工况一柱脚反力为最不利荷载:N=2505kN,V=707 kN,M=51.9kN.m
每个锚筋锚固长度La =900mm(>35d),直径D=25mm,有效面积Ae =490.9mm2 采用Ⅱ级钢筋,fy=300MPa
按规范,锚筋总截面面积满足以下两式:
As?V?0.3NM?0.4Nz ?aravfy1.3arabfyzM?0.4Nz
0.4arabfyzAs?当M?0.4Nz时,取M?0.4Nz 其中:
ar 锚筋层数影响系数,>4层取0.85 ab 锚板弯曲变形的折减系数
t25ab?0.6?0.25?0.6?0.25??0.85
d25av 锚筋受剪承载力系数
av?(4?0.08d)fc14.3?(4?0.08?25)?0.437 fy300t =25mm
d = 25mm
z = 1200mm (外层锚筋中心线距离)
As?V?0.3NM?0.4Nz1150000?0.3?2969000???0?2327mm2
aravfy1.3arabfyz0.85?0.437?300实际值AS?490.9?16?7854mm2?2327mm2,满足要求。 计算埋件锚筋时,最不利荷载的取值
附墙最大反力:N1=44kN,V1 =182?382=42kN,M1=61kN·m N2=323kN,V12=2.62?1.22=3kN,M1=7kN·m
每个锚筋直径D=25mm,有效面积Ae =490.9mm2 采用Ⅱ级钢筋fy=310MPa,按规范取fy=300MPa 按规范,锚筋总截面面积满足以下两式:
As?VNM?? aravfy0.8abfy1.3arabfyzNM?
0.8abfy0.4arabfyzAs?ar 锚筋层数影响系数,>4层为0.85
ab 锚板弯曲变形的折减系数
t25ab?0.6?0.25?0.6?0.25??0.85
d25av 锚筋受剪承载力系数
av?(4?0.08d)fc14.3?(4?0.08?25)?0.437 fy300t=25mm
d=25mm z=600mm
对于N1=44kN,V1 =182?382=42kN,M1=61kN·m
VNM???377?216?361?954mm2 aravfy0.8abfy1.3arabfyzNM??216?1173?1389mm2
0.8abfy0.4arabfyz实际值AS?400.9?8?3207mm2?1389mm2
对于N2=323kN,V12=2.62?1.22=3kN,M1=7kN·m
VNM???27?1583?70?1680mm2 aravfy0.8abfy1.3arabfyzNM??1583?229?1812mm2
0.8abfy0.4arabfyz实际值AS?400.9?8?3207mm2?1812mm2
满足要求。
最不利荷载(锚筋计算除外):V=616kN,M=554kN.m 采用12根直径32的螺纹钢
每个锚筋直径D=32mm,有效面积Ae =804mm2 采用Ⅱ级钢筋fy=310MPa,按规范取fy=300MPa 按规范,锚筋总截面面积满足以下两式:
As?VNM?? aravfy0.8abfy1.3arabfyzNM?
0.8abfy0.4arabfyzAs?ar 锚筋层数影响系数,>4层为0.85 ab 锚板弯曲变形的折减系数
t25ab?0.6?0.25?0.6?0.25??0.80
d32av 锚筋受剪承载力系数
av?(4?0.08d)fc14.3?(4?0.08?32)?0.3144 fy300t=25mm
d=32mm z=600mm
VNM???6398?0?3482?9880mm2 aravfy0.8abfy1.3arabfyzNM??0?11317?11317mm2
0.8abfy0.4arabfyz实际值AS?804?16?12864mm2?11317mm2
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