1、第二章 主桁桿件內力計算第一節主力作用下主桁桿件內力計算1恒載橋面pi = 10kN/m,橋面系p2=6. 29kN/m,主桁架p3=14. 51,聯結系p=2. 74kN/m,檢查設備P5= 1. 02kN/m,螺栓、螺母和墊圈 p6=0. 02(p2+p3+p4),焊縫 p-=0. 015(p2+p3+p4)每片主桁所受恒載強度P二10+6. 29+14. 51+2. 74+1. 02+0. 02(6. 29+14. 51+2. 74)+0. 015(6. 29+14. 5 1+2. 74)/2= 17.69 kN/m,近似采用p =18 kN/mo2影響線面積計算弦桿影響線最大縱距)，=

2、妃4IH影響線面積A1A3: A = 18.42,/, = 73.68.6? = 0.2, y = 一: = -1.1641-92.1x12.664O = ；x92.1x(1.164) = 53.58 in=1.527mu/ 1 Cd / Q 八 A o 27.63x64.47 E2E4: /. = 27.63,/了 = 64.47,。= 0.3, y =1.5271-92.1x12.664Q=-x92.1xl.527 = 70.33m 2其他弦桿計算措施同上，計算成果列于表中（2）斜桿1+1 sinQ= 1.236Q=?（，+）+/；）= 1.1103 2Q= 1.11EOA1： k = 9

3、.21,Z2 = 82.89q = 0.1, y = 1.236xQ = ix92.1xl.ll = 51.23m2A3E4: /2 = 55.26,/； = 29.43, = 1.236 x = 0.742)LL236x紙= -0.37M = 921X0-742 =6.14 , 192.11 0.742 + 0.371a= 64=55.26+6.143 07 =9.21-6.14 = 3.07, a =:= 0.1127.63 + 3.07q = 1(6.14 + 55.26)x0.742 = 22.78 m,q = !(3.07 + 27.63)x(0.371) = 5.70 m,= 22

4、.78-5.70 = 17.08 m其他斜桿按上述計措施計算，并將成果列于表中。（3）吊桿y = 1.0, Q = x lx 18.42 = 9.21 in，23恒載內力Np = pd例如EqE2 =18.0 x30.14 = 542.54kNE4A5:=18.0 x(5.44)= 97.92加A瓦：% = 18.0 x9.21 = 165.78RN4活載內力(1)換算均布活載k按。及加載長度查表求得例如E2E4: a = 0.3, / = 92，陣竺竺= 44.24kN/m (每片主桁)k =四? = 50.95 kN/m(用內插法求得)A瓦：Q = 0.5,/= 18.42j 113.36“ e 1 xt/k = 56.68 kN/m2(2)沖擊系數弦桿、斜桿：1 + = 1 += 1+= 1.21240+L 40 + 92.1吊桿：1 + =9g=1 += 1.47940 + 18.42（3）靜活載內力MNp = g,例如EqE2 : M = 46.18x30.14 = 1391.92RNE4A5: M =50.95x(15.81) = 805.52即N； =52.9x10.37 = 548.57RNA,E5: Nk = 56.68x9.21 = 522.02AN（4）活載發展均衡系數值： =1 + ；（皿-。） 6a = N,/（l+）M，%”為跨中弦桿E的a