ST6015矩形格构式基础计算书计算依据:1、《塔式起重机混凝土基础工程技术规程》JGJ/T187-20092、《混凝土结构设计规范》GB50010-20103、《建筑桩基技术规范》JGJ94-20084、《建筑地基基础设计规范》GB50007-20115、《钢结构设计规范》GB50017-2003一、塔机属性1、塔机传递至基础荷载标准值2、塔机传递至基础荷载设计值承台及其上土的自重荷载标准值:G k=bl(hγc+h'γ')=4.6×4.6×(1.4×25+0×19)=740.6kN承台及其上土的自重荷载设计值:G=1.35G k=1.35×740.6=999.81kN桩对角线距离:L=(a b2+a l2)0.5=(32+32)0.5=4.243m1、荷载效应标准组合轴心竖向力作用下:Q k=(F k+G k+G p2)/n=(695+740.6+20)/4=363.9kN荷载效应标准组合偏心竖向力作用下:Q kmax=(F k+G k+G p2)/n+(M k+F Vk h)/L=(695+740.6+20)/4+(4647+156×30.9)/4.243=2595.099kN Q kmin=(F k+G k+G p2)/n-(M k+F Vk h)/L=(695+740.6+20)/4-(4647+156×30.9)/4.243=-1867.499kN2、荷载效应基本组合荷载效应基本组合偏心竖向力作用下:Q max=(F+G+1.35×G p2)/n+(M+F v h)/L=(938.25+999.81+1.35×20)/4+(6273.45+210.6×30.9)/4.243=3503.518kN Q min=(F+G+1.35×G p2)/n-(M+F v h)/L=(938.25+999.81+1.35×20)/4-(6273.45+210.6×30.9)/4.243=-2520.988kN 四、格构柱计算整个格构柱截面对X、Y轴惯性矩:I=4[I0+A0(a/2-Z0)2]=4×[1881.12+61.95×(51.00/2-5.13)2]=110345.844cm4整个构件长细比:λx=λy=H0/(I/(4A0))0.5=390/(110345.844/(4×61.95))0.5=18.482 分肢长细比:λ1=l01/i y0=30.00/3.53=8.499分肢毛截面积之和:A=4A0=4×61.95×102=24780mm2格构式钢柱绕两主轴的换算长细比:λ0 max=(λx2+λ12)0.5=(18.4822+8.4992)0.5=20.342 λ0max=20.342≤[λ]=150满足要求!2、格构式钢柱分肢的长细比验算λ1=8.499≤min(0.5λ0max,40)=min(0.5×20.342,40)=10.171满足要求!3、格构式钢柱受压稳定性验算λ0max(f y/235)0.5=20.342×(345/235)0.5=24.647查表《钢结构设计规范》GB50017附录C:b类截面轴心受压构件的稳定系数:υ=0.953Q max/(υA)=2039.426×103/(0.953×24780)=86.36N/mm2≤f=295N/mm2满足要求!4、缀件验算缀件所受剪力:V=Af(f y/235)0.5/85=24780×295×10-3×(345/235)0.5/85=104.203kN 格构柱相邻缀板轴线距离:l1=l01+30=30.00+30=60cm作用在一侧缀板上的弯矩:M0=Vl1/4=104.203×0.6/4=15.63kN·m分肢型钢形心轴之间距离:b1=a-2Z0=0.51-2×0.0513=0.407m作用在一侧缀板上的剪力:V0=Vl1/(2·b1)=104.203×0.6/(2×0.407)=76.733kNσ= M0/(bh2/6)=15.63×106/(16×3002/6)=65.127N/mm2≤f=215N/mm2满足要求!τ=3V0/(2bh)=3×76.733×103/(2×16×300)=23.979N/mm2≤τ=125N/mm2满足要求!角焊缝面积:A f=0.7h f l f=0.8×8×620=3472mm2角焊缝截面抵抗矩:W f=0.7h f l f2/6=0.7×8×6202/6=358773mm3垂直于角焊缝长度方向应力:σf=M0/W f=15.63×106/358773=44N/mm2平行于角焊缝长度方向剪应力:τf=V0/A f=76.733×103/3472=22N/mm2((σf /1.22)2+τf2)0.5=((44/1.22)2+222)0.5=42N/mm2≤f tw=200N/mm2满足要求!根据缀板的构造要求缀板高度:300mm≥2/3 b1=2/3×0.407×1000=272mm满足要求!缀板厚度:16mm≥max[1/40b1,6]= max[1/40×0.407×1000,6]=10mm满足要求!缀板间距:l1=600mm≤2b1=2×0.407×1000=815mm满足要求!线刚度:∑缀板/分肢=4×16×3003/(12×(510-2×51.3))/(1881.12×104/600)=11.274≥6满足要求!五、桩承载力验算1、桩基竖向抗压承载力计算桩身周长:u=πd=3.14×0.9=2.827m桩端面积:A p=πd2/4=3.14×0.92/4=0.636m2承载力计算深度:min(b/2,5)=min(4.6/2,5)=2.3mf ak=(2×0+0.3×85)/2.3=25.5/2.3=11.087kPa承台底净面积:A c=(bl-nA p)/n=(4.6×4.6-4×0.636)/4=4.654m2复合桩基竖向承载力特征值:R a=uΣq sia·l i+q pa·A p+εc f ak A c=2.827×(1.9×17.5+4×22.5+3×25+12×22.5+11.2×25+2×32.5)+600×0.636+0.1×11.087×4.654=2686.273kNQ k=363.9kN≤R a=2686.273kNQ kmax=2595.099kN≤1.2R a=1.2×2686.273=3223.528kN满足要求!2、桩基竖向抗拔承载力计算Q kmin=-1867.499kN<0按荷载效应标准组合计算的桩基拔力:Q k'=1867.499kN桩身位于地下水位以下时,位于地下水位以下的桩自重按桩的浮重度计算,桩身的重力标准值:G p=(l t-(H0-h r-h/2))×(γz-10)×A p=(60.2-(30.6-3.8-1.4/2))×(25-10)×0.636 =325.402kNR a'=uΣλi q sia l i+G p=2.827×(0.75×1.9×17.5+0.75×4×22.5+0.75×3×25+0.75×12×22.5+0.75×11.2×25+0.75×2×32.5)+325.402=2049.96kNQ k'=1867.499kN≤R a'=2049.96kN满足要求!3、桩身承载力计算纵向普通钢筋截面面积:A s=nπd2/4=16×3.142×252/4=7854mm2(1)、轴心受压桩桩身承载力荷载效应基本组合下的桩顶轴向压力设计值:Q=Q max=3503.518kNψc f c A p+0.9f y'A s'=(0.75×17×0.636×106 + 0.9×(360×7853.982))×10-3=10795.494kN Q=3503.518kN≤ψc f c A p+0.9f y'A s'=10795.494kN满足要求!(2)、轴心受拔桩桩身承载力荷载效应基本组合下的桩顶轴向拉力设计值:Q'=-Q min=2520.988kNf y A S=360×7853.982×10-3=2827.433kNQ'=2520.988kN≤f y A S=2827.433kN满足要求!4、桩身构造配筋计算A s/A p×100%=(7853.982/(0.636×106))×100%=1.235%≥0.45%满足要求!六、承台计算承台有效高度:h0=1400-50-25/2=1338mmM=(Q max+Q min)L/2=(3503.518+(-2520.988))×4.243/2=2084.437kN·mX方向:M x=Ma b/L=2084.437×3/4.243=1473.795kN·mY方向:M y=Ma l/L=2084.437×3/4.243=1473.795kN·m2、受剪切计算V=F/n+M/L=938.25/4 + 6273.45/4.243=1713.229kN受剪切承载力截面高度影响系数:βhs=(800/1338)1/4=0.879塔吊边缘至角桩内边缘的水平距离:a1b=(a b-B-d)/2=(3-2-0.9)/2=0.05ma1l=(a l-B-d)/2=(3-2-0.9)/2=0.05m 剪跨比:λb'=a1b/h0=50/1338=0.037,取λb=0.25;λl'= a1l/h0=50/1338=0.037,取λl=0.25;承台剪切系数:αb=1.75/(λb+1)=1.75/(0.25+1)=1.4αl=1.75/(λl+1)=1.75/(0.25+1)=1.4βhsαb f t bh0=0.879×1.4×1.57×103×4.6×1.338=11895.977kNβhsαl f t lh0=0.879×1.4×1.57×103×4.6×1.338=11895.977kNV=1713.229kN≤min(βhsαb f t bh0,βhsαl f t lh0)=11895.977kN满足要求!3、受冲切计算塔吊对承台底的冲切范围:B+2h0=2+2×1.338=4.676ma b=3m≤B+2h0=4.676m,a l=3m≤B+2h0=4.676m角桩位于冲切椎体以内,可不进行角桩冲切的承载力验算!4、承台配筋计算(1)、承台底面长向配筋面积αS1= M y/(α1f c bh02)=1473.795×106/(1.03×16.7×4600×13382)=0.01δ1=1-(1-2αS1)0.5=1-(1-2×0.01)0.5=0.01γS1=1-δ1/2=1-0.01/2=0.995A S1=M y/(γS1h0f y1)=1473.795×106/(0.995×1338×300)=3691mm2最小配筋率:ρ=max(0.2,45f t/f y1)=max(0.2,45×1.57/300)=max(0.2,0.236)=0.236% 梁底需要配筋:A1=max(A S1, ρbh0)=max(3691,0.0024×4600×1338)=14495mm2 承台底长向实际配筋:A S1'=15545mm2≥A1=14495mm2满足要求!(2)、承台底面短向配筋面积αS2= M x/(α2f c bh02)=1473.795×106/(1.03×16.7×4600×13382)=0.01δ2=1-(1-2αS2)0.5=1-(1-2×0.01)0.5=0.01γS2=1-δ2/2=1-0.01/2=0.995A S2=M x/(γS2h0f y1)=1473.795×106/(0.995×1338×300)=3691mm2最小配筋率:ρ=max(0.2,45f t/f y1)=max(0.2,45×1.57/300)=max(0.2,0.236)=0.236% 梁底需要配筋:A2=max(9674, ρlh0)=max(9674,0.0024×4600×1338)=14495mm2 承台底短向实际配筋:A S2'=15545mm2≥A2=14495mm2满足要求!(3)、承台顶面长向配筋面积承台顶长向实际配筋:A S3'=12038mm2≥0.5A S1'=0.5×15545=7773mm2满足要求!(4)、承台顶面短向配筋面积承台顶长向实际配筋:A S4'=12038mm2≥0.5A S2'=0.5×15545=7773mm2满足要求!(5)、承台竖向连接筋配筋面积承台竖向连接筋为双向Φ10@500。