四樁承臺(tái)計(jì)算書1.doc

四 樁 承 臺(tái) 計(jì) 算 書一、示意圖：二、基本資料：承臺(tái)類型：四樁承臺(tái)承臺(tái)計(jì)算方式：驗(yàn)算承臺(tái)尺寸1依據(jù)規(guī)范：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范（GB 500102002）2幾何參數(shù)：承臺(tái)邊緣至樁中心距: C = 550 mm 樁列間距: A = 1800 mm樁行間距: B = 1800 mm承臺(tái)根部高度: H = 700 mm承臺(tái)端部高度: h = 700 mm 縱筋合力點(diǎn)到底邊的距離: as = 70 mm 平均埋深: hm = 2.50 m 矩形柱寬: Bc = 500 mm 矩形柱高: Hc = 500 mm 圓樁直徑: Ds = 533 mm 換算后樁截面：Ls = 426mm3荷載設(shè)計(jì)值：(作用在承臺(tái)頂部）豎向荷載: F = 3170.00 kN 繞X軸彎矩: Mx = 413.00 kNm繞Y軸彎矩: My = 413.00 kNmX向剪力: Vx = 0.00 kN Y向剪力: Vy = 0.00 kN4材料信息：混凝土強(qiáng)度等級: C30fc = 14.30 N/mm2ft = 1.43 N/mm2鋼筋強(qiáng)度等級: HRB335fy = 300.00 N/mm2三、計(jì)算過程：1作用在承臺(tái)底部的彎矩繞X軸彎矩: M0x = MxVyH = 413.000.000.70 = 413.00kNm繞Y軸彎矩: M0y = MyVxH = 413.000.000.70 = 413.00kNm2基樁凈反力設(shè)計(jì)值：計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）Ni = F/nM0xyi/yj2M0yxi/xj2 （8.5.32）N1 = F/nM0xy1/yj2M0yx1/xj2 = 3170.00/4413.000.90/3.24413.00(-0.90)/3.24 = 563.06 kNN2 = F/nM0xy2/yj2M0yx2/xj2 = 3170.00/4413.000.90/3.24413.000.90/3.24 = 792.50 kNN3 = F/nM0xy3/yj2M0yx3/xj2 = 3170.00/4413.00(-0.90)/3.24413.00(-0.90)/3.24 = 792.50 kNN4 = F/nM0xy4/yj2M0yx4/xj2 = 3170.00/4413.00(-0.90)/3.24413.000.90/3.24 = 1021.94 kN3承臺(tái)受柱沖切驗(yàn)算：計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）Fl 20x(bca0y)0y(hca0x)hpfth0 （8.5.171）X方向上自柱邊到最近樁邊的水平距離：a0x = 0.44 my方向上自柱邊到最近樁邊的水平距離：a0y = 0.44 m承臺(tái)有效高度：h0 = Has = 0.700.07 = 0.63 m作用于沖切破壞錐體上的沖切力設(shè)計(jì)值： Fl = FQi = 3170.000.00 = 3170.00 kNX方向沖跨比：0x = a0x/h0 = 0.44/0.63 = 0.69 Y方向沖跨比：0y = a0y/h0 = 0.44/0.63 = 0.69 X方向沖切系數(shù)：0x = 0.84/(0x0.2) = 0.84/(0.690.2) = 0.94 Y方向沖切系數(shù)：0y = 0.84/(0y0.2) = 0.84/(0.690.2) = 0.94 20x(Hca0y)0y(Bca0x)hpfth0 = 20.94(0.500.44)0.94(0.500.44)1.001430.000.63 = 3174.31 kN Fl = 3170.00 kN, 滿足要求。4承臺(tái)受剪驗(yàn)算：計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）Fl hsftb0h0 （8.5.181）(1) 垂直Y方向截面的抗剪計(jì)算Y方向上自柱邊到計(jì)算一排樁的樁邊的水平距離：a0 = 0.44 m計(jì)算截面處承臺(tái)寬度：b = A2C = 1.8020.55 = 2.90 m 斜截面上最大剪力設(shè)計(jì)值：Vl = 1814.44 kN計(jì)算截面的剪跨比： a0/h0 = 0.44/0.63 = 0.69剪切系數(shù)： = 1.75/(1.0) = 1.75/(0.691.0) = 1.03承臺(tái)計(jì)算截面的計(jì)算寬度：be = b = 2.90 m hsftbeh0 = 1.001.031430.002.900.63 = 2700.04 kN Vl = 1814.44 kN, 滿足要求。(2) 垂直X方向截面的抗剪計(jì)算X方向上自柱邊到計(jì)算一排樁的樁邊的水平距離：a0 = 0.44 m計(jì)算截面處承臺(tái)寬度：b = B2C = 1.8020.55 = 2.90 m 斜截面上最大剪力設(shè)計(jì)值：Vl = 1814.44 kN計(jì)算截面的剪跨比： a0/h0 = 0.44/0.63 = 0.69剪切系數(shù)： = 1.75/(1.0) = 1.75/(0.691.0) = 1.03承臺(tái)計(jì)算截面的計(jì)算寬度：be = b = 2.90 m hsftbeh0 = 1.001.031430.002.900.63 = 2700.04 kN Vl = 1814.44 kN, 滿足要求。5承臺(tái)角樁沖切驗(yàn)算：計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）Nl 1x(c2a1y/2)1y(c1a1x/2)hpfth0（8.5.175）角樁豎向沖反力設(shè)計(jì)值：Nl = 1021.94 kN從角樁內(nèi)邊緣至承臺(tái)外邊緣的距離：c1 = CLs/2 = 0.550.43/2 = 0.76 mc2 = CLs/2 = 0.550.43/2 = 0.76 mX方向上從承臺(tái)角樁內(nèi)邊緣引45度沖切線與承臺(tái)頂面相交點(diǎn)至角樁內(nèi)邊緣的水平距離:（當(dāng)柱或承臺(tái)變階處位于該45度線以內(nèi)時(shí)，則取由柱邊或變階處與樁內(nèi)邊緣連線為沖切錐體的錐線）a1x = 0.44 mY方向上從承臺(tái)角樁內(nèi)邊緣引45度沖切線與承臺(tái)頂面相交點(diǎn)至角樁內(nèi)邊緣的水平距離:（當(dāng)柱或承臺(tái)變階處位于該45度線以內(nèi)時(shí)，則取由柱邊或變階處與樁內(nèi)邊緣連線為沖切錐體的錐線）a1y = 0.44 mX方向角樁沖跨比：1x = a1x/h0 = 0.44/0.63 = 0.69y方向角樁沖跨比：1y = a1y/h0 = 0.44/0.63 = 0.69X方向角樁沖切系數(shù)：1x = 0.56/(1x0.2) = 0.56/(0.690.2) = 0.63Y方向角樁沖切系數(shù)：1y = 0.56/(1y0.2) = 0.56/(0.690.2) = 0.631x(c2a1y/2)1y(c1a1x/2)hpfth0 = 0.63(0.760.44/2)0.63(0.760.44/2)1.001430.000.63 = 1108.70 kN Nl = 1021.94 kN, 滿足要求。6承臺(tái)受彎計(jì)算：計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）Mx Niyi（8.5.161）計(jì)算公式：建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范（GB 500072002）My Nixi（8.5.162）(1) 垂直X軸方向計(jì)算截面處彎矩計(jì)算：My Nixi = 1179.39 kNm相對受壓區(qū)高度：= 0.074424 配筋率：= 0.003548X向鋼筋: Asx = 6481.34 mm2(2) 垂直Y軸方向計(jì)算截面處彎矩計(jì)算：Mx = Niyi = 1179.39 kNm相對受壓區(qū)高度：= 0.074424 配筋率：= 0.003548Y向鋼筋: Asy = 6481.34 mm27承臺(tái)受壓驗(yàn)算：計(jì)算公式：混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范（GB 500102002）Fl 1.35clfcAln （7.8.11）局部荷載設(shè)計(jì)值：Fl = Fc = 3170.00 kN混凝土局部受壓面積：Al = BcHc = 0.500.50 = 0.25m2混凝土局部受壓計(jì)算面積：Ab = 2.25 m2混凝土受壓時(shí)強(qiáng)度提高系數(shù)：l = sq.(Ab/Al) = sq.(2.25/0.25) = 3.00 1.35clfcAl =