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1、8荷载效应效应组合本设计所应用到的用于承载力量极限状态下的内力组合公式如下：无地震时，由可变荷载效应掌握的组合：S=Yggk*qYqqk+WKySWK式中S一结构构件荷载效应组合的设计值，包括组合的弯矩、轴向力和剪力设计值；巾、地、vl永久荷载、楼面活荷载和风荷载的分项系数；附、ML楼面活荷载和风荷载的组合系数，当为第一可变荷载时取1。Sgk、SQk.SM一永久荷载、楼面荷载和风荷载效应标准值。无地震时，由永久荷载效应掌握的组合（依据建筑结构荷载法律规范GB5（XX）92001第条注3,水平风荷载不参与组合。但2006版法律规范中取消了此注，即水、m荷我参与组合，当风荷载效应不大时也可忽视之。
2、）：S=Sgk+WqYqSqk有地震时，即重力荷载与水平地震作用的组合：S=YgSge+7劭SEW式中S一结构构件荷载效应与地震作用效应组合的设计值；%、俎一重力荷载、水平地震作用的分项系数；SGE、SE7,一重力荷载代表值、水平地震作用标准值。用于正常使用极限状态下的内力组合（标准组合）公式如下：S=SGK+WQSQK+SVVK8.1 掌握截面及最不利内力类型8.1.1 构件的掌握截面框架梁的掌握截面是支座截面和跨T截面。在支座截面处，一般产生最型弯矩JMmaJ和最大剪力（VmaX）（水平荷载作用下还有正弯矩产生，故也要留意组合可能消失的正弯矩）；跨间截面则是最大正弯矩（+MUUJ作用处（也
3、要留意组合可能消失的负弯矩）O因此，IE架梁的最不利内力用梁端截面：+Mma.-fma.gw梁跨间截面：+Mmax由于内力分析的结果是轴线位置处的内力，而梁支座截面的最不利位置应是柱边缘处，因此，在求该处的最不利内力时，应依据梁轴线处的弯矩和剪力计算出柱边缘处梁截面的弯矩和剪力，即：M=M-Vb2V,=V-qb2式中一柱边缘处梁截面的弯矩标准值；V一柱边缘处梁截面的剪力标准值；梁柱中线交点处的弯矩标准值；V与M相应的梁柱中线交点处的剪力标准值；b一柱截面高度；夕一梁单位长度的均布荷载标准值。依据框架结构的合理破坏形式，在梁端消失塑性钱是允许的;为了便于浇捣退凝土,也往往盼里F点处梁的钢筋放得少
4、此。因此，在进行框架结构设计时，一般均对换算到柱边缘处梁截面的弯矩进行调幅，即人为地削减梁端负弯矩，减小节点四周梁顶面的配筋量。设某框架梁AB在竖向荷载作用下，梁端最大负弯矩分别为知.。、Mli0t梁跨中最大正弯矩为Me，则调幅后梁端弯矩可取：MA=BMM)MB=PMBo式中，夕为弯矩调幅系数。对于现浇框架，可取夕=0.80.9。梁端弯矩调幅后，在相应荷载作用下的跨中弯矩必进增加，!防支座消失塑性较后，导致跨中截面承载力不足。fi常跨中弯矩乘以1.1L2的调整系斜。这时应核对静力平衡条件，即调幅后梁端弯矩M八、的平均值与跨中最大正弯矩Me之和应大于按简支梁计算的跨中弯矩值(或1.05Mo)om
5、+mh1 2glMo必需指出，有关法律规范规定，弯矩调幅只对竖向荷载作用下的内力进行,而水平荷载作用下产生的弯矩不参与调幅，因此，,矩调幅应在内力组合之前进行J同时规定，梁截面设计时所采纳的跨中正弯矩不应小于按简支梁计算的跨中弯矩之半,即Me20剪力不用进行调幅，内力组合时直接用来进行内力组合。1.1. 2框架梁的掌握截面内力换算及竖向荷载作用下的梁弯矩塑性调幅(1)竖向荷载作用下框架梁的掌握截面内力换算及弯矩调幅。计算过程见下表。表8.1计算竖向荷载各支座边缘截面的弯矩标准值及调幅后弯矩层数内力性质IMIkNmIVIZkNkNmb/mMkNmVlikNMkNm7左竖向恒载201.441822
6、6.770.55-151.39174.64-121.11右201.9918226.770.55-151.94-174.64-121.556左266.5201.524.50.55-211.09194.76-168.87右278.76211.1724.50.55-220.69-204.43-176.555左222.43176.8526.280.55-173.80169.62-139.04右212.33161.0726.280.55-168.04-153.84-134.434左215.97176.8526.280.55-167.34169.62-133.87右206.4161.0726.280.55
7、-162.11-153.84-129.683左167.19129.5118.90.55-131.57124.31-105.26行166.06126.5618.90.55-131.26-121.36-105.002左226.88179.8926.280.65-168.42171.35-134.73行236.27177.4926.280.65-178.59-168.95-142.871左299.28188.826.280.65-237.92180.26-190.34(1190.02149.1226.280.65-141.56-140.58-113.24悬臂278.75107.9816.190.65
8、-243.66-102.72-194.937左竖向活载20.8614.762.110.55-16.8014.18-13.44右20.914.762.110.55-16.84-14.18-13.476左75.7161.398.460.55-58.8359.06-47.06右77.6762.548.460.55-60.47-60.21-48.385左76.4660.448.460.55-59.8458.11-47.87右76.5259.238.460.55-60.23-56.90-48.194左76.3560.448.460.55-59.7358.11-47.78右76.3359.238.460.
9、55-60.04-56.90-48.033左75.160.448.460.55-58.4858.11-46.78右75.2159.238.460.55-58.92-56.90-47.142左78.1560.58.460.65-58.4957.75-46.79右82.6661.38.460.65-62.74-58.55-50.191左84.1361.258.460.65-64.2258.50-51.38右77.558.428.460.65-58.51-55.67-46.81悬臂18.897.731.090.65-16.38-7.38-13.102)水平荷载作用下框架梁的掌握截面内力换算。计算过程
10、见下表。表8.2计算水平荷载各支座边缘截面的寿矩标准值层数内力性质IMlZkNmIVIZkNg/kN/mb/mMkNmVakN7风荷载11.922.8700.5511.132.87626.716.4400.5524.946.44545.7711.0300.5542.7411.03462.214.9900.5558.0814.99374.0817.8500.5569.1717.85293.0622.4200.6585.7722.421120.2528.9800.65110.8328.987地震作用50.4412.1500.5547.1012.15695.432300.5589.11235140.
11、3933.8300.55131.0933.834169.5140.8500.55158.2840.853182.6444.0100.55170.5444.012208.9850.3600.65192.6150.361242.6858.4800.65223.6758.488.2框架梁的荷载效应组合8.2.1框架梁端无地震作用时的荷载效应基本组合（见表8.3）8.2.2框架梁端有地震作用时的荷载效应基本组合（见表8.4）表8.3用于承载力计算的框架梁无地震时的基本组合层恒载活载左风右风无地震时由活载掌握由恒载掌握1.20+1.4(g)+0.6x1.41.2+1.4+0.6x1.41.2+1.4x0
12、.7班1.41.2(D+1.40.7+1.4L35+O.71.4(g)7左M-121.11-13.4411.13-11.13-154.80-173.50-142.92-174.09-176.67V174.6414.18-2.872.87227.01231.83219.45227.48249.66右M-121.55-13.47-11.1311.13-174.07-155.37-174.64-143.48-177.29V-174.64-14.18-2.872.87-231.83-227.01-227.48-219.45-249.666左M-168.87-47.0624.94-24.94-247.5
13、8-289.48-213.85-283.68-274.09V194.7659.06-6.446.44310.99321.81282.57300.61320.80右M-176.55-4838-24.9424.94-300.54-258.64-294.19-224.36-285.75V-204.43-60.21-6.446.44-335.02-324.20-313.34-295.31-334.995左M-139.04-47.8742.74-42.74-197.96-269.77-153.92-273.60-234.62V169.2658.11-11.0311.03275.20293.73244.6
14、2275.50285.45M-134.43-48.19-42.7442.74-264.68-192.88-268.38-148.71-228.71V-153.84-56.90-11.0311.03-273.53-255.00-255.81-224.93-263.454左M-133.87-47.7858.08-58.08-178.75-27632-126.16-288.78-227.55V169.6258.11-14.9914.99272.31297.49239.51281.48285.93右M-129.68-48.03-58.0858.08-271.65-174.07-284.00-121.3
15、7-222.14V-153.84-56.90-14.9914.99-276.86-251.68-26136-219.38-263.453左M-105.2646.7869.17-69.17-133.70-249.91-75.32-268.99-187.95V124.3158.11-17.8517.85215.53245.52181.13231.11224.77右M-105.00-47.14-69.1769.17-250.10-133.89-269.04-75.36-187.95V-121.36-56.90-17.8517.85-240.29-210.30-226.38-176.40-219.60
16、2左M-134.7346.7985.17-85.17-155.64-298.72-88.29-326.77-227.74V171.3557.75-22.4222.42267.64305.30230.83293.60287.92右M-142.87-50.19-85.1785.17-313.25-170.17-339.87-101.39-242.06V-168.95-58.55-22.4222.42-303.54-265.88-291.51-228.73-285.461左M-190.34-5138110.83-110.83-207.24-393.44-123.60-433.92-307.31V18
17、0.2658.50-28.9828.98273.87322.56233.07314.21300.68右M-113.24-46.81-110.83110.83-294.52-108.32-336.92-26.60-198.75V-140.58-55.67-28.9828.98-270.98-222.29-263.82-182.68-24434悬臂M-194.93-13.10-252.26-252.26-246.75-246.75-275.99V102.72-7.38112.93112.93116.03116.03138.67注：表中弯矩以下侧受拉为正，单位为kNm.表中V以绕梁端顺时针为正，单位
18、kN。表8.4用于承载力计算框架梁有地震时的基本组合表层恒载活载左震右震有地震时重力荷载与水平地震作用组合1.2(+0.5)+1.31.2(位5)+1.3SSXyRESSXyRE7左M-121.11-13.4447.10-47.10-84.10-63.08-206.56-154.92V174.6414.18-12.1512.15193.77225.36右M-121.55-13.47-47.1047.10-207.09-155.32-84.63-63.47V-174.64-14.18-12.1512.15-225.36-193.776左M-168.87-47.0689.11-89.11-115.
19、04-86.28-346.72-260.04V194.7659.06-23.0023.00239.25299.05右M-176.55-48.38-89.1189.11-356.73-267.55-125.05-93.78V-204.43-60.21-23.0023.00-31134-251.545左M-139.04-47.87131.09-131.09-25.15-18.86-365.99-274.49V169.2658.11-33.8333.83194.00281.96右M-134.43-48.19-131.09131.09-360.65-270.49-19.81-14.86V-153.84
20、-56.90-33.8333.83-262.73-174.774左M-133.87-47.78158.28-158.2816.4512.34-395.08-296.31V169.6258.11-40.8540.85185.31291.52右M-129.68-48.03-158.28158.28-390.20-292.6521.3316.00V-153.84-56.90-40.8540.85-271.85-165.643左M-105.26-46.78170.54-170.5467.3250.49-376.08-282.06V1243158.11-44.0144.01126.83241.25右M-
21、105.00-47.14-170.54170.54-375.99-281.9967.4250.56V-121.36-56.90-44.0144.01-236.99-122.562左M-134.73-46.79192.61-192.6160.6445.48-440.14-330.11V171.3557.75-50.3650.36174.80305.74右M-142.87-50.19-192.61192.61-451.95-338.9648.8436.63V-168.95-58.55-50.3650.36-303.34-172.401左M-190.34-51.38223.67-223.6731.5
22、423.65-550.01-412.51V180.2658.50-58.4858.48175.39327.44右M-113.24-46.81-223.67223.67-454.75-341.06126.8095.10V-140.58-55.67-58.4858.48-278.12-126.07悬臂M-194.93-13.10-24L78-181.33-241.78-181.33V102.72-7.38118.84118.84注：表中驾矩以下侧受拉为正，单位为kNm.表中V以绕梁端顺时针为正，单位kN。Vre为承载力抗震调整系数屋面的组合为1.2x+1.3x和1.2x+1.3x8. 2.3框架梁
23、各跨间最大正弯矩本设计各种组合状况下的跨间弯矩最大值不肯定在跨中截面，因此需要依据之前各种组g状况T的梁端弯矩和剪力及相应于该种组合的跨间荷载，找出跨间在不同组合状况下的剪力零点位置。然后对剪力零点位置列弯矩方程，求出不同组合状况下的跨间最大弯矩。以7层(屋面)框架梁为例，给出具体的计算过程：7层框架梁的跨间最大弯矩计算如下：(1)组合状况：1.2Sgk+14Sqk+0.6x1.4Sw也梁左端：V=227.01kNM=-154.80kNm梁右端:V=-231.83kNM=-174.07kN跨间荷载：梁左侧集中力F=1.270.961.4=93.48kN梁右侧集中力2=1.270.9+61.4=
24、93.48kN跨间均布荷载：1.226.77+2.Ilxl.4=35.08kN/m93.4893.48227.01231.83P47S-nn.-47s.(a)(b)图8.1(a)图为计算简图；(b)图是其剪力图(单位：kN)则跨间最大弯矩MIWd的位置：x=2.47546.71/35.08=2.475+1.332=3.806mMmaXl=227.013.08622=330.61kNm(2)组合状况：1.2Sgk+L4Sqk+0.6x1.4SwkgMmaxl=Mniaxl=330.61kN(3)组合状况1.2Sgk+0.7X1.4Sqk+1.4SWK左梁左端：V=219.45kNM=-142.9
25、2kNm梁右端：V=-227.48kNM=I74.64kN跨间荷载:梁左侧集中力F=L270.9+61.40.7=90.96kN梁右侧集中力72=1.270.9+61.40.7=90.96kN跨间均布荷载：q=,226.77+2.1Ix1.40.7=34.19kN/m90.9690.96219.45227.48I-475IPann-47s(a)(b)图8.2(a)图为计算简图；(b)图是其剪力图(单位：kN)则跨间最大弯矩MmaXI的位置：=2.47543.8734.19=2.475+1.283=3.758mMmaX3=219.45XX3.75822=323.65kNm(4)组合状况：1.2S
26、gk+14Sqk+06x1.4Swk右ma4=max3=323.65kNIYl(5)组合状况：1.35Sgk+07xL4Sqk梁左端：V=249.66kNM=-176.67kNm梁右端：V=-249.66kNM=-177.29kN跨间荷载：梁左侧集中力Fl=I.3570.9+61.4x0.7=101.60kN梁右侧集中力”2=1.3570.9+61.40.7=101.60kN跨间均布荷载：q=1.3526.77+2.11 1,40.7=38.21 kN/m249.66249.66P475图8.3计算简图其跨间最大正弯矩MmaX5在跨中。MmaX5=249.66X3.87522=361.65kN
27、m(6)组合状况：1.2(Sgk+OxSqk)+1.3Se啥梁左端：V=193.77kNM=-84.10kNm梁右端:V=-225.36kNM=-207.09kN跨间荷载：梁左侧集中力F=1.270.9=85.08kN梁右侧集中力72=1.270.9=85.08kN跨间均布荷载：q=285.0885.08193.7729.19(b)图8.4(a)图为计算简图；(b)图是其剪力图(单位：kN)则跨间最大弯矩Mnwd的位置：x=2.475+29.19/32.12=2.475+0.909=3.366mreMmax6=(193.77x3.36622)0.75=231.62kNm(7)组合状况：1.2(
28、Sgk+0xSqk)+L3Sek右YREMmax7%/REMmax6=231.62kN,因此，7层框架梁的跨间最大弯矩的掌握组合为1.35Sgk+07xL4Sqk,其跨间最大弯矩为MmaX=361.65kNm（留意：随着层数的降低，地震作用产生的正弯矩增大，跨间最大正弯矩位置可能向支座靠拢，很有可能是地震作用参与组合时产生的最大正弯矩大于非地震组合。）同理：其余各层的跨间最大弯矩经过计算和比较各种组合状况下的跨间最大弯矩。为节约篇幅，计算比较结果列于表8.5。8.2.4用于承载力计算时框架梁的最不利组合表8.5用于承载力计算的框架梁最不利组合表层Mmin及相应的VIVImax及相应的MMmaX
29、及相应的V组合项目值组合项目值组合项目值7左M1.35+0.7x1够-176.671.35+0.7x1.4-176.67V249.66249.66中M1.35+0.7xl.4361.65右M1.35+0.7x1.4-177.291.35+0.71.4(2)-177.29V-249.66-249.666左M1.2+1.4+0.6x1.4-289.4819+1阳+0.61.4-289.48V321.81321.81中M1.35+0.7x1.4349.66右M1.2+1.4+O.61.4(g)-300.541.2+1.4+0.6x1.4-300.54V-335.02-335.025左M1.2(D+0
30、.5)+1.3-274.491.2+1.4+0.6I.4-269.77V293.73中ML2+1.4(2)+0.61.4(g)292.50右M1.2(+0.5)+1.3-270.491.2+1.4(g)+0.6x1.4(-264.68V-273.534左M1.2(+0.5)+1.3-296.3119+1.晦+0.6x1.4-276.32V297.49中M1.2+1.4+0.6xl.4301.20右M1.2(D+0.5)+1.3-292.651.2+1.4+0.6x1.4-271.65V-276.663左M1.2(D+0.5)+1.3-282.06L2(D+1.4+0.6l.4-249.91V2
31、45.52中M1.2+1.4+0.6xl.4249.65右M1.2(+0.5)+1.3-281.9919+1够+0.61.4(3)-250.10V-240.292左M1.2(+0.5)+1.3-330.11+0.61.4(4)-298.72V305.30中M1.2+1.4+0.6x1.4306.17右M1.2+L4xO.7+1.4-339.871.2+1够+0.6l.4()-313.25V-291.51-303.541左M1.2+L4xO.7+1.4-433.921.2+1够+0.61.4(4)-393.44V314.21322.56中M1.2+1.4+0.6x1.4289.84右M1.2(+
32、0.5)+1.3-341.069+g+0.6X1.4(-294.52V-270.98悬臂M1.35+0.7x1.4-275.991.35+0.7x1.4-275.99V138.67138.67注：表中弯矩以下侧受拉为正，单位为可kNm.表中V以绕柱端顺时针为正，单位kN实际组合时，应考虑可能与最不利原则，在上述某一可能组合中，某些项不考虑。为了防止梁在弯曲屈服前先发生剪切破坏，截面设计时对于有地震组合的剪力设计值进行调整如下：式中：Hv剪力增大系数，对三级框架取1.1；In-梁的净跨。VGb梁在重力荷载作用下,按简支梁分析的梁端截面剪力设计值。M；,M；分别为梁的左、右端顺时针方向或反时针方向
33、截面组合的弯矩值。用公式=b(M+M()n+Vcb,计算出有地震组合的梁端剪力设计值并与无地震组合梁端剪力的最大值(见表8.5)作出比较，具体过程见下表8.6。表8.6梁剪力设计值计算表层Mbr(kNm)Mm(kNm)Ln(m)b(kN)Vb(kN)7左206.560.00?7.20209.57241.13右0.00?-207.097.20-209.57-241.216左346.720.007.20269.15322.12右0.00-356.737.20-281.44-335.945左365.990.007.20237.98293.90右0.00-360.657.20-218.75-273.8
34、54左395.0821.337.20238.41302.03右16.45-390.207.20-218.75-275.853左376.0867.427.20184.04251.80右-67.32-375.997.20-179.77-247.502左440.1448.487.00240.27317.05右-60.64-451.957.00-237.87-318.421左550.01126.807.00251.41357.77右-31.54-454.757.00-202.10-278.52注：计算梁左端剪力时使用右震的组合弯矩；反之，计算梁右端剪力用左震的组合弯矩。表8.7有地震组合梁端剪力设计值
35、与无地震组合梁端剪力设计值比较层截面iNmm2bmmhomm无地震作用组合有地震作用组合IVbIZkNr.TAMoZkNIVblZkNRE,-0.42t(kN7左1.43300635249.6658.97241.1390.55右1.43300635249.6658.97241.2190.616左1.43300635321.81131.12322.12159.39右1.43300635335.02144.33335.94171.135左1.43300635293.73103.04293.90135.40右1.43300635273.5382.84273.85118.364左1.433006352
36、97.49106.80302.03142.31右1.43300635276.4985.80275.85120.063左1.43300635245.5254.83251.8099.62右1.43300635240.2949.60247.5095.962左1.43300635305.3114.61317.05155.08右1.43300635303.54112.85318.42156.24I左1.43300635322.56131.87357.77189.69右1.43300635270.9880.29278.52122.33用于正常使用极限状态验算的框架梁基本组合（见表8.8）表8.8用于正常使用极限状态验算的框架梁基本组合表层恒载活载左风右风无地震时Mmin及相应的V+0.6论+0.6(4)+0.7+X).7组合项目值7左M-121.11-13.4411.13-11.13-127.87-141.23-119.39-141.65+0.7+-141.65V174.6414.18-2.872.87187.10190.54181.70187.44187.44右M-121.55-13.47-11.1311.13-141.70-12834-142.11-119.85+0.7+-142.11V-174.64-14.18-2.87
