1、2楼板设计2.1楼面结构信息及单元划分:结构板厚取100,并在和、段设L1、L2、L3,截面均为bh=240300对楼面做一定划分并将楼梯间处做一些调整,选代表性部分作为计算单元.做法如图1:2.2楼面荷载计算:表1荷载种类标准值 KN/备注恒荷载硬木地板 0.4按楼板结构 自上向下列15厚水泥砂浆0.01520=0.310厚水泥砂浆找平0.0120=0.2100厚现浇板0.125=2.5天棚粉刷0.18小 计0.4+0.3+0.2+2.5+0.18=3.58活 载 2.0所有房间恒荷载分项系数g=1.2 活载分项系数q=1.4楼面恒载设计值:g=1.23.58=4.3 KN/楼面活载设计值:
2、q=1.42.0=2.8 KN/2.3标准层设计: 按弹性理论计算板,根据连续多跨双向板的实用计算法计算跨中最大正弯矩为内支座固支时g+q/2和内支座铰支时q/2算出的弯矩和。支座最大负弯矩为内支座固支时g+q求得(取相邻板算得的负弯矩绝对值的较大值)。g+q=4.3+2.8=7.1 KN/g+q/2=4.3+1.4=5.7 KN/q/2=1.4 KN/2.3.1板计算跨度:内跨 Lo=Lc Lc为轴线距离边跨 Lo=Ln+ Ln净跨,为梁宽2.3.2板弯矩计算:考虑泊松比Vc=0.2 由于房间大小的差异,某些双向板同方向相邻跨度相差较大,因此对算得的弯矩应作一些调整。A区格板:Lx=3.6-
3、0.12-0.12+0.24=3.6m Ly=4.2m Lx/Ly=0.86 mx=(0.0266+0.20.0231)(g+q/2)Lx+(0.0496+0.20.035)(q/2)Lx=0.03125.73.6+0.05661.4x3.6=3.341 KNZm/mmy=(0.0231+0.2x0.0266)x5.7x3.6+(0.035+0.2x0.0496)x1.4x3.6 =2.1+0.82=2.92 KNZm/mmxM=-0.07x(g+q)Lx=-0.07x7.1x3.6=-6.44 KNZm/mmyM=-0.067x7.1x3.6=-6.24 KNZm/mB区格板:Lx=3.6m
4、 Ly=4.2m Lx/Ly=0.86mx=(0.0322+0.2x0.0231)x5.7x3.6+(0.0496+0.2x0.035)x1.4x3.6 =2.72+1.03=3.75 KNZm/mmy=(0.0231+0.2x0.0322)x5.7x3.6+(0.035+0.2x0.0496)x1.4x3.6 =2.18+0.82=3.00 KNZm/mmxM=-0.0818x7.1x3.6=-7.53 KNZm/mmyM=-0.073x7.1x3.6=-6.72 KNZm/mC区格板:Lx=3.5m Ly=4.2m Lx/Ly=0.83mx=(0.0341+0.2x0.0225)x5.7x
5、3.5+(0.0528+0.2x0.0342)x1.4x3.5=2.69+1.02=3.71 KNZm/mmy=(0.0225+0.2x0.0341)x5.7x3.5+(0.0342+0.2x0.0528)x1.4x3.5=2.05+0.77=2.82 KNZm/mmxM=-0.0851x7.1x3.5=-7.4 KNZm/mmyM=-0.0739x7.1x3.5=-6.43 KNZm/mD区格板:由于D区格板在Y方向与相邻板F(G)的跨度较大,因此在按g+q/2算得的跨中弯矩曾的10%,q/2算得的跨中弯矩减小5%。 Lx=4.8m Ly=4.2m Ly/Lx=0.875mx=(0.0161
6、+0.2x0.0234)x5.7x4.2+(0.0353+0.2x0.0481)x1.4x4.2 =2.1+1.1=3.2 KNZm/mmy=(0.0234+0.2x0.0161)x5.7x4.2x1.1+(0.0481+0.2x0.0353)x1.4x4.2x0.95=2.94+1.29=4.23 KNZm/mmxM=-0.0546x7.1x4.2=-6.84 KNZm/mmyM=-0.0739x7.1x4.2=-7.60 KNZm/mE区格板:同D区格板,对X向跨中弯矩进行调整 Lx=5.1m Ly=3.3m Ly/Lx=0.65mx=(0.0183+0.2x0.0465)x5.7x3.3
7、x1.1+(0.0271+0.2x0.075)x1.4x3.3x0.95=1.88+0.61=2.49 KNZm/mmy=(0.0465+0.2x0.0183)x5.7x3.3+(0.075+0.2x0.0271)x1.4x3.3 =3.11+1.25=4.34 KNZm/mmxM=-0.0777x7.1x3.3=-6.01 KNZm/mmyM=-0.1045x7.1x3.3=-8.08 KNZm/mF区格板:不考虑实际周边板对跨中弯矩的影响 Lx=2.4m Ly=2.1m Ly/Lx=0.875mx=(0.0233+0.2x0.0256)x5.7x2.1+(0.0353+0.2x0.0481
8、)x1.4x2.1=0.71+0.28=0.99 KNZm/mmy=(0.0256+0.2x0.0233)x5.7x2.1+(0.0481+0.2x0.0353)x1.4x2.1 =0.076+0.34=1.1mxM=-0.067x7.1x2.1=-2.1 KNZm/mmyM=-0.0682x7.1x2.1=-2.1 KNZm/mG区格板: Lx=Ly=2.1m Lx/Ly=1mx=(0.0231+0.2x0.018)x5.7x2.1+(0.0368+0.2x0.0368)x1.4x2.1=0.67+0.27=0.94 KNZm/mmy=(0.018+0.2x0.0231)x5.7x2.1+(
9、0.0368+0.2x0.0368)x1.4x2.1 =0.57+0.27=0.84 KNZm/mmxM=-0.06x7.1x2.1=-1.88 KNZm/mmyM=-0.055x7.1x2.1=-1.72 KNZm/mH区格板:对X向跨中弯矩进行调整 Lx=4.5m Ly=3.3m Ly/Lx=0.73mx=(0.0202+0.2x0.041)x5.7x3.3x1.1+(0.0309+0.2x0.0645)x1.4x3.3x0.95=1.94+0.63=2.57 KNZm/mmy=(0.041+0.2x0.0202)x5.7x3.3+(0.0645+0.2x+0.0309)x1.4x3.3
10、=2.8+1.08=3.88 KNZm/mmxM=-0.0764x7.1x3.3=-5.91 KNZm/mmyM=-0.096x7.1x3.3=-7.4 KNZm/mI区格板:将Y向跨中弯矩增大10% Lx=3.6m Ly=4.2m Lx/Ly=0.86mx=(0.0241+0.2x0.0158)x5.7x3.6+(0.0496+0.2x0.035)x1.4x3.6=2.01+1.03=3.04 KNZm/mmy=(0.0158+0.2x0.0241)x5.7x3.6x1.1+(0.353+0.2x0.0496)x1.4x3.6=1.68+0.82=2.5 KNZm/mmxM=-0.0618x
11、7.1x3.6=-5.69 KNZm/mmyM=-0.0549x7.1x3.6=-5.05 KNZm/mJ区格板: Lx=3.6m Ly=4.2m Lx/Ly=0.086mx=(0.0289+0.2x0.0157)x5.7x3.6+(0.0496+0.2x0.035)x1.4x3.6=2.37+1.03=3.40 KNZm/mmy=(0.0157+0.2x0.0289)x5.7x3.6+(0.035+0.2x0.0496)x1.4x3.6=1.59+0.82=2.41 KNZm/mmxM=-0.0687x7.1x3.6=-6.32 KNZm/mmyM=-0.0566x7.1x3.6=-5.21
12、 KNZm/m 其中mxy为板底跨中沿X(Y)向的最大正弯矩,mxMy为固定边沿X(Y)的支座负弯矩。2.3.3板截面设计: 因短跨方向的弯矩比长跨的大,故将短跨方向的钢筋放在长跨钢筋外侧。短跨跨中截面的有效高度ho1=h-20=100-20=80mm,长跨跨中截面有效ho2=h-30=100-30=70mm.2.3.4板配筋计算: 取内力臂系数s=0.95, As=m/(0.95ZfyZho),板采用C20混凝土、8钢筋。考虑实际施工中的缺陷及日后使用的要求,以理论值作为基础适当增大配筋。各板配筋计算结果及实际配筋见表2: 表2截 面 ho(mm)m(KNZm/m)As(mm/m)配筋实有A
13、s(mm/m)跨中A区格X向803.412098180279Y向702.922098180279B区格X向803.752348150335Y向703.02148180279C区格X向803.712328150335Y向702.822028180279D区格X向703.22298150335Y向804.232658150335E区格X向702.491788180279Y向804.342728180335F区格X向700.99718200251Y向801.1698200251截 面 ho(mm)m(KNZm/m)As(mm/m)配筋实有As(mm/m)跨中G区格X向700.94608200251Y
14、向800.84538200251H区格X向702.571848180279Y向703.882438150335I区格X向803.041908180279Y向702.501798180279J区格X向803.42138180279Y向702.412138180279支座A-E80-8.085068100503A-D80-6.844288100503D-E80-8.085068100503D-F80-7.64768100503D-C80-7.64768100503D-D80-6.844288110457D-G80-7.64768100503D-H80-7.64768100503D-I80-6.84
15、4288100503F-G80-2.11328200251C-B80-7.534718100503C-J80-7.4 4638100503I-H80-7.4 4638100503I-I80-5.693568110457I-J80-5.213268110457J-J80-6.32 3968110457E-F80-6.01 3768110457H-G80-5.91 3708110457A-B80-6.724218110457续表22.3.5楼面梁设计选L1作为计算构件,截面bxh=240x3002.3.5.1受力分析及内力计算根据双向板传力方式,可知L1除承受自重外还承受由A区板传来的梯形分布荷载
16、和D区传来的三角形分布荷载. 如图2: L1与圈梁整浇,故将L1两端作为固支(1)、由梯形分布引起的支座弯矩:将梯形分布荷载转化为等效均布荷载qe,它是根据支座弯矩相等的条件求出的 qM=0.5xql=0.5x7.1x3.6=12.78 KN/mqe=(1-2+)qM=(1-2x0.43+0.43)x12.78=9.1 KN/mMM支=-(1/12)xqexl=-(1/12)x9.1x4.2=-13.4 KNZm 根据算得的支座弯矩和梁上荷载分布的实际情况,由平衡条件计算梁的跨中弯矩和支座剪力。见图3 由平衡条件求得 MM中=7.87 KNZm QM支=15.34 KN(2)、由三角形分布引起
17、的支座弯矩: 将三角形分布荷载转化为等效均布荷载 qM=0.5xqxl=0.5x7.1x4.2=14.91 KN/m qe=(5/8)qM=9.32 KN/mMMM支=-(1/12)xqexl=-(1/12)x9.32x4.2=-13.7 KN/m按荷载分布实际情况计算梁跨中弯矩和支座剪力 由平衡条件求得 MMM中=8.23 KNZm QMM支=15.66 KN(3)、梁自重产生的荷载 q=25x0.24x(0.3-0.1)=1.2 KN/m MMMM支=-(1/12)ql=-(1/12)x1.2x4.2=-1.76 KNZm MMMM中=(1/24)ql=(1/24)x1.2x4.2=0.8
18、8 KNZm QMMM支=0.5x1.2x4.2=2.52 KNM中=M中=7.87+8.23+0.88=16.98 KNZmM支=M支=-13.4-13.7-1.76=-28.86 KNZmQ支=Q支=15.34+15.66+2.52=33.52 KNZm考虑内力重分布对支座弯矩进行调幅将支座弯矩减小20%,相应将跨中弯矩增大30%。M支=-28.86x0.8=-23 KNZm M中=16.98x1.3=22.1 KNZm2.3.5.2配筋计算: (1)跨中弯矩配筋:梁采用C20混凝土,HRB335钢筋。梁按T型截面计算 1=1.0 fc=9.6N/mm ft=1.1N/mm fy=300N
19、/mm ho=300-35=265mm bMf=1000mm1fcbMfhMf(ho-0.5hMf)=1.0x9.6x1000x100x(265-0.5x100)=206.4 KNZm 22.1 KNZm 属于第一种类型的T型梁s=M/(1fcbMfho)=22.1x106/(1.0x9.6x1000x265)=0.033=0.55s=0.5x(1+)=0.98As=M/(fysho)=22.1x106/(300x0.98x265)=284 mm选用312 实有As=339 mm =339/(240x265)=0.53%45xft/fy=45x1.1/300=0.165% 满足最小配箍率(2)
20、支座负弯矩配筋:s=M/(1fcbho)=23x106/(1.0x9.6x240x265)=0.14=0.1533.52 KN截面符合要求0.7ftbho=0.7x1.1x240x265=48.9733.52 KN 只需构造配筋,选配8150sv=2x50.3/(240x150)=0.28%svmin=0.24xft/fyv=0.24x1.1x210=0.126%L2、L3配筋方式同L12.4一层设计:一层荷载、板的布置方式、板配筋同标准层。各梁截面改为bxh=370x300。 一层L1配筋计算:梁自重产生的线荷载:q=25x0.37x(0.3-0.1)=1.85 KN/mMMMM支=-(1/
21、12)ql=-(1/12)x1.85x4.2=-2.72 KNZm MMMM中=(1/24)ql=(1/24)x1.85x4.2=1.36 KNZmQMMM支=0.5x1.85x4.2=3.89 KN经调幅后,梁各内力:M中=22.7 KNZm M支=-23.8 KNZm Q支=34.89 KN由于荷载增加不大且考虑T型梁受压翼缘增大等因素,可按标准层L1配筋。 2.4.2板内力及配筋计算:Lx=3.5m Ly=4.2m Lx/Ly=0.83 mx=(0.0301+0.2x0.0152)x8.0x3.5+(0.0528+0.2x0.0342)x1.4x3.5 =3.24+1.02=4.27 K
22、NZm/m my=(0.0152+0.2x0.0301)x8.0x3.5+(0.0342+0.2x0.0528)x1.4x3.5 =2.08+0.77=2.85 KNZm/m mxM=-0.0705x9.4x3.5=-8.11 KNZm/m myM=-0.0568x9.4x3.5=-6.54 KNZm/m X向跨中As=m/(0.95ZfyZho)4.27x106/(0.95x210x80)=267 mm 配8150 Y向跨中As=2.85x106/(0.95x210x70)=204 mm 配8180 C-B支座 As=8.11x106/(0.95x210x80)=508 mm 配8100C-
23、D支座 As=7.6x106/(0.95x210x80)=476 mm 配8100 2.4.3楼面洞口计算:在洞口边设置暗梁AL1 bxh=550x100 采用HRB335钢筋。将相邻板上一半荷载全传给暗梁,则暗梁所受均布线荷载P=0.5x3.5x7.1=12.43KN/m 取暗梁的计算跨度lo=3.0m 跨中弯矩M=0.1xPxlo=0.1x12.43x3=11.2 KNZm暗梁采用双筋截面配筋:ho=100-40=60mm aMs=20mm b=550mm 取b=0.55Mu2=1fcbhob(1-0.5b)=1.0x9.6x550x60x0.55x(1-0.5x0.55)=7.58 kN
24、ZmAMs=(M-Mu2)/fMy(ho-aMs)=3.62x106/(300x40)=302 mmAs=b1fcbho/fy+AMsfMy/fy=0.55x1.0x9.6x550x60/300+302=882.8mm受拉钢筋配614As=923mm 受压钢筋配410 As=314mm 箍筋配6150夹层其它部分配筋同标准层。楼梯间板底钢筋X向由C区通长配置,Y向配8180考虑开洞影响 将F、G区格在Y向加大板底配筋为81803斜屋面板计算3.1屋面结构信息及单元划分:结构板厚取120mm,屋面倾角tg=0.5 cos=0.894 ,在、段设梁LM2、LM3,截面均为bxh=240x300。
25、对屋面板进行一定的划分,选代表性部分作为计算单元。具体做法如图5:3.2荷载计算:将屋面斜向均布荷载折算成水平均布荷载 表4荷载种类标准值 KN/m备注恒荷载水泥瓦0.5/0.894=0.56不上人屋面活载取0.6KN/m平铺油毡一层0.05/0.894=0.0620厚找平层0.02x20/0.894=0.45120厚现浇板0.12x25/0.894=3.36天棚粉刷0.16/0.894=0.18小计 0.56+0.06+0.45+3.36+0.18=4.61活载0.6/0.894=0.7 恒荷载分项系数g=1.2 活载分项系数q=1.4 屋面恒载设计值:g=1.2x4.61=5.53 KN/
26、m 屋面活载设计值:q=1.4x0.7=1.0 KN/m 按弹性理论计算板配筋(暂不考虑老虎窗及屋顶窗对配筋的影响,即按整板计算) 根据连续多跨双向板的实用计算法计算。 g+q=5.53+1.0=6.53 KN/m g+q/2=5.53+0.5=6.03 KN/m q/2=0.5 KN/m3.3计算跨度:内跨:Lo=Lc Lc为轴线距离边跨:Lo=Ln+b Ln为净跨,b为梁宽3.4板弯矩计算:考虑泊松比Vc=0.2。由于屋面板的活荷载较小,因此不对弯矩进行调整。A 区格板:Lx=8.4m Ly=4.2m Ly/Lx=0.5 mx=(0.0089+0.2x0.0409)x6.03x4.2+(0
27、.0174+0.2x0.0965)x0.5x4.2 =1.82+0.32=2.14 KNZm/m my=(0.0409+0.2x0.0089)x6.03x4.2+(0.0965+0.2x0.0174)x0.5x4.2 =4.54+0.88=5.42 KNZm/m mxM=-0.569x6.53x4.2=-6.55 KNZm/m myM=-0.0836x6.53x4.2=-9.63 KNZm/mB 区格板:Lx=3.6m Ly=4.2m Lx/Ly=0.86 mx=(0.0368+0.2x0.0347)x6.03x3.6+(0.0496+0.2x0.035)x0.5x3.6 =3.42+0.37
28、=3.79 KNZm/m my=(0.0347+0.2x0.0368)x6.03x3.6+(0.035+0.2x0.0496)x0.5x3.6 =3.29+0.29=3.58 KNZm/m mxM=0 myM=-0.0961x6.53x3.6=-8.13 KNZm/mC 区格板:Lx=5.1m Ly=3.3m Ly/Lx=0.65 mx=(0.0183+0.2x0.0465)x6.03x3.3+(0.0271+0.2x0.075)x0.5x3.3 =1.81+0.23=2.04 KNZm/m my=(0.0465+0.2x0.0183)x6.03x3.3+(0.075+0.2x0.0271)x
29、0.5x3.3 =3.29+0.44=3.73 mxM=-0.0777x6.53x3.3=-5.53 KNZm/m myM=-0.1045x6.53x3.3=-7.43 KNZm/mD 区格板:Lx=2.4m Ly=2.1m Ly/Lx=0.875 mx=(0.0233+0.2x0.0256)x6.03x2.1+(0.0353+0.2x0.0481)x0.5x2.1 =0.76+0.1=0.86 KNZm/m my=(0.0256+0.2x0.0233)x6.03x2.1+(0.0481+0.2x0.0353)x0.5x2.1 =0.8+0.12=0.92 KNZm/m mxM=-0.067x
30、6.53x2.1=-1.93 KNZm/m myM=-0.0682x6.53x2.1=-1.96 KNZm/mE 区格板:Lx=2.1m Ly=2.1m Lx/Ly=1 mx=(0.0231+0.2x0.018)x6.03x2.1+(0.0368+0.2x0.0368)x0.5x2.1 =0.71+0.1=0.81 KNZm/m my=(0.018+0.2x0.0231)x6.03x2.1+(0.0368+0.2x0.0368)x0.5x2.1 =0.6+0.1=0.7 KNZm/m mxM=-0.06x6.53x2.1=-1.73 KNZm/m myM=-0.055x6.53x2.1=-1.
31、58 KNZm/mF 区格板:Lx=2.6m Ly=5.7m Lx/Ly=0.45 取0.5 将算得的X向跨中弯矩增大10% mx=(0.0888+0.2x0.0249)x6.03x2.6x1.1+(0.0965+0.2x0.0174)x0.5x2.6 =4.21+0.34=4.55 KNZm/m my=(0.0249+0.2x0.0888)x6.03x2.6+(0.0174+0.2x0.0965)x0.5x2.6 =1.74+0.12=1.86 KNZm/m myM=-0.1215x6.53x2.6=-5.36 KNZm/mG 区格板:Lx=8.4m Ly=4.2m Ly/Lx=0.5 mx
32、=(0.0038+0.2x0.04)x6.03x4.2+(0.0174+0.2x0.0965)x0.5x4.2=1.26+0.32=1.58 KNZm/m my=(0.04+0.2x0.0038)x6.03x4.2+(0.0965+0.2x0.0174)x0.5x4.2 =4.34+0.88=5.22 KNZm/m mxM=-0.057x6.53x4.2=-6.57 KNZm/m myM=-0.0829x6.53x4.2=-9.55 KNZm/mH 区格板:Lx=3.6m Ly=4.2m Lx/Ly=0.86 mx=(0.0322+0.2x0.0231)x6.03x3.6+(0.0496+0.
33、2x0.035)x0.5x3.6 =2.88+0.37=3.25 KNZm/m my=(0.0231+0.2x0.0322)x6.03x3.6+(0.035+0.2x0.0496)x0.5x3.5 =2.31+0.29=2.6 KNZm/m mxM=-0.0818x6.53x3.6=-6.92 KNZm/m myM=-0.073x6.53x3.6=-6.18 KNZm/mI 区格板:Lx=4.5m Ly=3.3m Ly/Lx=0.73 mx=(0.0202+0.2x0.041)x6.03x3.3+(0.0309+0.2x0.0645)x0.5x3.3 =1.86+0.24=2.1 KNZm/m
34、 my=(0.041+0.2x0.0202)x6.03x3.3+(0.0645+0.2x0.0309)x0.5x3.3 =2.96+0.38=3.34 KNZm/m mxM=-0.0764x6.53x3.3=-5.43 KNZm/m myM=-0.096x6.53x3.3=-6.83 KNZm/m截 面ho(mm)M(KNZm/m)As(mm/m)配筋实有As(mm/m)跨中A区格X向902.141198150335Y向1005.422718150335B区格X向1003.791908150335Y向903.581998150335C区格X向902.041148150335Y向1003.731
35、878150335D区格X向900.86488150335Y向1000.92468150335E区格X向1000.81418150335Y向900.7398150335F区格X向1004.552288150335Y向901.861038150335G区格X向901.58888150335Y向1005.222628150335H区格X向1003.251638150335Y向902.614581503353.5板截面设计 短跨跨中截面的有效高度ho1=120-20=100mm,长跨跨中截面有效度ho2=120-30=90mm考虑屋面板受环境因素影响较大,防止其在正常使用阶段产生较大裂缝。屋面板上层
36、钢筋不宜断开,若断开需另加温度钢筋。3.6板配筋计算:取内力臂系数s=0.95, As=m/(0.95ZfyZho),板采用C20混凝土、8钢筋。各板的配筋结果及实际配筋见下表: 表5 续表5截 面ho(mm)M(KNZm/m)As(mm/m)配筋实有As(mm/m)跨中I区格X向902.11178150335Y向1003.341678150335支座A-B100-9.634838100503A-C100-9.634838100503A-D100-9.634838100503A、G-F100-9.634838100503A-G100-6.573298100503G-E100-9.5547881
37、00503G-I100-9.554788100503G-H100-9.554788100503G-G100-6.573298100503H-H100-6.923468100503C-D100-5.53277.198100503D-E100-1.9396.748100503E-I100-5.4327281005033.7屋面梁设计:选LM2作为配筋计算构件:(屋面梁均按LM2方式配筋)截面尺寸bxh=240x300 采用C20混凝土,HRB335钢筋将梁两相邻板各一半荷载视为全由LM2承担,则梁承受的均布线荷载P=0.5x2.1x6.53+0.5x4.2x6.53+25x0.24x(0.3-0.
38、12) =6.86+13.71+1.2=21.77 KN/m支座弯矩M支=-(1/12)xPxL=-21.77x2.4/12=-10.45 KNZm考虑内力重分布对支座弯矩进行调幅:M支=0.8x10.45=8.36 KNZm根据平衡条件:得跨中弯矩M中=7.31 KNZm(1)、跨中配筋: s=M/(1fcbho)=7.31x106/(1.0x9.6x240x265)=0.045s=0.5x(1+)=0.98As=M/(fysho)=7.31x106/(300x0.98x265)=93.8 mm选用212 As=226 mm=226/(240x265)=0.35%45xft/fy=45x1.1/300=0.214% 满足最小配筋率(2)、支座配筋:s=M/(1fcbho)=8.36x106/(1.0x9.6x240x265)=0.052s=0.5x(1+)=0.97As=M/(fysho)=8.36x106/(300x0.97x265)=108 mm选用212 As=226 mm(3)、斜截面承载力验算:剪力最大值V=2.4x21.77x0.5=26 KN0.25cfcbho=0.25x1.0x9.6x2