装配式防撞护栏竖向连接设计与准静态加载分析

Vertical Connection Design and Quasi-Static LoadingAnalysis of Prefabricated Anti-collision Barrier

目的 提出三种装配式防撞护栏竖向连接设计方案,即预埋H型钢焊接与浆锚连接相结合(方案一);预埋倒T型钢板焊接及浆锚连接相结合(方案二);“双环锚固”嵌固连接(方案三),解决装配式混凝土护栏抗剪和耐久性差、护栏竖向连接设计单一、装配式安装造价高昂等问题。方法 在考虑竖向连接构造与配筋的基础上,建立了相应的护栏-桥面板有限元模型,通过数值模拟开展装配式护栏准静态加载分析,研究上述三种装配式护栏的极限承载能力与失效特点,并简要对比其制造工艺与相对成本。结果 三种竖向连接方案的护栏最大承载力分别为600 kN、340 kN和400 kN;方案一呈现倒梯形屈服破坏,方案二与方案三出现应力集中并整体倾覆;方案一满足SA级桥梁护栏的设计要求,同时兼具工艺简便与相对成本较低的优点。结论 预埋H型钢焊接和浆锚连接相结合的竖向连接方式为优选方案,可为装配式防撞护栏的研究与应用提供参考。

Three design schemes for vertical connection of assembled concrete guardrail are put forward,which are the combination of pre-buried H section steel welding and grouting anchor connection(the scheme 1),preburied inverted T section steel welding and grouting anchor connection(the scheme 2),and“double loop rebar anchoring”embedded connection(the scheme 3).It will solve the problems of poor shear resistance and durability,single design of vertical connection and high cost of installation in assembled concrete guardrail.By considering the construction and reinforcement of the vertical connection,the corresponding finite element models of barrier-bridge deck plate were established,and the quasi-static loading analysis of prefabricated barrier was carried out.The research analyzes the ultimate bearing capacity and failure characteristics and makes a brief comparison between manufacturing process and relative cost.The results show that the maximum bearing capacity of the three kinds of barriers are 600 kN,340 kN and 400 kN respectively.The scheme 1 shows inverted trapezoid yield failure,and the scheme 2 and 3 show stress concentration and overall overturning.The scheme 1,which is about the combination of pre-buried H section steel welding and grouting anchor connection,meets the design requirements of SA grade bridge guardrail,and has the advantages of simple process and lower relative cost.It is selected as the optimum scheme,which can provide reference for the research and application of assembled guardrail.