塔吊基础设计

塔吊基础设计（四桩）计算书工程名称：坪山聚龙山保障性住房编制单位：中建四局计算参数（1）基本参数采用1台TC6013-6塔式起重机，塔身尺寸1.80m,基坑底标高-11.25m；现场地面标高0.00m,承台面标高-9.90m。（2）计算参数1）塔吊基础受力情况:何载工况基础荷载P(kN)M(kN.m)FkFhMMz工作状态684.5022.82152.00402.00非工作状态624.5097.02695.100MFk=MFk=基础顶面所受垂直力F：=基础顶面所受水平力M=基础顶面所受倾覆力矩MMz=基础所受扭矩塔吊基础受力示意图比较塔吊的工作状态和非工作状态的受力情况，塔吊基础按非工作状态计算如图：Fk=624.50kN,Fh=97.00kN,M=2695.10+97.00X1.25=2816.35kN.mFk，=624.50X1.35=843.08kN,F『=97.00X1.35=130.95kN,M「(2695.10+97.00X1.25)X1.35=3802.07kN.m2）桩顶以下岩土力学资料

序号地层名称厚度L(m)极限侧阻力标准值qsik(kPa)岩石饱和单轴抗压强度标准值frk(kPa)q*sik*i(kN/m)抗拔系数入i入.q.*'.(kN/m)11填土2.6920.0053.800.4043.042淤泥层1.2012.0014.400.304.323粘土层0.8053.0042.400.4016.964粗砂层1.4074.00103.600.5051.805砾质粘性土3.40135.00459.000.70321.306强风化岩0.60140.0084.000.7058.807中风化岩2.10180.0015000.00378.000.70264.608微风化岩1.81240.0030000.00434.400.70304.08桩长14.00Gsik*Li1569.60以iisikL1064.90(3)基础设计主要参数基础桩采用4根？800钻(冲)孔灌注桩，桩顶标高-11.15m,桩端不设扩大头，桩端入微风化岩1.81m；桩混凝土等级C35,f「16.70N/mm2,E「3.15X104N/mm2；ft=1.57N/mm2,桩长14.00m；钢筋HRB335,f「300.00N/mm2,Es=2.00X105N/mm2；承台尺寸长(a)=9.80m,宽(b)=9.80m,高(h)=1.35m,桩中心与承台中心4.00m,承台面标高-9.90m；承台混凝土等级C35,ft=1.57N/mm2,f「16.70N/mm2,y砼=25kN/m3。Gk=aXbXhXy砼=9.80X9.80X1.35X25=3241.35kN

承台90Q.900190承台90Q.900190G[刖叩[&00&BDOIo昌

ODOm桩顶作用效应计算竖向力轴心竖向力作用下Nk=(Fk+Gk)/n=(624.50+3241.35)/4=966.46kN偏心竖向力作用下按照Mx作用在对角线进行计算，Mx=Mk=2816.35kN.myf4.OOX20B5.66mNk=(Fk+Gk)/n+Mxyi/Zy：=(624.50+3241.35)/4±(2816.35X5.66)/(2X5.662)=966.46±248.79Nkmax=1215.25kN,Nkmin=717.67kN(基桩不承受竖向拉力)。水平力Hik=Fh/n=97.00/4=24.25kN3：桩基竖向承载力验算(1)单桩竖向极限承载力标准值计算d=0.80m=800mm,h=1.81m,h/d=1.81/0.80=2.26，查表得：，=0.93A=nd2/4=3.14XO.8O2/4=0.50m2Qk=u£q.k'=nd£q.」=3.14X0.80X1569.60=3942.84kNQrk=：rfrkA=0.93X30000.00X0.50=13950.00kNQuk=Qsk+Qrk=3942.84+13950.00=17892.84kNR=1/KQ=1/2X17892.84=8946.42kN(2)桩基竖向力作用下轴心竖向力作用下Nk=966.46kNVR「8946.42kN,竖向承载力满足要求。偏心竖向力作用下Nkmax=1215.25kNVR「1.2X8946.42=10735.70kN，竖向承载力满足要求。单桩水平承载力验算单桩水平承载力特征值计算aE=Es/Ec=2.00X105/3.15X104=6.35,ym=2,：n=0.50p=0.2+(2000-800)/(2000-300)X(0.65-0.2)=0.52%Wo=nd/32[d2+2(E/EC—1)p"]=(3.14X0.80/32)X[0.802+2X(6.35-1)X0.52%X(0.80-2X0.10)2]=0.05m3Io=Wod/2=0.05X0.80/2=0.0200m4EI=0.85ECIo=0.85X3.15X107X0.0200=535500kN.m2查表得:m=6.00X103kN/m4,b=0.9(1.5d+0.5)=1.53m=1530mma=(mbo/EcI)0.2=(6.00X1000X1.53/535500)o.2=0.44aL=0.44X14.00=6.16>4,按aL=4,查表得：um=0.768Nk=(F「+1.2Gk)/n=(843.08+1.2X3241.35)/4=1183.18kN,An=nd2/4[1+(Es/Ec-1)Pg]=3.14X0.802/4X(1+(6.35-1)X0.52%)=0.52m2R=(0.75aYfW/u)(1.25+22p)(1+：N/yfA)hamt0mgNkmtn=(0.75X0.44X2X1.57X1000X0.05/0.768)X(1.25+22X0.52%)X[1+0.50X1183.18/(2X1.57X1000X0.52)]=125.39kN桩基水平承载力计算Hik=24.25kNVRha=125.39kN,水平承载力满足要求。抗拔桩基承载力验算抗拔极限承载力标准值计算Tgk=1/nu1Z入iqsikLi=1/4X(4.00X2+0.80)X4X1064.90=9371.12kNTuk=Z入iqsikUiLi=1064.90X3.14X0.80=2675.03kN抗拔承载力计算G=9.80X9.80X13.90X(18.80-10)/4=2936.90kNG=0.50X14.00X(25-10)=105.00kNpTgk/2+Ggp=9371.12/2+2936.90=7622.46kNTuk/2+Gp=2675.03/2+105.00=1442.52kN由于基桩不承受竖向拉力，故基桩呈整体性和非整体性破坏的抗拔承载力满足要求。抗倾覆验算

b,=9.80/2+4.00=8.90ma,=9.80/2=4.90m倾覆力矩M倾=M+Fhh=2695+97.00X1.25=2816.35kN・m抗倾覆力矩M抗二(Fk+Gk)ai+2(Tuk/2+Gp)bi=(624.50+3241.35)X4.90+2X(2675.03/2+105.00)X8.90=44619.43kN・mM抗/M倾=44619.43/2816.35=15.84抗倾覆验算15.84>1.6,满足要求。(1)桩身承载力验算1)正截面受压承载力计算按照Mx作用在对角线进行计算，M「Mk=3802.07kN.m,yi=4.00X20.5=5.66mNk=(Fk‘+1.2Gk)/n+Mxyi/Zyi2=(843.08+1.2X3241.35)/4±(3802.07X5.66)/(2X5.66^)=1183.18+335.87kmax=1519.05kN,Nkmax=847.31kNkmaxWc=0.70WcfcAp=0.70X16.70X1000X0.50=5845.00kN正截面受压承载力=5845.00kN>Nkma「1519.05kN,满足要求。2)配筋计算配筋率p=pg=0.52%As=pAP=0.52%X0.50X106=2600mm2,采用HRB335,f「300.00N/mm2取822A1=8X380=3040mm2>A=2600mm2(满足要求)正截面受拉承载力计算fA=300X3040=912000N=912.00kNysfyAs=912.00kN>Nkmin=847.31kN,正截面受拉承载力满足要求。M倾/(4妇A)=2816.35X1000/(4X4.00X3040)=57.90N/mm2M倾/(4x1As)=57.90N/mm2V300.00N/mm2,满足要求。(2)承台受冲切承载力验算塔身边冲切承载力计算F=F-1.2ZQik=Fk，=843.08kN,h「1.35-0.10=1.25m=1250mmPhp=1.0+(2000-1350)/(2000-800)X(0.9-1.0)=0.95a0=4.00-0.80/2-1.80/2=2.70m,入=a0/h°=2.70/1.25=2.16，入>1.0,A=1.0P0=0.84/(1.00+0.2)=0.70,Um=4X(1.80+1.25)=12.20mPhpP0Umfth「0.95X0.70X12.20X1.57X1000X1.25=15921.76kN承台受冲切承载力=15921.76kN>Ft=843.08kN,满足要求。角桩向上冲切力承载力计算N1=Nk，=Fk，/n+Mxyi/Zyi2=843.08/4+3802.07X5.66/(2X5.662)=546.64kNA1x=A1y=a0/h「2.70/1.25=2.16,A>1.0,A=1.0,c1=c2=0.90+0.40=1.30mP1x=P1y=0.56/(A1x+0.2)=0.56/(1.00+0.2)=0.47[P(c+a/2)+P(c+a/2)]pfh=0.47X(1.30+2.70/2)X2X0.95X1.57X1000X1.25=1x21y1y11xhpto4644.16kN角桩向上冲切承载力=4644.16kN>2N「1093.28kN,满足要求。承台受剪切承载力验算Nk，=Fk，/n+Mxyi/Zyi2=843.08/4+3802.07X5.66/(2X5.662)=546.64kNV=2Nk，=2X546.64=1093.28kNPhs=(800/ho)1/4=(800/1250)0.25=0.89,A=a0/h「2.70/1.25=2.16a=1.75/(A+1)=1.75/(2.16+1)=0.55,b0=9.80m=9800mmPhsaftb0ho=0.89X0.55X1.57X1000X9.80X1.25=9414.31kN承台受剪切承载力=9414.31kN>2N「1093kN,满足要求。(4)承台抗弯验算承台弯矩计算Ni=Fk/n+Mxyi/Zyi2=843.08/4+3802.07X5.66/(2X5.662)=546.64kN,xi=3.10mM=ZNixi=2X546.64X3.10=3389.18kN.m承台配筋计算承台采用HRB335，f=300.00N/mm2yAs=M/0.9fho=3389.18X106/(0.9X300X1250)=10042mm2取4922@199mm(钢筋间距满足要求)，A=49X380=18620mm2s承台配筋面积18620mm2>12250mm2,满足要求。

承台弯矩示意图计算结果(1)基础桩钻(冲)孔4根？800灌注桩，桩顶标高-11.15m,桩长14.00m,