空心薄壁墩盖梁施工受力计算书

--1---2-盖梁施工验算书根据JTJ025-86公路桥涵钢结构及木结构设计规范，临时性结构的容许应力提高系数为1.3~1.4，以Q235(A3)为例：弯曲应力[σw]=145Mpa,作为临时性结构提高后的弯曲应力[σw]=203Mpa，已接近屈服点，实际计算弯曲应力中按屈服强度235MPa做为验算控制指标。剪应力[σ]=85Mpa,临时性结构提高后的剪应力[σ]=119Mpa。一、荷载计算①、梁重q=2.5×（0.9+0.8）×3=12.75t/m（全截面段）对支撑杆件施加作用力的砼总重量=全截面段+渐变段+挡块+垫石=(（0.9+0.8）×3×0.5+（1.7+0.9）×2.425÷2×3＋0.5×0.56×3+0.8×0.8×0.175×2)×2×2.5=（2.55+9.46+0.84+0.224）×2×2.5=65.37t模板荷载：对应墩顶的6.5m范围：0.9KN/㎡×(1.7×2)×6.5=1.989t盖梁悬臂部分全断面0.5m两侧:0.9KN/㎡×(1.7×2+3)×0.5×2=0.288×2=0.576t盖梁悬臂部分渐变段2.425m两侧:0.9KN/㎡×（（1.7+0.9）×2.425÷2×2+2.554×3）×2=2.514t挡块模板：0.9KN/㎡×(0.5×0.56+0.5×3)×4=0.641t∑模板=5.72t--3-施工人员，施工料具荷载：1.0kpa×3m=0.3t/m0.3t/m×12.35=3.705t砼倾倒与振捣荷载：4kpa×3m=1.2t/m1.2t/m×（12.35-5.5）=8.22t荷载分布系数：砼取1.05，其它取1.1荷载计算：1.05×65.37+1.1×（5.72+3.705+8.22）=68.64+19.41=88.05t②、(4根45b工字梁：12×0.087485×4=4.2t)拟采用槽钢横梁、木楔等计8t全部荷载：P=88.05+4.2+8=100.25t≈100t二、串杠受力验算D=10cm碳圆（尺寸及参数：d=100mm,Ix=491cm4,wx=98.2cm3,截面面积=78.5cm2,理论重量=61.7（kg/m））18工字钢（尺寸及参数：h=180mm,b=94mm,Ix=1660cm4,wx=185cm3,截面面积=30.756cm2，理论重量=24.143（kg/m））20b工字钢（尺寸及参数：h=200mm,b=102mm,Ix=2500cm4,wx=250cm3,截面面积=39.578cm2，理论重量=31.069（kg/m））25a工字钢（尺寸及参数：h=250mm,b=116mm,Ix=5020cm4,wx=402cm3,截面面积=48.541cm2，理论重量=38.105（kg/m））38kg/m（U74普通碳素轨）（尺寸及参数：h=134mm,b上=68mm,b下=114mm,Ix=1204.4cm4,wx=178.9cm3,截面面积=49.5cm2，理论重量=38（kg/m））--4-支撑点一端受集中力：P=100/4=25t1）试算d=10cm碳圆（考虑每侧采用两根bI40做横梁）a、剪力验算：钢）（385][847.311005.014.325000076.3184713300785.025000005.014.32562222AMPaMPaPamNmtAP满足要求b、弯曲应力验算：MPacmmNWMcmrd5.361102.98142.02500002.9840982.0W6333（高于235Mpa的屈服点,不满足要求）W=毛截面抵抗矩c、刚度验算mmmmmtEIPlfA72.024.01024.03093300496.74610491101.2310144.02533811433--5-444491641014.364cmdIπ悬臂构件计算跨度取实际长度2倍，L=0.144*2=0.288m,0.288m/400=0.72mm（L=0.144mbI40b=14.4cm,h=40cm）满足要求结论：不考虑采用。2）试算18I工字钢（考虑每侧采用两根bI40做横梁）a、剪力验算：钢）（385][28.8110756.302500005.8128495210756.30250000756.30252242AMPaMPaPamNcmtAP满足要求b、弯曲应力验算：MPaMPammtcmtWMAN235][88.2756.19428.81c185101144.025756.3025362不满足要求c、刚度验算mmmmmtEIPlfA72.0071.010071.0101660101.2310144.02533811433悬臂构件计算跨度取实际长度2倍，L=0.144*2=0.288m,0.288m/400=0.72mm（L=0.144mbI40b=14.4cm,h=40cm）结论：不可以采用。3试算bI20工字钢（考虑每侧采用两根bI40做横梁）a、剪力验算：钢）（385][1.6310578.39250000578.3925242AMPaMPamNcmtAP--6-满足要求b、弯曲应力验算：MPaMPammWMAN235][1.2071441.63c250101144.0102510578.392500003644满足要求c、刚度验算mmmmtEIPlfA72.0047.0102500101.2310144.0253811433悬臂构件计算跨度取实际长度2倍，L=0.144*2=0.288m,0.288m/400=0.72mm（L=0.144mbI40b=14.4cm,h=40cm）结论：可以采用。4试算aI25工字钢（考虑每侧采用两根bI40做横梁）d、剪力验算：钢）（385][5.5110541.482500005150285310541.48250000541.48252242AMPaMPaPamNcmtAP满足要求e、弯曲应力验算：MPaMPammWMAN235][1.1416.895.51c402101144.010255.51364满足要求f、刚度验算mmmmtEIPlfA72.0024.0105020101.2310144.0253811433悬臂构件计算跨度取实际长度2倍，L=0.144*2=0.288m,0.288m/400=0.72mm（L=0.144mbI40b=14.4cm,h=40cm）结论：可以采用。--7-4试算轨型为38kg/m普通碳素轨U74（考虑每侧采用两根bI40做横梁）a、剪力验算：）（74147][5.50105.4925000050505051105.492500005.49252242UMPaMPaPamNcmtAPU74的允许剪应力估算为0.36倍屈服强度取值为：147Mpa满足要求b、弯曲应力验算：MPaMPammWMAN410][7.2512.2015.50c9.178101144.010255.50364屈服满足要求c、刚度验算mmmmmtEIPlfA72.0098.010098.01041204101.2310144.02533811433悬臂构件计算跨度取实际长度2倍，L=0.144*2=0.288m,0.288m/400=0.72mm--8-结论：可以采用。实际施工过程中，两根串杠按照盖梁横坡不等高埋设。三、钢盒子底砼应力验算一处受集中力P1=2P=2×25=50t,钢盒子与砼接触面积取0.116×3=0.128m2,MpaMpaNmtAP8.26][43.1.348m01050348.05042(C40砼)满足要求--9-四、工字梁受力验算（I40a尺寸及参数：h=400mm,b=142mm,Ix=21700cm4,wx=1090cm3,理论重量=67.598（kg/m））（I36a尺寸及参数：h=360mm,b=136mm,Ix=15800cm4,wx=875cm3,理论重量=60.037（kg/m））（I50a尺寸及参数：h=500mm,b=160mm,Ix=46500cm4,wx=1860cm3,理论重量=93.654（kg/m））1）弯曲应力计算方法1（较精确计算）每次盖梁施工，采用4根aI40工字梁:M1（悬臂全截面段）=0.5×1.7×3×2.5×(0.5+0.058+0.25)=6.375×0.808=5.151t-mM2（悬臂渐变段）=（0.9+1.7）/2×2.425×3×2.5×(0.5+0.058+0.5+1.09)=23.64×2.148=50.78t-my2=(2.425×(1.7+2×0.9))/3×(1.7+0.9)=1.09m--10-M3（挡块）=0.5×0.56×3×2.5×(0.5+0.058+2.925-0.28)=2.1×3.203=6.726t-mM4（垫石）=0.8×0.8×2×0.175×2.5×(0.5+0.058+2.025)=0.56×2.583=1.446t-mM5（模板）=全截面段+悬臂全截面段+悬臂渐变段+挡块+垫石=0.09×（(1.7×2)×0.558×（0.558/2）+(1.7×2+3)×0.5×(0.5+0.058+0.5/2)+（（0.9+1.7）/2×2.425×2+2.554×3）×(0.5+0.058+1.09+0.5)+(0.5×0.56+0.5×3)×2×(0.5+0.058+2.925-0.28)+0.8×0.175×4×2×(0.5+0.058+2.025)）=0.09×（0.529+2.586+30.001+11.402+2.893）=0.09×47.411=4.267t-mM6（施工人员，施工料具荷载）：0.3t×2.925×(2.925/2+0.5+0.058)=0.878×2.02=1.773t-mM7（砼倾倒与振捣荷载）：1.2t×2.925×(2.925/2+0.5+0.058)=3.51×2.02=7.092t-m∑M=5.151+50.78+6.726+1.446+4.267+1.773+7.092=77.235t-m①σ=M/W=772350/(875×4×10-6)=220671428.6pa=220.7Mpa＜235Mpa(结论：使用4根36a工字梁可满足施工荷载要求)②σ=M/W=772350/(1090×4×10-6)=177144495pa=177Mpa＜235Mpa(结论：使用4根40a工字梁可满足施工荷载要求)③σ=M/W=772350/(1860×2×10-6)=207620967.7pa=207.6Mpa＜235Mpa(结论：使用2根50a工字梁可满足施工荷载要求)2）弯曲应力计算方法2（近似计算）--11-q=1.7×3×2.5=12.75tL=5.3mCA=BD=3.525m1、悬臂段AC=BC段：）（aIMPaWMmqlM456225.1381041430792134N.7921342525.312750023）挠度计算①取用4根I45a当)2(83laEIlqaffdc=)384.5)558.0925.2(2(10432200101.28384.5)558.0925.2(1275008113=0.0134×2.6469=0.035mm＜13.46mmmmmL46.13400384.5400当x=mla175.62384.5)558.0925.2(2--12-8112222min10432200101.216384.5)558.0925