的界面工作协调性及整体结构力学性能,建立可为工程应用的简明算法,选取某钢桁架-混凝土组合连续梁作为研究对象,采用精细化有限元分析方法,以多维度单元相组合的形式建立其三维数值空间模型。以中支点截面及中支点附近2 m处截面、边跨跨中截面以及边支点截面处共5组剪力钉为分析对象,计算不同直径剪力钉的荷载-滑移关系曲线。研究预应力混凝土桥面板(简称PC板)的强度、厚度以及剪力钉的形式3种结构参数对PC板与钢桁架界面滑移量的影响程度。结合皮尔逊相关系数给出界面工作协调性对各参数的敏感度,提出了考虑PC板强度、厚度和剪力钉形式的界面滑移量计算公式。通过挠度与应力的变化特征确定钢桁架-混凝土组合梁的整体力学性能,并提出组合梁整体结构的最大挠度预测公式。研究结果表明:随着PC板强度的增加,在荷载较小时,界面滑移量呈下降趋势,荷载较大时,界面滑移量呈上升趋势;PC板厚度对界面滑移量的影响规律不明显;剪力钉的形式对界面滑移量有直接影响,剪力钉直径越小,PC板与钢桁架的界面工作协调性越差。组合梁最大挠度随PC板强度提高而减小,随PC板厚度增加呈现先减小后增大的趋势,剪力钉直径对组合梁最大挠度影响较小。PC板强度变化对钢桁架最大正应力影响不大,但对PC板最大压应力影响幅度超过20%。当PC板厚度与钢桁架高度比值在0.0506~0.0532时,组合梁的界面局部工作特性及整体力学性能较为均衡。所提公式简洁,该研究成果可为钢桁架-混凝土组合桥梁全寿命建造与安全运维提供理论依据。
In order to deep study the interface working coordination and overall structure mechanical properties of steel truss-concrete composite bridge girders,and establish a concise calculation method for engineering applications,a steel truss-concrete composite continuous girder was selected as research object and refined finite element analysis method was adopted.A three-dimensional numerical model of steel truss-concrete composite girder was established by the combination of multi-dimensional elements.Five groups of shear studs which at the middle span fulcrum section and 2 m away from it sections,and at the side span middle section and the side span fulcrum section were used as the analysis objects,the load-slip relationship curves of shear studs with different diameters were calculated.The influence degree of the strength and thickness of prestressed concrete bridge slab(PC slab for short),and the form of shear studs on the interface slip between PC slab and steel truss was studied.The sensitivity of the interface working coordination to each parameter was proposed based on Pearson correlation coefficient,and a calculation formula of interface slip was proposed,considering the strength and thickness of PC slab and the form of shear studs.Then overall mechanical properties of steel truss-concrete composite girders were determined by the variation characteristics of deflection and stress.And the maximum deflection prediction formula of overall structure of composite girder was proposed.The results show that with the increase of strength of PC slab,interface slip decreases when the load is small,and increases when the load is large.Thickness of PC slab has no obvious influence on the interface slip,while the form of shear studs exerts direct effect on the interface slip,smaller diameter of shear studs can cause worse interface working coordination of PC slab and steel truss.The maximum deflection in composite girder decreases with the increase of strength of PC slab,decreases first and then increases with the increase of thickness of PC slab.Shear studs has little influence on the maximum deflection of composite girders.Furthermore,the strength variation of PC slab has little influence on the maximum normal stress of steel truss,but the influence range on the maximum compressive stress of PC slab is more than 20%.Interface local working and overall mechanical properties of composite girders are more balanced when the ratio of PC slab thickness to steel truss height is between 0.0506 to 0.0532.The proposed calculation formula is concise,and research results can provide a theoretical basis for life cycle construction and safe operation,and maintenance of steel truss-concrete composite bridge girders.2 tabs,12 figs,29 refs.
作者
赵晓翠
张岗
王宝莹
王世超
汤陈皓
张永飞
ZHAO Xiao-cui;ZHANG Gang;WANG Bao-ying;WANG Shi-chao;TANG Chen-hao;ZHANG Yong-fei(School of Highway,Chang’an University,Xi’an 710064,Shaanxi,China)
出处
《长安大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第6期77-89,共13页
Journal of Chang’an University(Natural Science Edition)
基金
陕西省杰出青年科学基金项目(2022JC-23)
陕西省交通运输科研项目(20-45k)
中央高校基本科研业务费专项资金项目(300102212907)。
关键词
桥梁工程
钢桁架-混凝土组合梁
精细分析
界面工作协调性
力学性能
PC板
敏感度
bridge engineering
steel truss-concrete composite girder
fine analysis
interface working coordination
mechanical property
PC slab
sensitivity
