第6章 竖向荷载作用下内力计算
§6.1 框架结构的荷载计算
§6.1.1.板传荷载计算
计算单元见下图所示:
因为楼板为整体现浇,本板选用双向板,可沿四角点沿45°线
将区格分为小块,每个板上的荷载传给与之相邻的梁,板传至梁上的三角形或梯形荷载可等效为均布荷载。
图6-1 框架结构计算单元
标准
实用文案
图6-2 框架结构计算单元等效荷载
一.B~C, (D~E)轴间框架梁: 屋面板传荷载:
恒载:6.09KN/m21.5m[1-2(1.5/6)2(1.5/6)2]2=17.128KN/m 活载:2.0KN/m21.5m[1-2(1.5/6)2(1.5/6)2]2=5.625KN/m 楼面板传荷载:
恒载:3.83KN/m21.5m[1-2(1.5/6)2(1.5/6)2]2=10.772KN/m 活载:2.0KN/m21.5m[1-2(1.5/6)2(1.5/6)2]2=5.625KN/m 梁自重:3.95KN/m
B~C, (D~E)轴间框架梁均布荷载为: 屋 面 梁:恒载=梁自重+板传荷载
=17.128 KN/m+3.95 KN/m=21.103 KN/m
活载=板传荷载=5.625 KN/m 楼面板传荷载:恒载=梁自重+板传荷载
=3.95 KN/m+10.772 KN/m=14.747 KN/m
活载=板传荷载=5.625 KN/m 二. C~D轴间框架梁: 屋面板传荷载:
恒载:6.09KN/m21.2m5/82=9.135KN/m 活载:2.0KN/m21.5m5/82=3KN/m 楼面板传荷载:
标准
实用文案
恒载:3.83KN/m21.25/82=5.745KN/m 活载:2.0KN/m21.2m5/82=3.75KN/m 梁自重:3.95KN/m
C~D轴间框架梁均布荷载为:
屋 面 梁:恒载=梁自重+板传荷载
=2.349 KN/m+9.135 KN/m=11.484 KN/m
活载=板传荷载=3 KN/m 楼面板传荷载:恒载=梁自重+板传荷载
=2.349 KN/m+5.745KN/m=8.09KN/m
活载=板传荷载=3.75 KN/m 三.B轴柱纵向集中荷载计算: 顶层柱:
女儿墙自重:(做法:墙高900㎜,100㎜的混凝土压顶)
0.24m0.9m18kn/m325KN/m30.1m0.24m
1.2m20.24m0.5m5.806KN/m
顶层柱恒载=女儿墙+梁自重+板传荷载
=
5.806KN/m63.975KN/m(6m0.6m)121.5/621.5/626/426.09KN/m1.5m5/832123.247KN 顶层柱活载=板传荷载
22=2.0KN/m1.5m121.5/61.5/66/42
2.0KN/m1.5m5/83219.688KN
标准层柱恒载=墙自重+梁自重+板荷载=
7.794KN/m(60.6)3.975KN/m(60.6)3.83KN/m1.5m5/832 (2.332311.52)61/422.3325KN/m61/42
223.83m1.5m121.5/61.5/66/42124.172KN
标准层柱活载=板传荷载
标准
实用文案
22=2.0m1.5m121.5/61.5/632.0m1.5m5/83219.688KN
基础顶面荷载=底层外纵墙自重+基础自重
=9.738KN/m(6m0.6m)2.5KN/m(6m0.6m)16.085KN 四.C柱纵向集中力计算: 顶
层
柱
荷
载
=
梁
自
重
+
板
传
梁
荷
载
=
3.975KN/m(90.9)m2.349KN/m(1.20.3)m6.09KN/m1.5m5/832
6.09KN/m1.2m5/81.22(2.3323KN/m11.52KN/m)6m1/42
154.318KN
顶层柱活载=板传荷载 =
222.0m1.5m121.5/61.5/63222.0m1.2m121.2/61.2/632.0m1.2m5/81.222.0m1.5m5/83239.272KN 标准柱恒载=墙+梁自重+板传荷载
=11.52KN/m(30.6)m15.12KN/m(30.6)m15.12KN/m(30.6)m
2.349KN/m(1.20.3)m3.975KN/m(60.6)m6.09KN/m1.5m5/8326.09KN/m6m1/21/22.67KN/m2.4/2m63.83KN/m23m6m200.173KN标准层活载=板传荷载
=2.0KN/m23m6m2.5KN/m21.2m6m54KN 基础顶面恒载=底层外纵墙自重+基础自重
9.738KN/m(6m0.6m)2.5KN/m(6m0.6m)66.085KN
(3).框架柱自重:
柱自重: 底层:1.2×0.6m×0.6m×25KN/m3×4.55m=49.14KN 其余柱:1.2×0.6m×0.6m×25KN/m3×3.6m=38.88KN
§6.2恒荷载作用下框架的内力
§6.2.1.恒荷载作用下框架的弯矩计算
标准
实用文案
一.恒荷载作用下框架可按下面公式求得:
Mab1/12ql2 (61) Mba1/12ql2 (62)
故:MB7C71/1221.036263.09KN.m
MC7B763.09KN.m
MC7D71/1211.484625.512KN.m
MC7D75.512KN.m
MB6C61/1214.7476244.241KN.m
MC6B644.241KN.m
MC6D61/128.09623.883KN.m
MD6C63.883KN.m
恒荷载作用下框架的受荷简图如图6-3所示:
标准
实用文案
图6-3竖向受荷总图:
注:1.图中各值的单位为KN
2.图中数值均为标准值 3.图中括号数值为活荷载
图6-4:恒载作用下的受荷简图
(2).根据梁,柱相对线刚度,算出各节点的弯矩分配系数ij:
iji/(icib) (63)
分配系数如图6-5 , 图6-6所示:
图6-5 B柱弯矩各层分配系数简图
B柱:
底层:i下柱=0.801/(0.8010.6091.0)0.332
i上柱=1.0/(0.8010.6091.0)0.415
i左梁=0.609/(0.8010.6091.0)0.253
标准层:i上柱=1.0/(0.6091.01.0)0.383
i下柱=1.0/(0.6091.01.0)0.383
i左梁=0.609/(0.6091.01.0)0.234 顶层: i下柱=1.0/(0.6091.0)0.622
i左梁=0.609/(0.6091.0)0.622
标准
实用文案
图6-6 C柱弯矩各层分配系数简图
C柱: i右梁=0.609/(0.6091.00.2110.801)0.232
i上柱=1.0/(0.6091.00.2110.801)0.382i下柱=0.801/(0.6091.00.2110.801)0.306
i左梁=0.211/(0.6091.00.2110.801)0.081
标准层:i下柱=1.0/(0.6091.00.2110.801)0.355
i上柱=1.0/(0.6091.00.2110.801)0.355
i右梁=0.609/(0.6091.00.2110.801)0.216 i左梁=0.211/(0.6091.00.2110.801)0.074
顶层: i下柱=1.0/(0.6091.00.211)0.549
i左梁=0.211/(0.6091.00.211)0.116 i右梁=0.609/(0.6091.00.211)0.335
三.恒荷载作用下的弯矩剪力计算,根据简图(6-4)
2梁:MA0 MAMB1/2qlQB.l0
QBMAMB/l1/2ql
MB0 MAMB1/2ql2QA.l0
QAMAMB/l1/2ql (6-4) 柱:MC0 MCMDQD.h0
QD(MCMD)/h
MD0 MCMDQC.h0
QC(MCMD)/h (6-5)
四.恒荷载作用下的边跨框架的轴力计算,包括连梁传来的荷载及柱自重.
标准
实用文案
N7123.24721.1036/2186.556KNN6N7124.17214.7476/238.88393.849KN N5N6124.17214.7476/238.88601.142KN N4N5124.17214.7476/238.88808.435KN N3N4124.17214.7476/238.881015.728KN N2N3124.17214.7476/238.881223.021KN N1N2124.17214.7476/238.881382.487KN
恒荷载作用下的中跨框架的轴力计算:
N7154.31811.4842.4/2168.099KNN6N7200.1738.092.4/238.88416.88KN N5N6200.1738.092.4/238.88665.621KN N4N5200.1738.092.4/238.88808.435KN N3N4200.1738.092.4/238.881015.728KN N2N3200.1738.092.4/238.881223.021KN N1N2200.1738.092.4/238.881382.487KN
图6-5 恒荷载作用下的计算简图
五.弯矩分配及传递
弯矩二次分配法比分层法作了更进一步的简化。在分层法中,用弯矩分配法计算分层单元的杆端弯矩时,任一节点的不平衡弯矩都将影响到节点所在单元中的所有杆件。而弯矩二次分配法假定任一节点的不平衡弯矩只影响至与该节点相交的各杆件的远端。因此可将弯矩分配法的循环次数简化到一次分配、一次传递、再一次分配。
标准
实用文案
所以本框架设计采用弯矩分配法计算框架内力,传递系数为1/2。各节点分配两次即可。
如表6-1所示:
表6-1 恒载作用下的框架弯矩内力二次分配表
标准
实用文案
上柱下柱左梁右梁上柱下柱左梁右梁下柱上柱左梁右梁下柱上柱
标准
实用文案
48.4448.4444.2353.029.79-1.5243.7943.7944.2237.2253.0244.2348.4448.4443.2916.3227.4744.2237.2243.7916.3227.474.1662.570.6662.5715.7115.7142.3542.3541.1820.5920.5924.6041.1824.6020.5920.594.818.781.0218.7818.7818.7842.3542.3541.7820.5920.5924.6041.7824.6020.5920.594.818.781.0218.7818.7818.7842.3542.3541.7820.5920.5924.6041.7824.6020.5920.594.818.781.0218.7818.7818.7842.3542.3541.7821.0320.3224.6041.7824.6020.3221.034.818.591.3218.5919.1319.1340.540.538.6913.4325.2626.7738.6926.7725.2613.434.522.561.3222.5612.3312.336.726.166.166.72
图6-5 恒荷载作用下的弯矩图 单位(KN.m)
标准
实用文案
六. 恒载作用下的的框架弯矩图
对于无荷载直接作用的杆件(如柱),将其柱端的弯矩连以直线,即为该杆件的弯矩图;对于有荷载作用的杆件(如梁),则以杆端弯矩的连线为基线。叠加相应简支梁的弯矩图,即为该杆件的弯矩图。
弯矩图如上图6-5所示 1.则梁跨中弯矩为:
F2211MB7C7中821.103KN/m6m2(48.22KN.m53.02KN.m)44.23KN.m
F2211MC7D7中811.484KN/m6m2(9.79KN.m9.79KN.m)1.52KN.m
F114.747KN/m62m21(43.29KN.m44.22KN.m)37.22KN.m MB6C6中82F111.484KN/m62m21(4.16KN.m4.16KN.m)1.66KN.m MC6D6中82F121.103KN/m62m21(41.18KN.m42.35KN.m)24.6KN.m MB5C5中82F2211MC5D5中811.484KN/m6m2(4.8KN.m4.8KN.m)1.02KN.m
FFFF MB5C5中MB4C4中MB3C3中MB2C2中24.6KN/mFFF MCMM5D5中C4D4中C3D3中1.02KN/mF2211MC2D2中811.484KN/m6m2(4.5KN.m4.5KN.m)1.32KN.m
F2211MB1C1中821.103KN/m6m2(38.69KN.m40.5KN.m)226.77KN.m
F2211MC1D1中811.484KN/m6m2(4.5KN.m4.5KN.m)1.32KN.m
七.恒载作用下剪力计算 1.梁端剪力:
QA7(MAMB)/L1/2ql(48.4453.02)/61/221.03662.327KN QB7(MAMB)/L1/2ql(48.4453.02)/61/221.03662.853KN
`QA7(MAMB)/L1/2ql13.781KN
标准
实用文案
`QB7(MAMB)/L1/2ql13.781KN
QB6(MAMB)/L1/2ql(43.7953.02)/61/221.03644.169KN QB6(MAMB)/L1/2ql(48.4453.02)/61/221.03644.313KN
`QA6(MAMB)/L1/2ql9.708KN `QB6(MAMB)/L1/2ql9.708KN
QB5(MAMB)/L1/2ql(41.1842.35)/61/221.03644.046KN QB5(MAMB)/L1/2ql(41.1842.35)/61/221.03644.436KN
`QA5(MAMB)/L1/2ql9.708KN `QB5(MAMB)/L1/2ql9.708KN
QB4(MAMB)/L1/2ql(41.1842.35)/61/221.03644.046KN QB4(MAMB)/L1/2ql(41.1842.35)/61/221.03644.436KN`QA4(MAMB)/L1/2ql9.708KN `QB4(MAMB)/L1/2ql9.708KN
QB3(MAMB)/L1/2ql(41.3542.47)/61/221.03644.054KN QB3(MAMB)/L1/2ql(41.3542.47)/61/221.03644.428KN
`QA3(MAMB)/L1/2ql9.708KN `QB3(MAMB)/L1/2ql9.708KN
QB2(MAMB)/L1/2ql(38.6940.496)/61/221.03643.94KN QB2(MAMB)/L1/2ql(38.6940.496)/61/221.03644.542KN` QA2(MAMB)/L1/2ql9.708KN
`QB2(MAMB)/L1/2ql9.708KN
2.柱端剪力:
Q7(48.44427.47)/3.621.09KN
`Q7(43.2924.35)/3.618.79KN
Q6(16.3220.59)/3.610.25KN
`Q6(15.7118.78)/3.69.58KN
Q5Q4(20.5920.59)/3.611.44KN``Q5Q4(18.7818.78)/3.610.43KN
Q3(20.5920.32)/3.611.36KN
`Q3(12.3296.16)/3.610.38KN
Q2(21.0325.26)/3.612.86KN
标准
实用文案
`Q2(19.1322.563)/3.611.58KN
Q1(13.436.72)/4.554.43KN Q1`(12.3296.16)/4.554.06KN
图6-6 恒载作用下的剪力图
注:
由于该框架结构左右对称,所以竖向荷载作用下框架剪力图反对称。
标准
实用文案
§6.3活荷载作用下框架的内力
§6.3.1活载作用下的框架内力
同恒载作用下用弯矩分配法计算框架内力,折减系数为1/2,各节点分配两次即可。
活荷载作用下框架内力如表6-2所示:
§6.3.2.活荷载作用下框架的内力计算 一.梁端的固端弯矩可按下面的方法求得;
Mab1/12ql2 M2ba1/12ql 故:Mab1/125.6256616.875
Mba1/125.6256616.875
MCD1/1232.42.41.44 MDC1/1232.42.41.44
M`CD1/123.752.42.41.8 M`Dc1/123.752.42.41.8
标准
(66) (67)
实用文案
图6-7 恒载作用下的轴力图(单位KN)代表压力,BC轴与DE轴对称。
标准
实用文案
13.32813.32811.1415.02515.02511.1413.32813.3280.51.6610.9443.7916.54416.54416.1547.089.098.9616.1548.969.097.082.0380.398.018.016.456.4516.20416.20415.6847.857.859.3715.6849.3770.007.857.850.9381.7626.476.476.476.4716.20416.2040.9381.7626.476.476.476.4716.2040.9381.76213.146.476.476.476.4716.24416.2442.1380.566.476.476.476.4715.9315.933.550.858.078.074.244.2416.20415.6847.857.859.3715.6849.377.857.8515.6847.857.859.379.3715.6847.857.8515.6847.7358.0059.3215.6849.328.0057.73514.739.6155.119.3214.739.325.119.6152.5522.122.122.552
图6-8活荷载作用下的弯矩图
标准
实用文案
表6-2 活荷载作用下的弯矩内力二次分配表
上柱下柱左梁右梁上柱下柱左梁右梁下柱上柱左梁右梁下柱上柱二. 活载作用下的的框架弯矩图
对于无荷载直接作用的杆件(如柱),将其柱端的弯矩连以直线,即为该杆件的弯矩图;对于有荷载作用的杆件(如梁),则以杆端弯矩的连线为基线。叠加相应简支梁的弯矩图,即为该杆件的弯矩图。
弯矩图如上图6-5所示
标准
实用文案
1.则梁跨中弯矩为:
F2211MB7C7中85.625KN/m6m2(13.328KN.m15.025KN.m)11.14KN.m
F13KN/m62m21(0.5KN.m0.5KN.m)1.66KN.m MC7D7中82F15.625KN/m62m21(16.154KN.m16.544KN.m)8.96KN.m MB6C6中82F2211MC6D6中83KN/m6m2(2.308KN.m2.308KN.m)0.39KN.m
F2211MB5C5中85.625KN/m6m2(15.684KN.m16.204KN.m)9.37KN.m
F2211MC5D5中83.75KN/m6m2(0.938KN.m0.938KN.m)1.762KN.m
FFFF MB5C5中MB4C4中MB3C3中MB2C2中9.37KN/mFFF MC5D5中MC4D4中MC3D3中1.762KN/mF2211MC2D2中83.75KN/m6m2(2.138KN.m2.138KN.m)0.56KN.m
F2211MB1C1中85.625KN/m6m2(14.73KN.m14.73KN.m)9.32KN.m
F13.75KN/m62m21(3.55KN.m3.55KN.m)0.85KN.m MC1D1中82三.活荷载作用下的框架剪力计算
根据简图(6-4)和推导公式计算其活荷载作用下的剪力 如图(6-9)所示: 1.梁端剪力:
QA7(MAMB)/L1/2ql(13.32815.025)/61/25.625616.592KNQB7(MAMB)/L1/2ql(13.32815.025)/61/25.625617.158KN`QA7(MAMB)/L1/2ql1/232.43.6KN`QB7(MAMB)/L1/2ql1/232.43.6KN
QB6(MAMB)/L1/2ql(16.15416.544)/61/25.625616.81KN QB6(MAMB)/L1/2ql(16.15416.544)/61/25.625616.94KN标准
实用文案
`QA6(MAMB)/L1/2ql1/22.43.754.5KN`QB6(MAMB)/L1/2ql1/22.43.754.5KN
QB5(MAMB)/L1/2ql(15.68416.204)/61/25.625616.788KNQB5(MAMB)/L1/2ql(15.68416.204)/61/25.625616.96KN`QA5(MAMB)/L1/2ql1/23.752.44.5KN`QB5(MAMB)/L1/2ql1/23.752.44.5KN
QB4(MAMB)/L1/2ql(15.68416.204)/61/25.625616.788KNQB4(MAMB)/L1/2ql(15.68416.204)/61/25.625616.96KN`QA4(MAMB)/L1/2ql1/23.752.44.5KN`QB4(MAMB)/L1/2ql1/23.752.44.5KN
QB3(MAMB)/L1/2ql(15.68416.204)/61/25.625616.792KNQB3(MAMB)/L1/2ql(15.68416.204)/61/25.625616.958KN`QA3(MAMB)/L1/2ql1/23.752.44.5KN`QB3(MAMB)/L1/2ql1/23.752.44.5KN
QB2(MAMB)/L1/2ql(14.7315.93)/61/25.625616.675KN QB2(MAMB)/L1/2ql(14.7315.93)/61/25.625617.075KN
`QA2(MAMB)/L1/2ql1/23.752.44.5KN`QB2(MAMB)/L1/2ql1/23.752.44.5KN
2.柱端剪力:
Q7(13.3283.09)/3.66.223KN
`Q7(10.948.01)/3.65.26KN
Q6(7.087.85)/3.64.147KN
`Q6(6.456.47)/3.63.589KN
Q5Q4(7.857.85)/3.64.361KN
``Q5Q4(6.476.47)/3.63.594KN
Q3(7.858.005)/3.64.404KN
`Q3(6.476.96)/3.63.731KN
Q2(7.7355.11)/3.63.568KN
`Q2(7.18.07)/3.64.214KN
Q1(9.6152.552)/4.552.674KN Q1`(4.242.12)/4.551.398KN
标准
实用文案
活载作用下的剪力图详见图6-10 三. 活荷载作用下的内力计算
1.边跨框架的轴力计算,包括连梁传来的荷载及柱自重
N719.6885.6256/236.563KN N6N719.6885.6256/273.126KN N5N619.6885.6256/2109.689KN N4N519.6885.6256/2146.252KN N3N419.6885.6256/2146.252KN N2N319.6885.6256/2219.378KN N1N219.6885.6256/2255.941KN
2.活荷载作用下的中跨框架的轴力计算:
N739.27232.4/242.872KN N6N7543.752.4/238.88101.372KN N5N6543.752.4/238.88159.872KN N4N5543.752.4/238.88218.372KN N3N4543.752.4/238.88276.872KN N2N3543.752.4/238.88335.372KN N1N2543.752.4/238.88393.872KN
标准
实用文案
图6-9 活载作用的轴力图 单位KN,代表压力,BC轴与DE轴对称
标准
实用文案
图6-10 活载作用下的剪力图
注:由于框架结构左右对称,所以竖向荷载作用下框架剪力图反对称
标准
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