预制装配式承台结合面抗剪承载力对比研究

Research on the shear bearing capacity of the prefabricated pile caps joint surface

预制装配式承台在桥梁结构中正逐渐推广应用,但桥梁行业现行规范对此类结构尚无相关设计规定。结合面作为预制装配结构的关键受力面和薄弱位置,有必要对其抗剪承载能力进行深入研究。结合采用预制装配式承台的工程实例,对中国规范、美国规范关于预制装配式承台结合面抗剪承载力进行对比研究。研究结果表明,各个规范对于结合面抗剪承载力的认知机理存在差别,导致不同规范给出的结合面抗剪承载力存在较大差异:《预制装配整体式钢筋混凝土结构技术规范》(SJG18-2009)抗剪承载力最低,《Building Code Requirements For Structural Concrete And Commentary》(ACI-318M-19)抗剪承载力最高,《装配式混凝土结构技术规程》(JGJ1-2014)居中。综合安全性与经济性考虑,推荐预制装配式承台结合面抗剪承载力按照《装配式混凝土结构技术规程》(JGJ1-2014)或ACI-318M-19计算。本研究扩展了装配式结构规范的适用领域,为预制装配承台的设计提供了范例,对后续同类设计项目具有一定的参考意义。

Prefabricated pile caps are gradually being popularized and applied in bridge structures,but there are no relevant design regulations for such structures in the current specifications of the bridge industry.The joint face between precast concrete and cast-in-place concrete is the key plane and weak plane for shear transferring of the prefabricated assembly structure,and it is necessary to research the shear bearing capacity of the joint face.In this paper,based on an engineering example using prefabricated pilecaps,a comparative study is made on the relevant provisions of the Chinese code and the American code on the shear bearing capacity of the prefabricated cap joint surface.The research results show that there are differences in the cognition mechanism of the shear bearing capacity of the joint surface in different codes,which leads to a large difference in the calculated shear bearing capacity:《Technical specification for prefabricated monolithic reinforced concrete structures》(SJG18-2009)has the lowest shear bearing capacity,《Building Code Requirements For Structural Concrete And Commentary》(ACI-318M-19)has the highest shear bearing capacity,and《Technical specification for precast concrete structures》(JGJ1-2014)is in the middle.To ensure structural safety and economy,it is recommended to design in accordance with the《Technical specification for precast concrete structures》(JGJ 1-2014)or ACI-318M-19.This study expands the applicable field of prefabricated structural specifications,provides an example for the design of prefabricated assembly platforms,and has certain reference significance for subsequent similar design projects.