第2篇第3章 簡支梁橋的計算2荷載橫向分布計算杠桿原理法A

1、bridge engrgpart iipart 2 rc & pc beam bridge第二篇 鋼筋混凝土和預應力混凝土梁式橋chapter 3 第三章 analysis of simple supported beam bridge 簡支梁橋的計算 3.3 computation of coefficients of transverse distribution of loads 荷載橫向分布計算1. introduction 概述1）influence line and influence surface 影響線與影響面2）concept about the transvers

2、e distributive coefficient 荷載橫向分布概念3）method for computing the transverse distributive coefficient 荷載橫向分布系數(shù)計算方法 simple supported beam簡支梁one dimension一維桿件 influence line of the internal force內(nèi)力影響線 s= p 1(x) 1(x)poxz 3.3 computation of coefficients of transverse distribution of loads 荷載橫向分布計算1. introdu

3、ction 概述superstructure system上部結構系-two dimension 二維 influence surface of the internal force 內(nèi)力影響面 (x,y)p (x, y)oxyzs= p (x,y) 3.3 computation of coefficients of transverse distribution of loads 荷載橫向分布計算1. introduction 概述2） concept about the transverse distributive coefficient荷載橫向分布概念 若： s= p (x,y) p

4、 2(y) 1(x) 對比： s= p 1(x) pmax=mp 可以看出系數(shù) 2(y) 的作用相當于將荷載p沿橫向分配給指定的梁，使該梁承受p 的荷載。這樣一來， 可以將二維問題轉化為一維問題處理。 3.3 computation of coefficients of transverse distribution of loads 荷載橫向分布計算1. introduction 概述p1/2p1/2p2/2p2/2p1/2p1/2p2/2p2/2mp1mp2diagram of the coefficients of transverse distribution of loads 橫向分

5、布系數(shù)圖示橫向分布系數(shù)圖示 3.3 method for computing coefficients of transverse distribution of loads 荷載橫向分布系數(shù)計算two special cases荷載橫向分布系數(shù)的兩種特殊情形 p33pm3=1m3=1/5lrigid transverse connection 橫梁剛度無限大lno transverse connection橫向無聯(lián)系1. introduction 概述3）荷載橫向分布系數(shù)計算方法l杠桿原理法 method based on mechanics of leveragel偏心壓力法 method

6、 based on stiffness transverse connectionl橫向鉸接梁（板）法l橫向剛接梁法l比擬正交異性板法 3.3 method for computing coefficients of transverse distribution of loads 荷載橫向分布系數(shù)計算2. method based on mechanics of leverage 杠桿原理法1）assumption 原理假設 this method is based on the weak connection between girders 忽略主梁之間的橫向聯(lián)系作用，即假設橋面板在主梁上

7、斷開。 3.3 method for computing the transverse distributive coefficient 荷載橫向分布系數(shù)計算2）適用范圍l雙主梁橋l有水平縱向縫的裝配式橋l荷載作用于支點處l無中間橫隔梁的梁橋 3.3 method for computing the transverse distributive coefficient 荷載橫向分布系數(shù)計算2. method based on mechanics of leverage 杠桿原理法2. 杠桿原理法杠桿原理2#梁承受的荷載為： p/2r1p/2r231212支座反力影響線 pmppprrrqi2222121 3.3 method for computing the transverse distributive coefficient 荷載