资源描述
筏板基础及侧壁计算书
一、基本数据:
根据 xx 省 xx 护国房地产开发有限公司护国广场岩土工程勘察报告,本工程以③层圆 砾层为持力层,地基承载力特征值为 220KPa 。基础形式为筏板基础,混凝土强度等级
为 C 40 , fc
= 19.1N / mm2 ;受力钢筋均采用 HRB400 级,fy=360 N / mm2 ;根据地质
报告,地下水位取 − 1.700m 。
二、地基承载力修正及验算:
fa =
fak + ηbγ (b − 3) + ηd γ m (d − 0.5)
= 220 + 0.3 × 8 × (6 − 3) + 1.5 × 8 × (5.65 − 0.5)
= 289.0kN / m2
上部荷载作用下地基净反力(由地下室模型竖向导荷得)
f = 61.6kN / m2 <
f = 289.0kN / m2
a
地基承载力满足要求。
三、地下室侧壁配筋计算:
(1)双向板:
ly 5.175
l
① lx = 8.400m , ly = 5.175m , =
x
8.4
= 0.62
E土 = rhKa
= 8.0 × 5.175 × tan 2 45o = 41.4KN / m
E水 = rh = 10.0 × 3.475 = 34.75KN / m
E合 = 1.27E土 + 1.27E水 = 52.6 + 44.1 = 96.7KN / m
查静力计算手册,得:
2
M x max = 0.0072ql
2
= 0.0072 × 96.7 × 5.1752
2
= 18.6KN ·m
M y max = 0.0209ql
'
= 0.0209 × 96.7 × 5.175
2
= 54.1KN ·m
2
M x max
'
= −0.0354ql
2
= 0.0354 × 96.7 × 5.175
2
= −91.7KN ·m
M y = −0.0566ql
= −0.0566 × 96.7 × 5.175
= −146.6KN ·m
配筋计算:
取弯矩最大处进行计算。即取 M = 146.6kN ·m
1
混凝土强度等级为 C 40 , fc
= 19.1N / mm2 ; α
= 1.0 ;受力钢筋均采用
HRB400
级,fy=360 N / mm2 ; ξ
= 0.523 ; ρ
min
= 0.2% ;
b
相对受压区高度:
x = h0 (1 −
2
1 − 2M )
α1 fcbh0
= 310 × (1 −
1 − 2 × 146600000 )
1.0 ×19.1×1000 × 3102
= 25.8mm < xb = ξb h0 = 0.523 × 302 = 157.9mm
则
As =
α1 fcbx f y
= 1.0 ×19.1×1000 × 25.8
360
= 1368.8mm2
实际配筋:内外均φ16@150
A = 1340mm2
s
ly 5.175
l
② lx = 7.800m , ly = 5.175m , =
x
7.8
= 0.66
E土 = rhKa
= 8.0 × 5.175 × tan 2 45o = 41.4KN / m
E水 = rh = 10.0 × 3.475 = 34.75KN / m
E合 = 1.27E土 + 1.27E水 = 52.6 + 44.1 = 96.7KN / m
查静力计算手册,得:
2
M x max = 0.0081ql
= 0.0081× 96.7 × 5.1752
2
= 21.0KN ·m
2
M y max
M
'
x max
'
= 0 .0194 ql
= −0.0351ql 2
2
= 0 .01 × 96 .7 × 5 .175
= 0.0351× 96.7 × 5.1752
2
= 54 .1KN ·m
= −90.9KN ·m
M y = −0.0542ql
= −0.0542 × 96.7 × 5.175
= −140.4KN ·m
配筋计算:
取弯矩最大处进行计算。即取 M = 140.4kN ·m
1
混凝土强度等级为 C 40 , fc
= 19.1N / mm2 ; α
= 1.0 ;受力钢筋均采用
HRB400
级,fy=360 N / mm2 ; ξ
= 0.523 ; ρ
min
= 0.2% ;
b
相对受压区高度:
x = h0 (1 −
2
1 − 2M )
α1 fcbh0
= 310 × (1 −
1 − 2 × 140400000 )
1.0 ×19.1×1000 × 3102
= 24.7mm < xb = ξb h0 = 0.523 × 302 = 157.9mm
则
As =
α1 fcbx f y
= 1.0 × 19.1×1000 × 24.7
s
360
= 1310mm2
实际配筋:内外均φ16@150
(2)E~F 轴间板:
A = 1340mm2
lx
① lx = 4.000m , ly = 5.175m ,
ly
= 4.000
5.175
= 0.77
E土 = rhKa
= 8.0 × 5.175 × tan 2 45o = 41.4KN / m
E水 = rh = 10.0 × 3.475 = 34.75KN / m
E合 = 1.27E土 + 1.27E水 = 52.6 + 44.1 = 96.7KN / m
查静力计算手册,得:
2
M x max = 0.0155ql
2
= 0.0155 × 96.7 × 5.1752
2
= 40.1KN ·m
M y max = 0.0094ql
'
= 0.0094 × 96.7 × 5.175
2
= 24.3KN ·m
2
M x max
'
= −0.0386ql
2
= 0.0386 × 96.7 × 5.175
2
= −100.0KN ·m
M y = −0.0394ql
= −0.0394 × 96.7 × 5.175
= −102.0KN ·m
配筋计算:
取弯矩最大处进行计算。即取 M = 102.0kN ·m
混凝土强度等级为 C 40 , fc
= 19.1N / mm2 ; α
= 1.0 ;受力钢筋均采用
1
HRB400
级,fy=360 N / mm2 ; ξ
= 0.523 ; ρ
min
= 0.2% ;
b
相对受压区高度:
x = h0 (1 −
2
1 − 2M )
α1 fcbh0
= 310 × (1 −
1 − 2 × 102000000 )
1.0 ×19.1× 1000 × 3102
= 17.7mm < xb = ξb h0 = 0.523 × 302 = 157.9mm
则
As =
α1 fcbx f y
= 1.0 × 19.1×1000 × 17.7
360
= 939mm2
实际配筋:内外均φ16@150
A = 1340mm2
s
三、筏板基础计算:
⑴ 冲切临界截面周长及极限惯性矩计算:
1、 内柱:
c1 = hc + h0 = 800 + 890 = 1690mm c2 = bc + h0 = 800 + 890 = 1690mm
c = c1 = 1690 = 845mm
AB 2 2
um = 2c1 + 2c2 = 2 ×1690 + 2 ×1690 = 6760mm
3
I = c1h0
c 3h c h c 2
+ 1 0 + 2 0 1
s 6 6 6
3 3 2
= 1690 × 890
+ 1690
× 890 + 1690 × 890 ×1690
= 16305.2 ×108 mm4
6 6 6
2、边柱:
c1 = hc
+ h0
2
= 800 + 890 = 1245mm
2
c2 = bc + h0 = 800 + 890 = 1690mm
2
x = c1 =
12452
= 370.8mm
2c1 + c2
2 ×1245 + 1690
cAB = c1 − x = 1245 − 370.8 = 874.2mm
um = 2c1 + c2 = 2 ×1245 + 1690 = 4180mm
3
I = c1h0
c 3h c 2
+ 1 0 + 2h c ( 1 − x)2 + c h x
s 6 6
3
0 1 2 2 0
3
= 1245 × 890
+ 1245
× 890 + 2 × 890 ×1245 × (1245 − 370.8)2 + 1690 × 890 × 370.82
6 6 2
= 7797.3 ×108 mm3
3、角柱:
c1 = hc
+ h0
2
= 800 + 890 = 1245mm
2
c = b
+ h0 = 800 + 890 = 1245mm
2 c 2
2
x = c1 =
2
12452
= 415mm
2c1 + c2
2 × 1245 + 1245
cAB = c1 − x = 1245 − 415 = 830mm um = c1 + c2 = 2 × 1245 = 2490mm
3
I = c1h0
+ c1 h0 + h c ( c1 − x)2 + c h x2
3
s 12 12
3
0 1 2 2 0
3
= 1245 × 890
+ 1245
× 890 + 890 ×1245 × (1245 − 415)2 + 1245 × 890 × 4152
12 12 2
= 4548.1×108 mm3
⑵抗冲切及抗剪承载力验算
1、 内柱:取柱轴力最大处,即 9 轴/F 轴: 由地下室 PKPM 竖向导荷,知: Fl = 5206kN
①抗冲切承载力验算: 由上述计算知道
um = 6760mm ; c1 = 1690mm ; c2 = 1690mm ; cAB = 845mm
s
I = 16305.2 ×108 mm4
考虑作用在冲切临界截面重心上的不平衡弯矩较小,本计算予以忽略。即: M unb = 0
h
距柱边 0 处冲切临界截面的最大剪应力τ :
2
τ = Fl
+ α s M unbcAB =
5206
max
+ =
kN m2
max
um h0 I s
6.76 × 0.89
0 865.3 /
hp
t
0.7(0.4 + 1.2 )β f
β s
= 0.7 × (0.4 + 1.2 ) × 0.993 ×1570
2
= 1091.3kN / m2 > τ
满足要求。
max
= 865.3kN / m2
②抗剪承载力验算:
V = 5206 = 714.2kN
s 2.7 × 2.7
受剪切承载力截面高度影响系数 βhs :
1 1
βhs
= (800 ) 4 = (800 ) 4 = 0.974
h0 890
0.7β hs ft bwh0 = 0.7 × 0.974 ×1570 ×1× 0.89 = 952.7kN > Vs = 714.2kN
满足要求。
2、 边柱:取柱轴力最大处,即 10 轴/F 轴 由地下室 PKPM 竖向导荷,知:
Fl = 2964 + 146 × 2 + 75 + 158 × 2 + 137 + 98 = 3882kN :
①抗冲切承载力验算:
由上述计算知道
um = 4180mm ; c1 = 1245mm ; c2 = 1690mm ; cAB = 874.2mm
s
I = 7797.3 ×108 mm4
考虑作用在冲切临界截面重心上的不平衡弯矩较小,本计算予以忽略。即: M unb = 0
因底板外挑1.2m ,故距柱边 h0 处冲切临界截面的周长
2
um = 2c1 + 2c2 = 2 ×1245 + 2 ×1690 = 5870mm h
距柱边 0 处冲切临界截面的最大剪应力τ :
2
τ = Fl
+ α s M unbcAB =
3882
max
+ =
kN m2
max
um h0 I s
5.87 × 0.89
0 743.1 /
hp
t
0.7(0.4 + 1.2 )β f
β s
= 0.7 × (0.4 + 1.2 ) × 0.993 ×1570
2
= 1091.3kN / m2 > τ
满足要求。
max
= 743.1kN / m2
②抗剪承载力验算:
V = 3882 = 532.5kN
s 2.7 × 2.7
受剪切承载力截面高度影响系数 βhs :
1 1
βhs
= (800 ) 4 = (800 ) 4 = 0.974
h0 890
0.7β hs ft bwh0 = 0.7 × 0.974 ×1570 ×1× 0.89 = 952.7kN > Vs = 532.5kN
满足要求。
3、 角柱:取柱轴力最大处,即 1 轴/J 轴: 由地下室 PKPM 竖向导荷,知:
Fl = 2947 + 146 + 137 + 116 + 79 + 167 + 86 + 77 + 25 + 80 = 3860kN
①抗冲切承载力验算: 由上述计算知道
um = 2490mm ; c1 = 1245mm ; c2 = 1245mm ; cAB = 830.0mm
s
I = 4548.1×108 mm4
考虑作用在冲切临界截面重心上的不平衡弯矩较小,本计算予以忽略。即: M unb = 0
因底板外挑1.2m ,故距柱边 h0 处冲切临界截面的周长
2
um = 2c1 + 2c2 = 2 ×1245 + 2 ×1245 = 4980mm h
距柱边 0 处冲切临界截面的最大剪应力τ :
2
τ = Fl
+ α s M unbcAB =
3860
max
+ =
kN m2
max
um h0 I s
4.98 × 0.89
0 870.9 /
hp
t
0.7(0.4 + 1.2 )β f
β s
= 0.7 × (0.4 + 1.2 ) × 0.993 ×1570
2
= 1091.3kN / m2 > τ
满足要求。
max
= 870.9kN / m2
②抗剪承载力验算:
V = 3860 = 529.5kN
s 2.7 × 2.7
受剪切承载力截面高度影响系数 βhs :
1 1
βhs
= (800 ) 4 = (800 ) 4 = 0.974
h0 890
0.7β hs ft bwh0 = 0.7 × 0.974 ×1570 ×1× 0.89 = 952.7kN > Vs = 529.5kN
满足要求。
⑶筏板承载力计算: 计算模型为倒无梁楼盖,无帽顶板柱帽,采用等代框架法计算。 等代框架法是把整个结构分别沿纵、横柱列划分为具有“等代框架柱”和“等代框
架梁”的纵向等代框架和横向等代框架。
①X 方向 A、等代框架构件尺寸确定: 等代梁:(取 E 轴计算)
12000 + 84000
取梁截面宽度取板跨中心线间距 = 10200mm
2
梁截面高度取板厚 950mm;
本结构采用无帽顶板柱帽。 梁跨度取8400mm ; 梁截面惯性矩为:
Ib =
1 ×10.2 × 0.953 = 0.729m4
12
等代柱:
柱截面尺寸800mm × 800mm 柱高: 5175mm 柱截面惯性矩:
Ib =
1 × 0.8 × 0.83 = 0.0341m4
12
B、内力计算
梁上均布荷载 q = 61.6 ×10.2 = 628.32kN / m
其中 61.6 为地基净反力。 取 q = 630kN / m
计算简图如下:
分层法和弯矩分配法计算如下: 利用对称性取半跨,柱弯矩传递系数取 0.5,计算简图如下:
计算各杆转动刚度及分配系数:
iAG
= E × 0.0341 = 0.00659E
5.175
iAB
= E × 0.729 = 0.08679E
8.4
令 iAG = i
则 iAB = 13.2i
各杆转动刚度:
S AG = 4i
S AB = 4 ×13.2i = 52.8i
SEF = 13.2i
各杆分配系数:
uAG
= S AG
∑ S
A
= 4i
56.8i
= 0.070
uAB
= S AG
∑ S
A
= 52.8i = 0.930
56.8i
uBH
u
= SBH
∑ S
B
= SCK
= 4i
109.6i
= 4i
= 0.036
= 0.036
uBA
u
= uBC
= u
= SBA
∑ S
A
= SCB
= 52.8i
109.6i
= 52.8i
= 0.482
= 0.482
CK ∑ S
C
109.6i
CB CD
∑ S 109.6i
C
uDM
= SDM
∑ S
D
= 4i
109.6i
= 0.036
uDC
= uDE
= SDE
∑ S
D
= 52.8i
109.6i
= 0.482
uEN
= SEN
∑ S
E
= 4i
70.0i
= 0.057
uED
= SED
∑ S
E
= 52.8i = 0.754
70.0i
uEF
= SEF
∑ S
E
= 13.2i = 0.189
70.0i
计算各杆件由荷载所产生的固端弯矩:
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
AB 12
M =
F 1 ql 2 =
BA 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
BC 12
M =
F 1 ql 2 =
CB 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
CD 12
M =
F 1 ql 2 =
DC 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
DE 12 12
M =
F 1 ql 2 =
ED 12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1 × 630.0 × 8.42 = −14817.6kN ·m
EF 3 3
M F = − 1 ql 2 = − 1 × 630.0 × 8.42 = −7408.8kN ·m
FE 6 6
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弯矩分配法计算过程见下图:
弯矩图如下:
筑龙网
则弯矩最大值为:
M EF = 12485.3kN ·m ; 由下表:
等代框架法板带分配弯矩系数
截面
柱上板带
跨中板带
内跨
支座负弯矩
0.75
0.25
跨中正弯矩
0.55
0.45
边跨
第一内支座负弯矩
跨中正弯矩 边跨支座负弯矩
0.75
0.55
0.9
0.25
0.45
0.10
得:
内跨柱上板带分配弯矩: M = 0.75 ×12485.3 = 9364.0kN ·m 内跨跨中板带分配弯矩: M = 0.55 ×12485.3 = 6866.9kN ·m C、配筋计算:
取弯矩最大处进行计算。即取 M = 9364.0kN ·m
1
混凝土强度等级为 C 40 , fc
= 19.1N / mm2 ; α
= 1.0 ;受力钢筋均采用 HRB400
b
级,fy=360 N / mm2 ; ξ
相对受压区高度:
= 0.523 ; ρ
min
= 0.2% ;
x = h0 (1 −
2
1 − 2M )
α1 fcbh0
= 890 × (1 −
1 − 2 × 9364000000 )
1.0 ×19.1×10200 × 8902
= 55.8mm < xb = ξb h0 = 0.523 × 890 = 465.5mm
则
As =
α1 fcbx f y
= 1.0 × 19.1×10200 × 55.8
360
= 30197.1mm2
每米跨度配筋面积为: As1
= 30197.1 ×1000 = 2960.5mm2
10200
2
As min = 0.2% ×1000 × 950 = 1900mm
实际配筋:HRB400 级钢,直径 25,间距 130mm, 满足要求。
②Y 方向
A、等代框架构件尺寸确定: 等代梁:(取 5 轴计算)
梁截面宽度取板跨中心线间距8400mm ; 梁截面高度取板厚 950mm;
本结构采用无帽顶板柱帽。
梁跨度取分别为 7800mm,8400mm,12000mm。 梁截面惯性矩为:
s
A = 3776mm2
Ib =
1 × 8.4 × 0.953 = 0.600m4
12
等代柱:
柱截面尺寸800mm × 800mm 柱高: 5175mm 柱截面惯性矩:
Ib =
1 × 0.8 × 0.83 = 0.0341m4
12
B、内力计算
梁上均布荷载 q = 61.6 ×10.2 = 628.32kN / m
计算简图如下:
分层法和弯矩分配法计算如下:
截取 12 米跨度中点左半跨进行计算,柱弯矩传递系数取 0.5,计算简图如下:
计算各杆转动刚度及分配系数:
iBH
= E × 0.0341 = 0.00659E
5.175
iAB
= E × 0.60 = 0.10000E
6.0
iBC
= iCD
= iDE
= iEF
= E × 0.60 = 0.07143E
8.4
iFG
= E × 0.60 = 0.13043E
4.6
令 iBH = i
则 iAB = 15.2i
iBC = iCD = iDE = iEF = 10.8i iFG = 19.8i
各杆转动刚度:
S AB = 15.2i = 15.2i
SBC = SCD = SDE = SEF = 4 ×10.8i = 43.2i
SFG = 4 ×19.8i = 79.2i
SBH = 4 × i = 4i
各杆分配系数:
uBH
= SBH
∑ S
B
= 4i
62.4i
= 0.064
uBA
= SBA
∑ S
B
= 15.2i = 0.244
62.4i
uBC
= SBC
∑ S
B
= 43.2i = 0.692
62.4i
uCB
= uCD
= SCB
∑ S
C
= 43.2i = 0.478
90.4i
uCK
= SCK
∑ S
C
= 4i
90.4i
= 0.044
uDC
= uDE
= SDC
∑ S
D
= 43.2i = 0.478
90.4i
uDM
= SDM
∑ S
D
= 4i
90.4i
= 0.044
uED
= uEF
= SED
∑ S
E
= 43.2i = 0.478
90.4i
uEN
= SEN
∑ S
E
= 4i
90.4i
= 0.044
uFE
= SFE
∑ S
F
= 43.2i
126.4i
= 0.342
uFG
= SFG
∑ S
F
= 79.2i
126.4i
= 0.627
uFP
= SFP
∑ S
F
= 4i
126.4i
= 0.031
uGF
= SGF
∑ S
G
= 79.2i = 0.952
83.2i
uGQ
= SGQ
∑ S
G
= 4i
83.2i
= 0.048
计算各杆件由荷载所产生的固端弯矩:
M F = − 1 ql 2 = − 1 × 630.0 × 6.02 = −3780.0kN ·m
AB 6 6
M F = − 1 ql 2 = 1 × 630.0 × 6.02 = 7560.0kN ·m
BA 3 3
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
BC 12
M =
F 1 ql 2 =
CB 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
CD 12
M =
F 1 ql 2 =
DC 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
DE 12
M =
F 1 ql 2 =
ED 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 8.42 = −3704.4kN ·m
EF 12
M =
F 1 ql 2 =
FE 12
12
1 × 630.0 × 8.42 = 3704.4kN ·m
12
M F = − 1 ql 2 = − 1
× 630.0 × 4.62 = −1110.9kN ·m
FG 12
M =
F 1 ql 2 =
GF 12
12
1 × 630.0 × 4.62 = 1110.9kN ·m
12
弯矩分配法计算过程见下图:
弯矩图如下:
则弯矩最大值为:
M BA = 6528.7kN ·m ; 由下表:
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等代框架法板带分配弯矩系数
截面
柱上板带
跨中板带
内跨
支座负弯矩
跨中正弯矩
0.75
0.55
0.25
0.45
边跨
第一内支座负弯矩
跨中正弯矩 边跨支座负弯矩
0.75
0.55
0.9
0.25
0.45
0.10
得:
1
柱上板带分配弯矩: M = 0.75 × 6528.7 = 4896.5kN ·m 跨中板带分配弯矩: M = 0.55 × 6528.7 = 3590.8kN ·m C、配筋计算:
混凝土强度等级为 C 40 , fc
= 19.1N / mm2 ; α
= 1.0 ;受力钢筋均采用 HRB400
b
级,fy=360 N / mm2 ; ξ
相对受压区高度:
= 0.523 ; ρ
min
= 0.2% ;
x = h0 (1 −
1 − 2M )
2
α1 fcbh0
= 890 × (1 −
1 − 2 × 4896500000 )
1.0 ×19.1× 8400 × 8902
= 35.0mm < xb = ξb h0 = 0.523 × 890 = 465.5mm
则
As =
α1 fcbx f y
= 1.0 × 19.1× 8400 × 35
360
= 15598mm2
每米跨度配筋面积为: As1
= 15598 ×1000 = 1856.9mm2
8400
2
s
As min = 0.2% ×1000 × 950 = 1900mm
实际配筋:HRB400 级钢,直径 25,间距 130mm, 满足要求。
A = 3776mm2
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