简支梁桥的计算-2荷载横向分布计算杠杆原理法A

1、,BRIDGE ENGRGPART II,Part 2 RC & PC beam bridge第二篇 钢筋混凝土和预应力混凝土梁式桥,Chapter 3 第三章 Analysis of simple supported beam bridge 简支梁桥的计算,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 transve

2、rse 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),P,o,x,z,3.3 Computation of Coefficients of Transverse Distribution of Loads 荷载横向分布计算,

3、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),o,x,y,z,S= 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

4、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,Diagram of the Coefficients of Transverse Distribution of Loads 横向分布系数图示,3.3 Metho

5、d 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,m3=1,m3=1/5,Rigid transverse connection 横梁刚度无限大,No transverse connection 横向无联系,1. Introduction 概述,3）荷载横向分布系数计算方法 杠杆原理法 Method based on mechanics of leverage 偏心压力法 Method based on stiffness t

6、ransverse connection 横向铰接梁（板）法 横向刚接梁法 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

7、computing the transverse distributive coefficient 荷载横向分布系数计算,2）适用范围 双主梁桥 有水平纵向缝的装配式桥 荷载作用于支点处 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/2,R1,P/2,R2,3,1,2,1,2,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