桁架式挂篮主桁架铰连接的受力分析和截面设计

Force Analysis and Section Design of Primary Truss Hinge Connection of Truss Type Hanging Basket

桁架式挂篮是桥梁施工中常采用的一种轻型挂篮,为了设计桁架式挂篮主桁架的横截面尺寸和分析铰连接的受力状况,基于桁架式挂篮,分别建立了菱形挂篮和三角挂篮主桁架的力学模型。基于铰链的概念和主桁架中构件的连接方式,将桁架式挂篮主桁架中的铰连接分为两类:连接两根构件且作用集中力的铰链和连接3根以上构件的铰链,分别介绍了各种铰连接处约束力的绘制方法。最后,以上海S3公路工程为背景,介绍了菱形挂篮主桁架截面尺寸的设计方法。计算结果表明,主桁架的截面尺寸与材料的许用应力、模板吊挂系统的重量、混凝土的重量、压杆长度、压杆两端约束情况和压杆材料有关。

Truss hanging basket is a kind of light hanging basket often used in bridge construction.In order to design the cross section size of the primary truss of the truss hanging basket and analyze the force of the hinge connection,the mechanical models of the primary trusses of rhombus and triangle hanging baskets were established respectively based on truss type hanging basket.Furthermore,based on the concept of the hinge and the connection mode of members in the primary truss,the hinge connections in the primary truss of the truss hanging basket are divided into two types:the hinge connecting two members and acting on a concentrated force and the hinge connecting more than three members.Then,The drawing methods of binding force at various hinge joints are introduced respectively.Finally,taking Shanghai S3 highway project as the background,the design method of the section size of the primary truss of the diamond hanging basket is introduced.?The calculation results show that the section size of the primary truss is related to the allowable stress of the material and the weight of the formwork hanging system,the weight of concrete,pressure bar length,pressure bar constraints at both ends and pressure bar material.