《20米、40米箱梁预应力筋伸长量计算》由会员分享,可在线阅读,更多相关《20米、40米箱梁预应力筋伸长量计算(6页珍藏版)》请在金锄头文库上搜索。
1、箱梁预应力筋伸长量计算书一、工程简况我分部桥梁上部结构采用20m、40m箱梁,结构体系为先简支后连续。箱梁预应力束采用公称直径s15.2预应力钢绞线,其公称面积Ap=140mm2,抗拉标准强度fpk=1860Mpa,弹性模量Ep=2.01105Mpa,技术标准符合GB/T5224-2014,配M15-3、M15-4和M15-5系列锚具,预应力管道采用波纹管。二、计算说明钢绞线理论伸长值LL(mm)可按式(1-1)计算:LL=PPLAPEP (1-1)式中:PP预应力筋的平均张拉力(N),直线筋取张拉端的拉力;两端张拉的曲线筋,计算方法见式(1-2);L预应力筋的长度(mm);AP预应力筋的截面
2、面积(mm);EP预应力筋的弹性模量(N/mm)。预应力筋平均张拉力应按式(1-2)计算:PP=P(1-e-(kx+)kx+ (1-2)式中:PP预应力筋的平均张拉力(N);P预应力筋张拉端的张拉力(N);从张拉端至计算截面的孔道长度(m);从张拉端至计算截面曲线孔道部分切线的夹角之和(rad);k孔道每米局部偏差对摩擦的影响系数0.0015;预应力筋与孔道壁的摩擦系数0.25。注:当预应力筋为直线时PP=P。1.锚下控制力:k=0.751860Mpa=1395Mpa;2.张拉控制力:P=kAp=1395140=195.3kN;3.弹性模量:Ep=2.01105Mpa;4.公称面积:Ap=14
3、0mm2。三、计算过程3.1 20米箱梁边跨(半跨)伸长值计算:N1筋:AB=20.927/2-0.65-BC-CD=20.927/2-0.65-2.128-2.8798=4.8057;BC=R*/180*=30*5.5/180*=2.8798;CD=2.128;=5.5/180*=0.09599rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB4.805700.007208550.007183976.53.3BC2.87980.095990.02831720.027920969.52.0CD2.12800.0031920.003187942.41.49.8135
4、6.7N2筋:AB=20.938/2-0.65-BC-CD=20.938/2-0.65-3.582-2.8798=3.3572;BC=R*/180*=30*5.5/180*=2.8798;CD=3.582;=5.5/180*=0.09599rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB3.357200.00503580.005023781.22.3BC2.87980.095990.02831720.027920777.32.0CD3.58200.0053730.005359755.62.49.8196.7N3筋:AB=20.801/2-0.65-BC-CD=2
5、0.801/2-0.65-0.7330-8.001=1.0165;BC=R*/180*=30*1.4/180*=0.7330;CD=8.001;=1.4/180*=0.0244rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB1.016500.00152480.0015236781.20.7BC0.73300.02440.00720950.0071836780.00.5CD8.00100.01200150.0119298774.45.59.75056.73.2 20米箱梁中跨(半跨)伸长值计算:N1筋:AB=20.902/2-0.65-BC-CD=20.902/2
6、-0.65-2.8798-0.537=6.3842;BC=R*/180*=30*5.5/180*=2.8798;CD=0.537;=5.5/180*=0.09599rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB6.384200.0095760.009530781.24.4BC2.87980.095990.0283170.027920773.762.0CD0.537000.00080550.0008052752.150.39.8016.7N2筋:AB=20.936/2-0.65-BC-CD=20.902/2-0.65-2.8798-2.015=4.9232;BC
7、=R*/180*=30*5.5/180*=2.8798;CD=2.015;=5.5/180*=0.09599rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB4.923200.00738480.0073576781.23.4BC2.87980.095990.0283170.027920775.452.0CD2.01500.00302250.0030179753.801.39.8186.7N3筋:AB=20.701/2-0.65-BC-CD=20.701/2-0.65-2.8798-7.901=1.0665;BC=R*/180*=30*1.4/180*=0.733;
8、CD=7.901;=1.4/180*=0.0244rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB1.066500.0016000.0015987585.90.74BC0.73300.02440.00719950.0071736584.960.51CD7.90100.011850.01178580.775.449.70056.693.3 40米箱梁边跨(半跨)伸长值计算:N1筋:AB=40.970/2-0.65-BC-CD=40.970/2-0.65-3.8397-2.578=13.4173;BC=R*/180*=55*4/180*=3.8397;CD=2.57
9、8;=4/180*=0.0698rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB13.417300.0201260.019925976.59.3BC3.83970.06980.0232100.022943957.02.6CD2.57800.0038670.003860935.11.719.83513.6N2筋:AB=40.960/2-0.65-BC-CD=40.960/2-0.65-3.8397-4.580=11.4103;BC=R*/180*=55*4/180*=3.8397;CD=4.580;=4/180*=0.0698rad。名称L(m)(rad)kx+1
10、-e-(kx+)P(KN)LL(cm)AB11.410300.0171150.016969976.57.9BC3.83970.06980.0232100.022943959.92.6CD4.58000.0068700.006846937.93.119.8313.6N3筋:AB=40.950/2-0.65-BC-CD=40.950/2-0.65-3.8397-6.582=9.4033;BC=R*/180*=55*4/180*=3.8397;CD=6.582;=4/180*=0.0698rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB9.403300.0141050
11、.0140061171.86.5BC3.83970.06980.0232100.0229431155.42.6CD6.58200.0098730.0098241128.94.419.82513.5N4筋:AB=40.940/2-0.65-BC-CD=40.940/2-0.65-3.8397-8.584=7.3963;BC=R*/180*=55*4/180*=3.8397;CD=8.584;=4/180*=0.0698rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB7.396300.0110940.0110331171.85.1BC3.83970.06980.02
12、32100.0229431158.92.6CD8.58400.0128760.0127931132.35.819.8213.5N5筋:AB=40.930/2-0.65-BC-CD=40.930/2-0.65-3.8397-10.586=7.3963;BC=R*/180*=55*4/180*=3.8397;CD=10.586;=4/180*=0.0698rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB5.389300.0080840.0080511171.83.7BC3.83970.06980.0232100.0229431162.42.6CD10.58600.0158790.0157541135.77.119.81513.4N6筋:AB=40.897/2-0.65-BC-CD=40.897/2-0.65-0.5236-15.528=3.7469;BC=R*/180*=30*1/180*=0.5236;CD=15.528;=1/180*=0.01745rad。名称L(m)(rad)kx+1-e-(kx+)P(KN)LL(cm)AB3.746900