第2篇第3章-简支梁桥的计算2荷载横向分布计算(杠杆原理法)A.pptx

3.3 Computation of Coefficients of Transverse Distribution of Loads 荷载横向分布计算1.Introduction 概述1）Influence line and influence surface 影响线与影响面2）Concept about the transverse distributive coefficient 荷载横向分布概念3）Method for computing the transverse distributive coefficient 荷载横向分布系数计算方法 Simple supported beam简支梁one dimension一维杆件 Influence line of the Internal force内力影响线 S=P 1(x)1(x)Poxz 3.3 Computation of Coefficients of Transverse Distribution of Loads 荷载横向分布计算1.Introduction 概述Superstructure system上部结构系-two dimension 二维 Influence surface of the Internal force 内力影响面 (x,y)P(x,y)oxyzS=P(x,y)3.3 Computation of Coefficients of Transverse Distribution of Loads 荷载横向分布计算1.Introduction 概述2）Concept about the transverse distributive coefficient荷载横向分布概念 若：S=P(x,y)P 2(y)1(x)对比：S=P 1(x)Pmax=mP 可以看出系数 2(y)的作用相当于将荷载P沿横向分配给指定的梁，使该梁承受P 的荷载。这样一来，可以将二维问题转化为一维问题处理。3.3 Computation of Coefficients of Transverse Distribution of Loads 荷载横向分布计算1.Introduction 概述P1/2P1/2P2/2P2/2P1/2P1/2P2/2P2/2mP1mP2Diagram of the Coefficients of Transverse Distribution of Loads 横向分布系数图示横向分布系数图示 3.3 Method for computing Coefficients of Transverse Distribution of Loads 荷载横向分布系数计算Two special cases荷载横向分布系数的两种特殊情形 P33Pm3=1m3=1/5lRigid transverse connection 横梁刚度无限大lNo transverse connection横向无联系1.Introduction 概述3）荷载横向分布系数计算方法l杠杆原理法 Method based on mechanics of leveragel偏心压力法 Method based on stiffness transverse connectionl横向铰接梁（板）法l横向刚接梁法l比拟正交异性板法 3.3 Method for computing Coefficients of Transverse Distribution of Loads 荷载横向分布系数计算2.Method based on mechanics of leverage 杠杆原理法1）Assumption 原理假设 This method is based on the weak connection between girders 忽略主梁之间的横向联系作用，即假设桥面板在主梁上断开。3.3 Method for computing the transverse distributive coefficient 荷载横向分布系数计算2）适用范围l双主梁桥l有水平纵向缝的装配式桥l荷载作用于支点处l无中间横隔梁的梁桥 3.3 Method for computing the transverse distributive coefficient 荷载横向分布系数计算2.Method based on mechanics of leverage 杠杆原理法2.杠杆原理法杠杆原理2#梁承受的荷载为：P/2R1P/2R231212支座反力影响线 3.3 Method for computing the transverse distributive coefficient 荷载横向分布系数计算2.杠杆原理法3）Example 计算实例(P573.3)3.3 Method for computing the transverse distributive coefficient 荷载横向分布系数计算