表3.9梁的斜截面受剪承载力配筋计算表 梁斜截面受剪承载力配筋计算 层次 截面 A-B左 4 B右-C左 C右-D A-B左 3 B右-C左 C右-D A-B左 2 B右-C左 C右-D A-B左 1 B右-C左 C右-D 剪力(KN) 0.25?cfcbh0 AsvV?0.7ftbh0 实际配筋 ?s1.25ffvh0﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 ﹤0 实际nAsv s127.323 894.644>V 7.388 894.644>V 127.323 894.644>V 138.554 894.644>V 11.952 894.644>V 138.554 894.644>V 143.797 894.644>V 17.272 894.644>V 143.797 894.644>V 149.609 894.644>V 24.272 894.644>V 149.609 894.644>V 四肢 Ф8@200 0.973
3.5.1.3 挠度及裂缝的验算: 1.挠度的计算
以4层AB跨梁为例说明计算过程 (1)荷载的计算
梁左所承受的弯矩(标准值):
MgK?38.89KNm,MqK?3.55KNm,MWK?4.99KNm 梁内所承受的弯矩(标准值):
MgK?180.65KNm,MqK?11.8KNm,MWK?0.13KNm 梁右所承受的弯矩(标准值):
MgK?110.87KNm,MqK?7.90KNm,MWK?5.21KNm
屋面活荷载的准永久值系数?q?0,风荷载的准永久值系数?w?0,楼面活荷载的准永久值系数?q?0.5,风荷载的准永久值系数?w?0。
梁左:MK?38.89?3.55?4.99?47.43KNm Mq?38.89?0?0?38.89KNm
梁内:MK?180.65?11.8?0.13?192.58KNm Mq?180.65?0?0?180.65KNm 梁右:MK?110.87?7.90?5.21?123.98KNm Mq?110.87?0?0?110.87KNm (2)计算相关系数
梁左:?E??EsAs200?741.1??0.020
Ecbh030?350?715 ?te?As74.11??0.00 6Ate0.5?35?0750 ?skMK47.430?106???10N3/mm2 ?h0As0.87?71?574.11ftk?1.1?0.65?2.01??1.04﹤0.2 取??0.2
0.006?103 ??1.1?0.65?te?sk h'f?140mm<0.2ho=143mm,取h'f?140mm Bs?2EsAsh01.15??0.2?6?E?1?3.5?'f200?741.1?7152?103??1.38?1014Nmm2 1.15?0.2?0.2?6?0.020
Bl?MK47.43Bs??1.38?1014Mq???1??MK38.39??2?1??47.43
?7.63?1013Nmm2同样求得梁内: ?E??EsAs200?1137.4 ??0.030
Ecbh030?350?715As113.47??0.00 9Ate0.5?35?0750 ?te? ?skMK192.58?106???27N2/mm2 ?h0As0.87?71?5113.47ftk?1.1?0.65?2.01?0.57
0.009?272 ??1.1?0.65
?te?sk h'f?140mm<0.2ho=143mm,取h'f?140mm ?'f?b?'f?bh'fbh0???2825?350??140?1.4
350?715 Bs?2EsAsh01.15??0.2?6?E?1?3.5?'f?1.31?1014Nmm2
B?MKBs?6.75?1013Nmm2
Mq???1??MKEsAs200?942.6??0.025
Ecbh030?350?715梁右:?E?? ?te?As94.26??0.00 8Ate0.5?35?0750MK?21N1/mm2 ?h0Asftk?1.1?0.65?2.01?0.28
0.008?211 ?sk? ??1.1?0.65?te?sk h'f?140mm<0.2ho=143mm,取h'f?140mm Bs?2EsAsh01.15??0.2?6?E?1?3.5?'f?1.43?1014Nmm2
B?由于
(3)挠度验算
MKBs?7.37?1013Nmm2
Mq???1??MKBlB?2,r?2,可取跨中刚度B计算。 BB由结构力学知识求得S=0.102,
2MKl0192.58?106?87002?0.102??22.096mm 得:f?SB6.75?1013查表得:
fliml0?1200,故
fl0?22.0968700?11394﹤200 满足要求。
2.验算最大裂缝宽度(以跨中计算为例)
梁内: ?te?0.009 ﹤0.01,取?te?0.01
??0.57 , ?sk?272N/mm2 , C=25mm ,deq?19.050mm ,?cr?2.1
deq?272?19.050???wmax??cr?1.9c?0.08?2.1?0.57?1.9?25?0.08???5?得:Es??0.012?10?? te???0.35174mm?wlim?0.4mm?sk?满足要求。 其他验算见下表:
表3.10梁的挠度及裂缝计算表(下页)