竖向荷载作用下的内力计算.doc
.-竖向荷载作用下的内力计算4.1竖向荷载作用下荷载计算 由于二至六楼的楼面的完全采用一种做法,为了计算方便,我们只选取了二楼楼面进行计算,导荷方式如图所示:标准层屋面荷载计算(1)对2层楼板B1进行计算(7.8/4.2=1.86为双向板):传至纵向框架梁(KL 250500)D轴、梁(KL 250500)F轴上的荷载为三角形荷载。 恒载:3.99X4.2/2=8.379KN/m 活载:3.5X4.2/2=7.35KN/m若化为均布荷载: 恒载:8.379X5/8=5.24KN/m 活载:7.35X5/8=4.59KN/m传至框架梁(KL 250700)3轴上的荷载为梯形荷载。 恒载:3.99X4.2/2=8.379KN/m 活载:3.5X4.2/2=7.35KN/m 若化为均布荷载4.2/2x7.8=0.27恒载:(1-2X+)X8.379=7.33KN/m活载:(1-2X+)X4.2=3.671KN/m对2层楼板B2进行计算(4.2/3=1.4为双向板):传至纵向框架梁(KL 250400)3轴上的荷载为三角形荷载。 恒载:3.99X3/2=5.985KN/m 活载2.5X3/2=3.75KN/m 若化为均布荷载:恒载:5.985X5/8=3.741KN/m 活载:3.75X5/8=2.34KN/m传至框架梁(KL 250500)C轴、梁(KL 250500)D轴上的荷载为梯形荷载。 恒载:3.99X3/2=5.985KN/m 活载:2.5X3/2=3.75KN/m 若化为均布荷载3/2x4.2=0.357 恒载:(1-2X+)X5.985=4.74KN/m活载:(1-2X+)X3.75=2.97KN/m(2)梁(KL 250500)传给边柱(KZ-1)的集中荷载为:恒载梁自重 + 墙自重+ B1传荷载2(2.64+2.8)X(4.2+4.2)/2+5.24x4.2x2/2=44.86KN活载=B1传荷载24.59x4.2x2/2=19.28KN由于梁的形心与柱的形心不一致,因此梁传给柱的集中荷载可向柱形心简化为一个集中荷载与一个力矩恒荷载作用下(0.25-0.125)=44.86x0.125=5.61KN/m活荷载作用下(0.25-0.125)=19.28x0.125=2.41KN/m梁(KL 250500)传给中柱(KZ-1)的集中荷载为:恒载梁自重 + 墙自重 + B1传荷载2 + B2传荷载2(2.64+5.72)x(4.2x4.2)/2+5.24x4.2x2/2+4.732x4.2x2/2=77.03KN活载=B1传荷载2+ B2传荷载24.59x4.2x2/2+2.97x4.2x2/2=31.75KN由于梁的形心与柱的形心不一致,因此梁传给柱的集中荷载可向柱形心简化为一个集中荷载与一个力矩恒荷载作用下(0.25-0.125)=77.03x0.125=9.63KN.M活荷载作用下(0.25-0.125)=31.75x0.125=3.97KN.M屋面板传荷载:(1)对屋面板B1进行计算(7.8/4.2=1.86为双向板):传至纵向框架梁(KL 250500)D轴、梁(KL 250500)F轴上的荷载为三角形荷载。 恒载:5.12X4.2/2=10.75KN/m 活载:0.5X4.2/2=1.05KN/m若化为均布荷载: 恒载:10.75X5/8=6.72KN/m 活载:1.05X5/8=0.656KN/m传至框架梁(KL 250700)3轴上的荷载为梯形荷载。恒载:5.12X4.2/2=10.75KN/m 活载:0.5X4.2/2=1.05KN/m若化为均布荷载4.2/2X7.8=0.27 恒载:(1-2X+)X10.752=9.4KN/m 活载:(1-2X+)X1.05=0.92KN/m对屋面板B2进行计算(4.2/3=1.2为双向板):传至纵向框架梁(KL 250400)3轴上的荷载为三角形荷载。恒载:5.12X3/2=7.68KN/m 活载:0.5X3/2=0.75KN/m若化为均布荷载: 恒载:7.68X5/8=4.8KN/m 活载:0.75X5/8=0.469KN/m 传至框架梁(KL 250500)C轴、梁(KL 250500)D轴上的荷载为梯形荷载。恒载:5.12X3/2=7.68KN/m 活载:0.5X3/2=0.75KN/m若化为均布荷载3/2X4.2=0.357 恒载:(1-2X+)X7.68=6.07KN/m 活载:(1-2X+)X0.75=0.593KN/m(2)梁(KL 250500)传给边柱(KZ-1)的集中荷载为:恒载梁自重+女儿墙自重+ B1传荷载2=(2.64+4.5)X(4.2+4.2)/2+6.72X4.2X2/2=58.212KN活载=B1传荷载2=0.656X4.2X2/2=2.755KN由于梁的形心与柱的形心不一致,因此梁传给柱的集中荷载可向柱形心简化为一个集中荷载与一个力矩恒荷载作用下X(0.25-0.125)=58.212X0.125=7.28KN.M活荷载作用下X(0.25-0.125)=2.755X0.125=0.344KN.M梁(KL 250500)传给中柱(KZ-1)的集中荷载为:恒载梁自重 + B1传荷载2+ B2传荷载2=2.64X(4.2+4.2)/2+6.72X4.2X2/2+6.07x4.2x2/2=64.81KN活载=B1传荷载2 + B2传荷载2=0.656X4.2X2/2+0.593x4.2x2/2=5.25KN由于梁的形心与柱的形心不一致,因此梁传给柱的集中荷载可向柱形心简化为一个集中荷载与一个力矩恒荷载作用下X(0.25-0.125)=64.81x0.125=8.1KN.M活荷载作用下X(0.25-0.125)=8.1x0.125=1.01KN.M恒荷载受荷总图如图所示,活荷载受荷总图如图所示恒荷载受荷总图 活荷载受荷总图4.2梁柱线刚度比梁固端弯矩取4轴框架作为计算框架,考虑到楼板对梁的作用,边框架梁I=1.5I0 中框架梁I=2.0I0 (I0为不考虑楼板作用的梁截面惯性矩),梁柱均采用C30混凝土=3.0 AC,DF跨梁选用L3:b=250mm,h=700mm I0=1/12bh3=1/120.25.0.73=7.1410-3m4 i=EI/L=1.5EI0/L=1.57.1410-3E/7.8=1.3710-3E(m3)CD跨梁选用L2: b= 250mm, h=400mm I0=1/12bh3=1/120.250.43=1.3410-3m4 i=2EI/L=2EI0/L=21.3410-3E/3=0.8910-3E(m3) 上部各层柱: i=0.9xEI/L=0.9xE/3.61/120.50.53=1.3110-3E(m3)(0.9折减)底层柱: i=EI/L=E/(4.2+0.45+0.5)1/120.50.53=1.0110-3E(m3) 梁柱线刚度比图4.3恒荷载作用下内力计算顶层:AC 跨 =9.4x2+4.1= 22.9KN/m = 116.103 CG跨 =4.8X2+1.94=11.54KN/m =8.655 GC跨中 = 4.328 考虑偏心距的影响 =-116.103+7.28=108.823 =-8.655-8.1=16.755 = 4.328中间层:AC 跨 =7.33X2+4.1=18.76 KN/m =-95.113 CG跨 =4.74X2+1.94=11.42 KN/m =-8.565 GC跨中 =- 4.283 考虑偏心距的影响 =-95.113+5.61=-89.503 =-8.565-9.63=-18.195 = -4.2834.3.1弯矩分配系数1.远端固定S=4i (i=EI/L) 远端滑动S=i远端固定(中间柱)4x0.9EI/L远端固定梁 远端滑动梁 2. 系数 C=1/2 C=-13. 顶层 节点A = 0.489 =0.511 节点C = 0.384 =0.249 0.367标准层 节点A =+=0.328 = 0.328 +=0.344 节点C +=0.281 += 0.182 +=0.268 =0.268 底层 节点A =+=0.274 = 0.355 +=0.371 节点C +=0.299 += 0.194 +=0.221 =0.286分层法分配系数及恒载作用下固端弯矩计算结果(kN/m)节点单元ACG分配 系数位置A下柱A上柱AC端CA端C下柱C上柱CG端GC端顶层0.489-0.5110.3840.367-0.249-中间层0.3280.3280.3440.2810.2680.2680.182-底层0.2740.3550.3710.2990.2210.2860.194-固端 弯矩顶层-108.823108.823-16.755-4.328中间层-89.50389.503-18.195-4.283底层-89.50389.503-18.195-4.2834.3.2各层弯矩分配过程顶层弯矩分配过程弯矩分配法计算过程弯矩计算过程,并调整一次中间层弯矩分配过程:底层弯矩分配:4.3.3跨中弯矩计算顶层1/8x22.9x-(65.048+94.405)/2=94.428KN.m1/8x1.94x3x3+1/12x9.6 x3x3-48.142=-38.7595KN.m标准层1/8x18.76x-(66.898+82.078)/2=68.1818KN.m1/8x1.94x3x3+1/12x7.482x3x3-34.366=-26.572KN.m底层1/8x18.76x-(64.793+81.577)/2=69.4848KN.m=1/8x1.94x3x3+1/12x7.482 x3x3-35.736=-27.942KN.m4.3.4不平衡弯矩分配计算过程见如下(单位:kNm),方框内为原不平衡弯矩左梁上柱下柱右梁3.055.7011.15-5.70-5.03-7.941.9821.685.656.56-15.42-5.415.6511.15-11.29-5.41-7.944.2511.153.844.46-7.94-3.683.8411.15-7.67-3.68-7.942.8911.154.014.65-7.94-3.834.0112.18-8.03-3.83-8.623.0111.157.202.37-7.94-5.66-3.06-4.141.751.54不平衡弯矩调整之后即可得出恒荷载作用下框架弯矩图,(单位:kNm,括号内为调幅后的弯矩值). 将分层法得到的弯矩叠加后进行结点不平衡弯矩分配,考虑固端的塑性作用,对梁上弯矩进行调幅,调幅系数为,取0.8.又考虑荷载最不利位置,将跨中弯矩乘以1.1最终弯矩.4.3.5剪力计算=(70.75-97.46)/2+1/2X(4.1X7.8+14.66X7.8)=-13.355+1/2X146.33=59.81KN=146.33-59.81=86.52KN=1/2X(1.94X3+7.48X1.5)=8.52KN=(78.19-88.64)/2+1/2X146.33=-5.225+73.165=67.94KN=146.33-67.94=78.39KN=1/2X(1.94X3+7.48X1.5)=8.52KN=(74.57-86.54)/2+1/2X146.33=-5.985+73.165=67.18KN=146.33-61.20=85.13KN=1/2X(1.94X3+7.48X1.5)=8.52KN=(74.93-86.73)/2+1/2X146.33=-5.9+73.165=67.265KN=146.33-61.37=84.96KN=1/2X(1.94X3+7.48X1.5)=8.52KN=(68.79-83.95)/2+1/2X146.33=-7.58+73.165=65.585KN=146.33-65.585KN=80.745KN=1/2X(1.94X3+7.48X1.5)=8.52KN4.3.6轴力计算 柱的轴力:顶层柱轴力由点剪力和点集中力叠加得到,柱底轴力等于柱顶轴力,其余层轴力计算同顶层但要考虑该层上部柱轴力的传递。柱:6.93x3.6=24.95KN 58.212+59.81=118.022KN118.022+24.95=142.97KN118.022+44.86+67.98=230.86KN230.86+24.95=255.81KN230.86+44.86+67.18=342.9KN342.9+24.95=367.85KN342.9+44.86+67.27=455.03KN455.03+24.95=479.98KN455.03+44.86+65.585=565.475KN565.475+(X25X5.15+0.02X0.5X4X5.15X17)=565.475+35.69=601.165KN64.81+86.52+8.52=159.85KN159.85+24.95=184.8KN159.85+77.03+78.39+8.52=323.79KN323.79+24.95=348.74KN323.79+77.03+85.13+8.52=494.47KN494.47+24.95=519.42KN494.47+77.03+84.96+8.52=664.98KN664.98+24.95=689.93KN664.98+77.03+80.75+8.52=831.28KN831.28+35.69=866.97KN