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某大学建筑结构毕业设计

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'某大学建筑结构毕业设计结构部分一.工程概况本工程共10层(不包括一层地下室)。地下室层高为3.6m,1~4层层高为3.6m,5~10层层高为3.0m,局部楼梯间出屋面部分层高为3.3m,建筑总高为32.4m(不包括出屋面部分)。三进深分别为6.6m、2.4m、6.6m。总宽15.6m(局部突出1.5m不在总宽之内)。纵向每个柱距均为7.8m,共7个柱距,总长54.6m。本工程结构方案经过分析比较,采用纯框架结构体系,因为建筑物上部结构荷载对称,平面布局简单,受力比较均匀,且房屋总高度不超过6度抗震设防时的55m高度的限值;采用框架结构体系的优点可以使结构布置灵活,使用方便,不足的是抗震能力较低刚度较小。本工程建于6度抗震设防区Ⅱ类场地土。根据规范查得,框架的抗震等级为三级。本工程框架材料选用如下:-1~4层柱采用C40混凝土;5~10层柱采用C30混凝土;框架梁采用C25混凝土。结构柱网布置见(图-1)。75 二.截面尺寸估算梁板截面尺寸估算框架梁截面高度h,按梁跨度的1/10~1/15确定,则横向框架梁高为6600×(1/10~1/15)=660~440,取h=600mm,梁宽取梁高的一半,即b=300mm;横向次梁高为6600×(1/8~1/15)=825~440,取h=500mm,梁宽b=250mm;纵向框架梁高为7800×(1/10~1/15)=780~520,取h=600mm,梁宽b=300mm。板的最小厚度为L/40=3900/40=97.5mm,考虑到板的挠度及裂缝宽度的限制及在板中铺设管线等因素,根据经验取板厚为120mm。柱截面尺寸估算根据柱支撑的楼板面积计算由竖向荷载作用下产生的轴力,并按轴压比控制估算柱截面面积,估算柱截面时,楼层荷载按11~14KN/m2计,本工程边柱按13KN/m2计,中柱按11KN/m2计。负荷面为7.8×6.6/2的边柱轴力:75 NV=(7.8×6.6/2)×13×11×1.25=4601KN,负荷面为7.8×(6.6+2.4)/2的边柱轴力:NV=[(6.6+2.4)/2]×7.8×11×11×1.25=5309KN,各柱的轴力虽然不同,但为了施工方便和美观,往往对柱截面进行合并归类。本工程将柱截面归并为一种。取轴力最大的柱估算截面面积。本工程框架为三级抗震,取N=1.1NV=1.1×5309=5840KN,柱轴压比控制值μN查规范得μN=0.9。其中μN=N/ACfC设柱为正方形,柱边长b=h=C=577mm。故本工程-1~4层柱截面取为600×600mm,5~10层柱截面取为500×500mm。5层底柱截面核算NV=[(6.6+2.4)/2]×7.8×11×6×1.25=2896KN,N=1.1×2896=3185KN,N/ACfC=3185000/5002/15=0.85<0.9柱轴压满足要求。柱高度:地上部分每层柱高均等于该层层高,地下部分柱高h=3.6+0.1=3.7m。三.荷载汇集竖向荷载楼面荷载楼面活荷载按荷载规范的规定,宿舍房间活荷载取1.5KN/m275 (标准值),厕所、走廊、楼梯间、教室活荷载取2.0KN/m2(标准值),本工程为简化计算,均取楼面活荷载为2.0KN/m2。砼楼板(板厚120),25×0.12=3.0KN/m2,水泥砂浆抹灰(楼板上下分别为40和20厚),20×(0.04+0.02)=1.2KN/m2,内隔墙为200厚陶粒砼砌块,砌块容重8KN/m3,两侧各抹20厚混合砂浆,8×0.2+20×0.02×2=2.4KN/m2,外墙为400厚陶粒砼砌块,墙外侧贴墙面砖,墙里侧抹混合砂浆,0.5+8×0.4+20×0.02×2=4.5KN/m2。屋面荷载30厚水泥花阶砖0.6KN/m2,25厚粗砂垫层17×0.025=0.425KN/m2,35厚苯板0.1KN/m2,防水卷材0.1KN/m2,20厚砂浆找平层20×0.02=0.4KN/m2,炉渣砼找坡2%(最薄处30厚)14×0.15=2.1KN/m2,120厚钢筋砼楼板25×0.12=3.0KN/m2,20厚混合砂浆抹灰20×0.02=0.4KN/m2,合计7.125KN/m2,上人屋面活荷1.5KN/m2,75 基本雪压0.4KN/m2,水平风荷载查荷载规范中全国基本风压分布图可知哈市基本风压值为0.45KN/m2。根据荷载规范规定,对于高层建筑结构,其基本风压可按基本风压分布图中数值乘以1.1后采用,即ω0=1.1×0.45=0.495KN/m2。垂直于建筑物表面上的风荷载标准值按ωK下式计算:ωK=βZ·μS·μZ·ω0风荷载体型系数μS,查荷载规范可知,矩形平面建筑μS=1.3,风压高度变化系数μZ,本工程建在某高校校区,地面粗糙度类别为C类,查荷载规范中μZ之值,5m以上按内插法计算,5m以下按5m高处取值。风振系数βZ,βZ=1+(Hi/H)×(ξV/μZ),式中V为脉动影响系数,当高层建筑的高宽比不小于2,地面粗糙度类别为C类时,V=0.63。式中ξ为脉动增大系数,与基本风压ω0,结构自振周期T及地面粗糙度有关。框架结构基本自振周期取T=0.09n=0.09×11=0.99,ω0×T2=0.495×0.992=0.485。查荷载规范,ξ=1.32。各层风荷载标准值计算结果见(表-1)。各层风荷载标准值表表-1距地面高度HIβZμZμSω0ωK=βZ·μS·μZ·ω075 34.081.7151.1631.3000.4951.28332.401.6931.1411.3000.4951.24329.401.6521.1001.3000.4951.16926.401.6141.0491.3000.4951.09023.401.5720.9981.3000.4951.01020.401.5260.9471.3000.4950.93017.401.4820.8801.3000.4950.83914.401.4330.8111.3000.4950.74810.801.3620.7281.3000.4950.6387.201.2860.6151.3000.4950.5093.601.1630.5401.3000.4950.40475 0.001.0000.5401.3000.4950.347四.水平荷载作用下框架内力及侧移计算由平面图可以看出,除边框架外,中间各榀框架受风面积相同,故应选取边框架和中间框架分别进行计算。下面仅以中框架为例进行计算,边框架计算从略。计算在风荷载作用下各楼层节点上集中力及各层剪力。计算在风荷载作用下各楼层节点上集中力时,假定风荷载在层间为均匀分布,并假定上下相邻各半层层高范围内的风荷载按集中力作用在本层楼面上。10层顶处风荷载作用下各楼层节点上集中力计算:F10=(ω10+1×h10+1+ω10×h10/2)×B=(1.283×1.68+1.243×3.0/2)×7.8=31.36KN9层顶处风荷载作用下各楼层节点上集中力计算:F9=(ω10×h10/2+ω9×h9/2)×B=(1.243×3.0/2+1.169×3.0/2)×7.8=28.22KN其余各层风荷载引起的节点集中力及各层剪力计算结果见(表-2)风荷载作用水平集中力及层剪力表表-2层号i层高hI75 (m)风荷标准值ωki各层集中力FI(KN)各层剪力VI=∑FI(KN)女儿墙3.01.283103.01.24331.3631.3693.01.16928.2259.5883.01.09026.4386.0173.01.01024.57110.5863.00.93022.70133.2853.00.83920.70153.9843.60.74820.32174.3033.60.63819.46193.7623.60.50916.10209.8613.60.40412.82222.69地下室3.60.3475.67228.36计算各梁柱的线刚度ib和ic,计算梁的线刚度时,考虑到现浇板的作用,一边有楼板的梁截面惯性矩取i=1.5i0,两边有楼板的梁截面惯性矩取i=2i0,i0为按矩形截面计算的梁截面惯性矩。线刚度计算公式i=EI/l。各梁柱线刚度计算结果见(表-3)。计算各柱抗侧移刚度D75 D值为使柱上下端产生单位相对位移所需施加的水平力,计算公式为:D=αC×(12ic/h2)各柱抗侧移刚度D见(表-4)各杆件惯性矩及线刚度表表-3b×h(mm)L(mm)EC(N/mm2)I0=bh3/12(mm4)I=2I0i=EI/L(N.mm)梁300×60066002.80×1045.40×1091.08×10104.58×1010300×60024002.80×1045.40×1091.08×10101.26×1011柱600×60036003.25×1041.08×10109.75×1010500×50030003.00×1045.21×1095.21×1010水平荷载作用下抗侧移刚度D及柱剪力Vij计算表表-4层/hi柱列轴号ic(×∑ib(×K=∑ib/2icαC=K/(2+K)Di=αC×(12ic/hi2)∑DiVij(KN)75 105)(KN.m)105)(KN.m)底层K=∑ib/ic底层αC=(0.5+K)/(2+K)(×105)10/3.0B0.5210.9160.8790.3050.2121288005.16C0.5213.4363.2980.6220.43212880010.52D0.5213.4363.2980.6220.43212880010.52E0.5210.9160.8790.3050.2121288005.169/3.0B0.5210.9160.8790.3050.2121288009.81C0.5213.4363.2980.6220.43212880019.9875 D0.5213.4363.2980.6220.43212880019.98E0.5210.9160.8790.3050.2121288009.818/3.0B0.5210.9160.8790.3050.21212880014.16C0.5213.4363.2980.6220.43212880028.85D0.5213.4363.2980.6220.43212880028.85E0.5210.9160.8790.3050.21212880014.167/3.0B0.5210.9160.8790.3050.21212880018.2075 C0.5213.4363.2980.6220.43212880037.09D0.5213.4363.2980.6220.43212880037.09E0.5210.9160.8790.3050.21212880018.206/3.0B0.5210.9160.8790.3050.21212880021.94C0.5213.4363.2980.6220.43212880044.70D0.5213.4363.2980.6220.43212880044.70E0.5210.9160.8790.3050.21212880021.9475 5/3.0B0.5210.9160.8790.3050.21212880025.34C0.5213.4363.2980.6220.43212880051.65D0.5213.4363.2980.6220.43212880051.65E0.5210.9160.8790.3050.21212880025.344/3.6B0.9750.9160.4500.1840.16611780024.56C0.9753.4361.7620.4680.42311780062.59D0.9753.4361.7620.4680.42311780062.5975 E0.9750.9160.4500.1840.16611780024.563/3.6B0.9750.9160.4500.1840.16611780027.30C0.9753.4361.7620.4680.42311780069.58D0.9753.4361.7620.4680.42311780069.58E0.9750.9160.4500.1840.16611780027.302/3.6B0.9750.9160.4500.1840.16611780029.57C0.9753.4361.7620.4680.42311780075.3675 D0.9753.4361.7620.4680.42311780075.36E0.9750.9160.4500.1840.16611780029.571/3.6B0.9750.9160.4500.1840.17211900032.19C0.9753.4361.7620.4680.42311900079.16D0.9753.4361.7620.4680.42311900079.16E0.9750.9160.4500.1840.17211900032.19B0.9750.4580.4500.3930.36617960045.1475 -1/3.6C0.9751.7181.7620.6010.54317960069.04D0.9751.7181.7620.6010.54317960069.04E0.9750.4580.4500.3930.35517960045.14各柱剪力计算设第i层第j个柱的D值为Dij,该层柱总数为m,该层任意柱的剪力为:Vij=Vi×(Dij/∑Dij)各柱剪力计算结果见(表-4)确定柱的反弯点高度比y反弯点距柱下端距离为yh:y=y0+y1+y2+y3式中y0—标准反弯点高度系数,y1—考虑上下层梁刚度不同时反弯点高度比的修正值y2,y3—考虑上下层层高变化时反弯点高度比的修正值y0根据结构总层数m及该柱所在层n及K值查表。75 例如,计算10层柱反弯点高度系数y:由m=11,n=11,K=0.879,查表得,y0=0.34;上下层梁相对刚度无变化,y1=0;最上层柱y2=0;下层层高与本层层高之比α3=h9/h10=1,查表得,y3=0;B轴反弯点高度系数为:y=y0+y1+y2+y3=0.34+0+0+0=0.34其余各柱反弯点高度系数见(表-5)。计算柱端弯矩根据各柱分配到的剪力及反弯点位置yh计算第i层第j个柱的柱端弯矩。上端弯矩:Mtij=Vij.h.(1-y)下端弯矩:Mbij=Vij.y.h计算结果见(表-5)。风荷载作用下柱反弯点高度比及柱端弯矩表-5层/hi柱列轴号Kα1α2α3y0Y1Y2Y3YMtij(KN.m)Mbij(KN.m)B0.8791010.3400000.34010.225.2675 10/3.0C3.2981010.4500000.45017.3614.20D3.2981010.4500000.45017.3614.20E0.8791010.3400000.34010.225.269/3.0B0.8791110.4000000.40017.6611.77C3.2981110.4650000.46532.0727.87D3.2981110.4650000.46532.0727.87E0.8791110.4000000.40017.6611.7775 8/3.0B0.8791110.4400000.44023.7918.69C3.2981110.5000000.50043.2843.28D3.2981110.5000000.50043.2843.28E0.8791110.4400000.44023.7918.697/3.0B0.8791110.4500000.45030.0324.57C3.2981110.5000000.50055.6455.64D3.2981110.5000000.50055.6455.6475 E0.8791110.4500000.45030.0324.576/3.0B0.8791110.4500000.45036.2029.62C3.2981110.5000000.50067.0567.05D3.2981110.5000000.50067.0567.05E0.8791110.4500000.45036.2029.625/3.0B0.879111.200.4500000.45041.8134.21C3.298111.200.5000000.50077.4877.4875 D3.298111.200.5000000.50077.4877.48E0.879111.200.4500000.45041.8134.214/3.6B0.45010.8310.4500000.45048.6339.79C1.76210.8310.5000000.500112.66112.66D1.76210.8310.5000000.500112.66112.66E0.45010.8310.4500000.45048.6339.793/3.6B0.4501110.5000000.50049.1449.1475 C1.7621110.5000000.500125.24125.24D1.7621110.5000000.500125.24125.24E0.4501110.5000000.50049.1449.142/3.6B0.4501110.5000000.50053.2353.23C1.7621110.5000000.500135.65135.65D1.7621110.5000000.500135.65135.65E0.4501110.5000000.50052.2353.2375 1/3.6B0.4501110.5000000.50057.9457.94C1.7621110.5000000.500142.49142.49D1.7621110.5000000.500142.49142.49E0.4501110.5000000.50057.9457.94-1/3.6B0.4501100.6500000.65056.88105.63C1.7621100.5500000.550111.84136.70D1.7621100.5500000.550111.84136.7075 E0.4501100.6500000.65056.88105.63计算梁端弯矩由柱端弯矩,并根据节点平衡原理计算梁端弯矩。边跨外边缘处的梁端弯矩Mbi=Mtij+Mbi+1,j中间支座处的梁端弯矩Mlbi=(Mtij+Mbi+1,j)(ilb/ilb+irb)Mrbi=(Mtij+Mbi+1,j)(irb/ilb+irb)框架在风荷载作用下的弯矩见(图-2)。75 计算梁支座剪力及柱轴力根据力平衡原理,由梁端弯矩和作用在梁上的竖向荷载可求出梁支座剪力;柱轴力可由计算截面之上的梁端剪力之和求得。框架在风荷载作用下的梁端剪力及柱轴力见(图-3)。梁柱弯曲产生的侧移因为H<50m,H/B<4,所以只考虑梁柱弯曲变形产生的侧移。第i层结构的层间变形为Δui,由公式Δun=Vn/ΣD可得。Δu10=31.36/128800=2.43×10-4m,Δu9=51.58/128800=4.63×10-4m,Δu8=86.01/128800=6.68×10-4m,Δu7=110.58/128800=8.59×10-4m,Δu6=133.28/128800=10.35×10-4m,75 Δu5=153.98/128800=11.95×10-4m,Δu4=174.30/117800=14.80×10-4m,Δu3=193.76/117800=16.45×10-4m,Δu2=209.86/117800=17.81×10-4m,Δu1=222.69/119000=18.71×10-4m,Δu-1=228.36/179600=12.71×10-4m,则顶点总侧移为:u=ΣΔuI=125.11×10-4m=12.511×10-3m顶点相对位移为:u/H=12.511×10-3/34.08=1/2724<1/550满足要求;最大层间相对位移为:Δu/H=1.871×10-3/3.6=1/1924<1/450满足要求。75 五.在竖向荷载作用下结构内力计算由平面图可以看出,本工程结构及荷载分布比较均匀,可以选取典型平面框架进行计算,横向框架可以仅取1、3、5、7、11轴框架,纵向框架需选取A、B、C、D、E轴框架进行计算,这里仅给出11轴框架的内力计算过程,纵向框架的计算方法与横向框架的计算方法相同,这里不再给出。各层框架梁上荷载计算屋面梁边跨均布荷载(雪荷与活荷不同时考虑):(7.125×1.2+1.5×1.4)×3.9+0.3×0.6×25×1.2=41.535+5.4=46.94KN/m,屋面梁中间跨均布荷载:0.3×0.6×25×1.2=5.4KN/m,屋面梁中间跨均布荷载:75 (7.125×1.2+1.5×1.4)×2.4=25.56KN/m,4~9层顶框架梁上荷载:梁自重--0.3×0.6×25×1.2=5.4KN/m2,板荷载--4.2×1.2+2×1.4=7.84KN/m2,200厚陶粒砼砌块墙2.4m高--2.4×2.4×1.2=6.912KN/m2,板上所砌隔墙转换为线荷载为:2.4×(2.1+2.4)×2.8/6.6=4.58KN/m,两边跨梁上均布荷载:5.4+7.84×3.9+4.58+6.912=60.75KN/m,中间跨梁上均布荷载:0.3×0.6×25×1.2=5.4KN/m,中间跨梁上三角形荷载(板传来):7.84×2.4=18.82KN/m,地下室至三层顶框架梁上荷载:梁自重--0.3×0.6×25×1.2=5.4KN/m2,板荷载--4.2×1.2+2×1.4=7.84KN/m2,200厚陶粒砼砌块墙3.0m高--2.4×3.0×1.2=8.64KN/m2,两边跨梁上均布荷载:5.4+7.84×3.9+8.64=44.62KN/m,中间跨框架梁上荷载与4~9层顶框架梁上荷载相同。竖向荷载作用下框架计算简图见(图-4)。75 内力计算多层多跨框架在竖向荷载作用下的内力近似按分层法计算。除底层以外,上层各柱线刚度均乘以0.9进行修正,这些柱的传递系数均取-1/3,底层柱的传递系数均取-1/2。竖向荷载引起的各层框架梁固端弯矩见(表-6)。弯矩分配系数计算公式为αj=ij/Σij。各节点弯矩分配系数计算结果见(表-7)。内力分层计算结果见(图-5)~(图-8)。竖向荷载作用下框架梁固端弯矩值表-675 层数BC跨CD跨DE跨左支座右支座左支座右支座左支座右支座10-170.39170.39-10.2610.26-170.39170.399-220.52220.52-8.248.24-220.52220.528-220.52220.52-8.248.24-220.52220.527-220.52220.52-8.248.24-220.52220.526-220.52220.52-8.248.24-220.52220.525-220.52220.52-8.248.24-220.52220.524-160.40220.52-8.248.24-220.52160.403-161.97161.97-8.248.24-161.97161.972-161.97161.97-8.248.24-161.97161.97175 -161.97161.97-8.248.24-161.97161.97-1-161.97161.97-8.248.24-161.97161.97各杆节点弯矩分配系数表-7层数B轴C轴D轴E轴下柱上柱梁下柱上柱梁左梁右下柱上柱梁左梁右下柱上柱梁100.53200.4680.23300.2050.5620.23300.5620.2050.53200.46890.3470.3470.3060.1890.1890.1640.4580.1890.1890.4580.1640.3470.3470.30680.3470.3470.3060.1890.1890.1640.4580.1890.1890.4580.1640.3470.3470.30670.3470.3470.3060.1890.1890.1640.4580.1890.1890.4580.1640.3470.3470.306675 0.3470.3470.3060.1890.1890.1640.4580.1890.1890.4580.1640.3470.3470.30650.3470.3470.3060.1890.1890.1640.4580.1890.1890.4580.1640.3470.3470.30640.4990.2670.2340.3030.1620.1430.3920.3030.1620.3920.1430.4990.2670.23430.4050.4050.1900.2660.2660.1250.3430.2660.2660.3430.1250.4050.4050.19020.4050.4050.1900.2660.2660.1250.3430.2660.2660.3430.1250.4050.4050.19075 10.4050.4050.1900.2660.2660.1250.3430.2660.2660.3430.1250.4050.4050.190-10.4050.4050.1900.2660.2660.1250.3430.2660.2660.3430.1250.4050.4050.19075 竖向荷载作用下框架弯矩图见(图-9)。竖向荷载作用下柱轴力及梁剪力图见(图-10)。75 一层顶的梁内力组合值及C轴柱内力组合值见(表-8)和(表-9)。75 11轴框架一层顶梁内力组合表-875 部位组号内力竖向荷载作用下风荷载作用下组合内力BC跨左支座1MmaxV139.76×0.8=111.81145.27114.82×1.4=160.7527.67×1.4=38.74272.56184.012MminV111.81145.27-106.75-38.74-48.94106.53跨中1Mmax96.64×1.2=115.97(114.82-67.8)×1.4/2=32.91148.88右支座1MmaxV152.86×0.8=122.29149.2367.8×1.4=94.9227.67×1.4=38.74217.21187.972MminV122.29149.23-94.92-38.7427.37110.4975 CD跨左支座1MmaxV44.27×0.8=35.4217.77186.53×1.4=261.14155.44×1.4=276.62296.56294.392MminV35.4217.77-261.14-276.62-225.72-258.85跨中1Mmax36.68×1.2=44.02044.02右支座1MmaxV43.65×0.8=34.9217.77186.53×1.4=261.14155.44×1.4=276.62296.06314.392MminV34.9217.77-261.14-276.62-226.22-258.85DE跨左支座1MmaxV152.86×0.8=122.29149.2367.8×1.4=94.9227.67×1.4=38.74217.21187.9775 2MminV122.29149.23-94.92-38.7427.37110.49跨中1Mmax95.90×1.2=115.08(114.82-67.80)×1.4/2=32.91147.99右支座1MmaxV141.24×0.8=112.99145.49114.82×1.4=160.7527.67×1.4=38.74273.74184.232MminV112.99145.49-160.75-38.74-47.76106.7511轴框架C轴柱部分截面内力组合表-9楼层部位组号内力竖向荷载作用下风荷载作用下组合内力柱上端1|M|max54.30114.84×1.4=156.58210.8875 地下室顶N6244.81-869.74×1.4=-1217.265027.552M54.30-114.84×1.4=-156.58-102.28Nmax6244.81869.74×1.4=1217.267462.07柱下端1|M|max27.20136.70×1.4=191.38218.58N6244.81-869.74×1.4=-1217.265027.552M27.20-136.70×1.4=-191.38-163.18Nmax6244.81869.74×1.4=1217.267462.0710层顶柱上端1|M|max66.7317.66×1.4=24.3091.03N658.81-8.36×1.4=-11.70647.112M66.73-17.66×1.4=-24.3042.4375 Nmax658.818.36×1.4=11.70670.51柱下端1|M|max84.8114.20×1.4=19.88104.69N658.81-8.36×1.4=-11.70647.112M84.81-14.20×1.4=-19.8864.93Nmax658.818.36×1.4=11.70670.51梁截面设计以地下室顶BC跨左支座截面为例。该截面负弯矩设计值为M=272.56KN.m,剪力设计值为V=184.01KN。正截面承载力计算求梁截面受压区高度:x=h0-(h02-2M/fcmb)1/2=565-(5652-2×272.56×106/12.5/300)1/2=135mm本工程建于6°抗震设防地区,可以不进行地震作用计算,根据规范规定,取无地震作用组合的情况,采用x≤ξbh0=0.544×75 565=307.36mm,满足要求。梁抗弯钢筋截面面积As计算:As=fcmbx/fy=13.5×300×135/310=1764mm2纵向受拉钢筋最小配筋百分率ρ=0.25%,最小配筋量为300×600×0.25%=4504mm2,为配筋选用4Φ25。斜截面承载力计算截面校核:25fcbh0=0.25×12.5×300×565=529688N=529.69KN>V=184.01KN截面满足要求。斜截面的受剪承载力按下式计算:Vcs≤0.07fcbh0+1.5fyv(Asv/s)h0Asv/s=(Vcs-0.07fcbh0)/1.5fyvh0=(184.01×103-0.07×12.5×300×565)/1.5×210×565=35697.5/177975=0.201取双肢φ8@250Asv/s=101/250=0.404>0.201箍筋的配箍率ρsv=Asv/bs,尚不应小于0.02fc/fyv。02fc/fyv)b=(0.02×12.5/210)×300=0.357,取双肢φ8@250Asv/s=101/250=0.404>0.357。根据规范中有关梁箍筋的构造要求及(表-10)的规定,梁端箍筋加密区长度取750mm,在加密区中箍筋最大间距取纵向钢筋直径的8倍,梁高的1/4或150mm三者中的最小值。实际取箍筋间距150mm。75 一层顶框架梁其余各截面配筋计算结果见(表-10)11轴框架一层顶梁配筋计算表表-9跨号BC跨CD跨DE跨位置左支座跨中右支座左支座跨中右支座左支座跨中右支座M(KN.m)-272.56148.68-217.21-296.56-44.02-296.56-217.21147.99-273.74X135751141642116411475135As(mm2)176498014892143274214314899801764选筋4Φ254Φ204Φ255Φ252Φ205Φ254Φ254Φ204Φ25V(KN)184.01187.97294.39314.39187.97184.23φφφφφ8@20φφφφ75 箍筋配置8@1508@2008@1508@10008@1008@1508@2008@150柱截面设计C轴地下室柱内力设计值:M=218.58KN.m,N=5027.55KN。柱计算长度l0=1.0H=3.6m,e0=M/N=218.58/5027.55=0.043m,ea=0.12(0.3h0-e0)=0.12(0.3×0.565-0.043)=0.015m,ei=e0+ea=0.043+0.015=0.058m,柱长细比l0/h=3.6/0.6=6<8,取η=1。e=ηei+h/2-as=1×0.058+0.3-0.025=0.333m。按对称配筋矩形截面计算:判别大小偏心受压:Nb=fcmbξbh0=19.5×600×0.544×565=359611N<5027.55KN因为Nb0.8%,柱端部箍筋加密区长度取600,箍筋最小体积配箍率取0.8%。柱箍筋取双向4肢φ10@200,满足陪箍百分率。该柱几个代表性截面处配筋计算结果见(表-11)。配筋计算得负值时为构造配筋。11轴框架C轴柱部分截面配筋计算表表-11截面位置弯矩(KN.m)轴力(KN)柱截面(mm2)砼级别e(m)ηAs(mm2)实配纵筋实配箍筋地下室上端210.885027.55600×600C400.3321-102012Φ204φ10@200102.287462.07600×600C400.3081259712Φ204φ10@20075 地下室下端218.585027.55600×600C400.3331-102012Φ204φ10@200163.187462.07600×600C400.3151292412Φ204φ10@20010层上端91.03647.11500×500C300.4161-4998Φ203φ10@20042.43670.51500×500C300.3471-6528Φ203φ10@20010层下端104.69647.11500×500C300.4371-2318Φ203φ10@20075 64.93670.51500×500C300.3771-5288Φ203φ10@200楼板配筋设计楼盖结构布置以三层楼板为例,其结构布置见(图-11),板厚如前所述选用120mm,水泥砂浆面层20厚,混合砂浆天棚抹灰15厚,楼面活荷载标准值为2.0KN/m2,混凝土采用C20(fcm=11N/mm2),钢筋为I级钢(fy=210N/mm2)。荷载计算20厚水泥砂浆面层0.02×20=0.40KN/m2,120厚楼板自重0.12×25=3.00KN/m2,75 15厚混合砂浆天棚抹灰15厚0.015×17=0.26KN/m2,恒荷标准值3.66KN/m2,恒荷设计值g=3.66×1.2=4.4KN/m2,活荷设计值q=2.00×1.4=2.8KN/m2,合计p=g+q=7.2KN/m2。内力计算(按塑性理论)B-1:ly/lx=8.1/3.9=2.1<3属于双向板B-2:ly/lx=6.6/3.9=1.7<3属于双向板B-3:ly/lx=3.9/3.3=1.2<3属于双向板B-4:ly/lx=5.4/3.9=1.4<3属于双向板B-5:ly/lx=7.8/3.3=2.4<3属于双向板B-6:ly/lx=7.8/2.4=3.3>3属于单向板(1)B-1(角区格)计算跨度:lx=l0=3.9-0.05-0.125=3.725m,ly=l0=8.1-0.05-0.15=7.90m,n=ly/lx=7.90/3.725=2.12,取α=1/n2=0.22,取β=2,Mx=(ly-lx/4)mx=(7.9-3.725/4)mx=6.97mx,My=(3/4)αlxmx=(3/4)×0.22×3.725mx=0.61mx,M’x=βlymx=2×7.9mx=15.8mx,M’’x=0,M’y=βαlxmx=2×0.22×3.725mx=1.64mx,M’’y=0,代入公式:75 2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×6.97mx+2×0.61mx+15.8mx+1.64mx=(3×7.9-3.725)7.2×3.7252/12故得:mx=5.1KN.m/m,my=αmx=0.22×5.1=1.12KN.m/m,m’x=βmx=2×5.1=10.2KN.m/m,m’’x=0,m’y=βmy=2×1.12=2.24KN.m/m,m’’y=0。(2)B-1(边区格)lx=l0=3.9-0.15-0.125=3.625m,ly=l0=8.1-0.05-0.15=7.90m,n=ly/lx=7.90/3.625=2.18,取α=1/n2=0.21,取β=2,Mx=(ly-lx/4)mx=(7.9-3.625/4)mx=6.99mx,My=(3/4)αlxmx=(3/4)×0.21×3.625mx=0.57mx,M’x=βlymx=2×7.9mx=15.8mx,M’’x=10.2×7.8=79.56,M’y=βαlxmx=2×0.21×3.625mx=1.52mx,M’’y=0,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×6.99mx+2×0.57mx+15.8mx+79.56+1.52mx=(3×7.9-3.625)7.2×3.6252/12故得:75 mx=2.5KN.m/m,my=αmx=0.21×2.5=0.53KN.m/m,m’x=βmx=2×2.5=5.0KN.m/m,m’’x=10.2,m’y=βmy=2×0.53=1.06KN.m/m,m’’y=0。(3)B-2(边区格)lx=l0=3.9-0.15-0.125=3.625m,ly=l0=6.6-0.05-0.15=6.40m,n=ly/lx=6.40/3.625=1.77,取α=1/n2=0.32,取β=2,Mx=(ly-lx/4)mx=(6.4-3.625/4)mx=5.49mx,My=(3/4)αlxmx=(3/4)×0.32×3.625mx=0.87mx,M’x=βlymx=2×6.4mx=12.8mx=M’’x,M’y=βαlxmx=2×0.32×3.625mx=2.32mx,M’’y=0,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×5.49mx+2×0.87mx+2×12.8mx+2.32mx=(3×6.4-3.625)7.2×3.6252/12故得:mx=3.0KN.m/m,my=αmx=0.32×3.0=0.96KN.m/m,m’x=βmx=2×3.0=6.0KN.m/m=m’’x,m’y=βmy=2×0.96=1.92KN.m/m,m’’y=0。75 (4)B-3(边区格)lx=l0=3.9-0.05-0.125=3.725m,ly=l0=3.3-0.125-0.15=3.025m,n=ly/lx=3.025/3.725=0.812,取α=1/n2=1.52,取β=2,Mx=(ly-lx/4)mx=(3.025-3.725/4)mx=2.1mx,My=(3/4)αlxmx=(3/4)×1.52×3.725mx=4.25mx,M’x=M’’x=0,M’y=βαlxmx=2×1.52×3.725mx=11.32mx=M’’y,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×2.1mx+2×4.25mx+2×11.32mx=(3×3.025-3.725)7.2×3.7252/12故得:mx=1.26KN.m/m,my=αmx=1.52×1.26=1.92KN.m/m,m’x=m’’x=0,m’y=βmy=2×1.92=3.84KN.m/m=m’’y。(5)B-4(边区格)lx=l0=3.9-0.15-0.125=3.625m,ly=l0=5.4-0.125-0.15=5.125m,n=ly/lx=5.125/3.625=1.41,75 取α=1/n2=0.5,取β=2,Mx=(ly-lx/4)mx=(5.125-3.625/4)mx=4.22mx,My=(3/4)αlxmx=(3/4)×0.5×3.625mx=1.36mx,M’x=βlymx=2×5.125mx=10.25mx=M’’x,M’y=βαlxmx=2×0.5×3.625mx=3.625mx,M’’y=0,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×4.22mx+2×1.36mx+2×10.25mx+3.625mx=(3×5.125-3.625)7.2×3.6252/12故得:mx=2.63KN.m/m,my=αmx=0.5×2.63=1.31KN.m/m,m’x=2×2.63=5.26KN.m/m=m’’x,m’y=βmy=2×1.31=2.62KN.m/m,m’’y=0。(6)B-5(边区格)lx=l0=7.8-0.3=7.5m,ly=l0=3.3-0.125-0.15=3.025m,n=ly/lx=3.025/7.5=0.4,取α=1/n2=6.15,取β=2,Mx=(ly-lx/4)mx=(3.025-7.5/4)mx=1.15mx,My=(3/4)αlxmx=(3/4)×6.15×7.5mx=34.6mx,M’x=βlymx=2×3.025mx=6.05mx=M’’x,75 M’y=βαlxmx=2×6.15×7.5mx=92.25mx,M’’y=0,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×1.15mx+2×34.6mx+2×6.05mx+92.25mx=(3×3.025-7.5)7.2×7.52/12故得:mx=0.3KN.m/m,my=αmx=6.15×0.3=1.86KN.m/m,m’x=2×0.3=0.6KN.m/m=m’’x,m’y=βmy=2×1.96=3.72KN.m/m,m’’y=0。(7)B-6(单向板)lx=l0=7.8-0.3=7.5m,ly=l0=3.3-0.125-0.15=3.025m,mx=m’x=0,my=m’y=ql2/11=7.2×2.12/16=1.98KN.m/m,配筋计算各区格板跨中及支座弯矩既已求得,取截面有效高度hox=100mm,hoy=90mm,可近似按As=M/(0.95hofy)计算钢筋截面面积,计算结果见(表-12)三层顶楼板配筋计算表表-1275 截面Mmax(KN.m)h0(mm)As(mm2)配筋实配跨中lx方向A-C轴之间6.99100350φ8@130387C-D轴之间01000φ6@200141B-31.2610063φ6@200141D-E轴之间6.99100350φ8@130387Ly方向1-2,14-15轴之间1.9890110φ6@2001412-3,13-14轴之间1.9890110φ6@2001413-6,10-13轴之间1.9890110φ6@2001416-7,9-10轴之间1.9890110φ6@2001417-9轴之间1.9890110φ6@20014175 支座lx方向1,15轴上A-C轴之间01000φ6@2001412,14轴上A-C轴之间10.2100511φ10@1505235,6,10,11,3-13轴上A-C轴之间6.0100501φ8@1503351,2,14,15轴上D-2/D轴之间01000φ8@2002513,13轴上D-E轴之间01000φ8@2002514,12轴上D-E轴之间6.0100301φ8@150335Ly方向A,B,E轴上0900φ8@200251C,D轴上1.929096φ8@2002512/D轴上7-9轴之间0900φ8@20025175 楼梯配筋设计本工程采用现浇板式楼梯,砼强度等级为C20,钢筋直径d≥14mm时采用II级钢,d≤12mm时采用I级钢。楼梯活荷载为2.5KN/m2。楼梯结构布置见(图-12)。斜板两端与平台梁和楼梯梁整结,平台板一端与平台梁整结,另外三端与框架梁整结,平台梁两端与框架梁整结。斜板TB-1设计取1m宽板带作为计算单元。确定斜板厚度t斜板的水平投影净长为:l1n=3300mm,75 斜板的斜向净长为:l’1n=l1n/cosα=3300/(300/(1502+3002)1/2)=3300/0.894=3691mm,斜板的厚度:t1=(1/25~1/30)l’1n=(1/25~1/30)3691=147~123mm,取t1=120mm。荷载计算见(表-13)楼梯斜板荷载计算表-13荷载种类荷载标准值(KN/m)荷载分项系数设计荷载(KN/m)恒荷载栏杆自重0.21.20.24锯齿形斜板自重γ1(d/2+t1/cosα)=25(0.15/2+0.12/0.894)=5.231.26.2830厚水磨石面层γ1c1(e+d)/e=25×0.03(0.15+0.3)/0.3=1.131.21.36板底20厚纸筋灰γ3c2/cosα=16×0.02/0.894=0.361.20.4375 小计g6.928.31活荷载q2.51.43.5总计p9.2411.81计算简图如(图-13)所示,计算跨度取斜板水平投影净长l1n=3300mm。内力计算斜板的内力,一般只需计算跨中最大弯矩即可。考虑到斜板两端均与梁整结,对板有约束作用,所以跨中最大弯矩取:M=Pl21n/10=11.81×3.32/10=12.86KN.m,75 配筋计算h0=t1-20=120-20=100mm。αs=M/fcmbh02=12.86×106/(11×1000×1002)=0.117γs=0.5(1+(1-2αs)1/2)=0.5(1+(1-2×0.117)1/2)=0.938As=M/fyγsh0=12.86×106/(210×0.938×100)=653mm2。选用:受力钢筋--φ10@120,As=654mm2,分布钢筋—φ6@300,(即每一踏步下放一根)平台板PB-1设计平台板计算简图取1m宽作为计算单元平台板近似地按短跨方向的简支板计算,计算简图见(图-14)。计算跨度:由于平台板两端均与梁整结,所以计算跨度取净跨:l2n=1300mm,平台板厚度取取t2=90mm。荷载计算见(表-14)楼梯平台板荷载计算表-14荷载种类荷载标准值(KN/m)荷载分项系数设计荷载(KN/m)75 恒载平台板自重25×0.09×1=2.251.26.2830厚水磨石面层25×0.03×1=0.751.21.36板底20厚纸筋灰16×0.02×1=0.321.20.43小计g3.323.98活荷载q2.51.43.5总计p5.827.48内力计算考虑到平台板两端梁的嵌固作用,中最大弯矩取:M=Pl21n/10=7.48×1.32/10=1.26KN.m,配筋计算h0=t1-20=90-20=70mm。αs=M/fcmbh02=1.26×106/(11×1000×702)=0.023γs=0.5(1+(1-2αs)1/2)=0.5(1+(1-2×0.023)1/2)=0.988As=M/fyγsh0=1.26×106/(210×0.988×100)=87mm2。选用:受力钢筋—φ6@200,As=141mm2,75 分布钢筋—φ6@250,(即每一踏步下放一根)平台板PB-2设计平台板计算简图取1m宽作为计算单元平台板近似地按两邻边嵌固、两邻边简支的双向板计算,计算跨度:lx3n=2550mm,ly3n=3200mm,平台板厚度取取t3=100mm。荷载计算见(表-14)。内力计算n=ly/lx=3.20/2.55=1.255,取α=1/n2=0.64,取β=2,Mx=(ly-lx/4)mx=(3.2-2.55/4)mx=2.5625mx,My=(3/4)αlxmx=(3/4)×0.64×2.55mx=1.224mx,M’x=βlymx=2×3.2mx=6.4mx,M’’x=0,M’y=βαlxmx=2×0.64×2.55mx=3.264mx,M’’y=0,代入公式:2Mx+2My+M’x+M’’x+M’y+M’’y=(3ly-lx)Plx2/122×2.5625mx+2×1.224mx+6.4mx+3.264mx=(3×3.2-2.55)7.2×2.552/12故得:mx=1.7KN.m/m,75 my=αmx=0.64×1.7=1.1KN.m/m,m’x=βmx=2×1.7=3.4KN.m/m,m’’x=0,m’y=βmy=2×1.1=2.2KN.m/m,m’’y=0。配筋计算h0x=100-20=80mm,h0y=100-30=70mm。跨中:αxs=M/fcmbh02=1.7×106/(11×1000×802)=0.024γxs=0.5(1+(1-2αs)1/2)=0.5(1+(1-2×0.024)1/2)=0.988Axs=M/fyγsh0=1.7×106/(210×0.988×80)=102mm2;αys=1.1×106/(11×1000×702)=0.020γys=0.990Ays=1.1×106/(210×0.990×70)=76mm2。支座:αxs=3.4×106/(11×1000×802)=0.048γxs=0.975Axs=3.4×106/(210×0.975×80)=208mm2;αys=2.2×106/(11×1000×702)=0.041γys=0.980Ays=2.2×106/(210×0.980×70)=153mm2。选用钢筋:跨中:受力钢筋—φ6@200,As=141mm2,分布钢筋—φ6@200,As=141mm2,75 支座:受力钢筋—φ8@200,As=251mm2,分布钢筋—φ6@150,As=189mm2。平台梁TL-1设计平台梁计算简图平台梁两端搁置在框架梁(或构造柱)上,所以计算跨度取l=l4n=3300-100=3200mm,平台梁计算简图见(图-15)平台梁截面尺寸为:b=250mm,h=350mm。荷载计算荷载计算见(表-15)平台梁荷载计算表表-15荷载种类荷载标准值(KN/m)荷载分项系数设计荷载(KN/m)恒载由斜板传来恒载6.92×l1n/2=6.92×3.3/2=11.421.213.775 由平台板传来恒载3.32×lx3n/2=3.32×2.55/2=4.2331.25.08平台梁自重25×0.09×1×0.35=2.51.23.0平台梁上30厚水磨石面层25×0.03×1×0.2=0.151.20.18平台梁底和侧面20厚纸筋灰16×0.02×1[0.25+2(0.35-0.12)]=0.261.20.31小计g18.56322.27活荷载q2.5×1×(3.3/2+2.55/2+0.25)=7.941.411.12总计p26.50333.39内力计算平台梁跨中截面最大弯矩:M=pl4n2/8=33.39×3.22/8=42.74KN.m,平台梁支座截面最大剪力:75 V=pl4n/2=33.39×3.2/2=53.42KN截面设计正截面承载力计算h0=h-35=350-35=315mm,αs=33.39×106/(11×250×3152)=0.122γys=0.935Ays=33.39×106/(310×0.935×315)=365mm2。考虑到平台梁两边受力不均,有扭矩存在,纵向受力钢筋酌量增大,故选用3Φ16,As=603mm2。斜截面承载力计算V/fcbh0=53.42×103/(10×250×315)=0.068<0.07,需要配置腹筋,选用φ6@200双肢箍,则Vcs=0.07fcbh0+1.5fyvh0(nAsv1/s)=0.07×10×250×315+1.5×210×315(2×28.3/200)=55125+28081=83206N≈83.21KN。Vcs>V,满足抗剪要求。75 基础部分高层建筑基础所占的工程量大、造价高、消耗的材料多、对建筑物施工工期影响很大。一般9~16层的高层建筑,基础部分的工期占总工期的1/3左右,造价也占总造价的1/3左右。因此,基础设计对高层建筑的经济技术指标有较大影响。分析地质资料、选择合理基础形式本工程场地地基土主要由第四纪冲、洪积物和基岩组成,由上而下分布为:①粉土,软塑-可塑,承载力低;②粉质粘土,软塑-可塑,含淤泥质土,承载力低;③细砂,饱和、稍密,承载力较低;④粉土,软塑-可塑,含淤泥,承载力较低;⑤中粗砂,稍密-中密,承载力较高;⑥粉土,可塑,承载力低;⑦碎石,中密-密实,由粘性土填充,承载力很高;⑧强风化片麻岩,承载力很高;⑨中风化片麻岩,承载力很高。场地地下水类型为潜水,水位在自然地面以下0.5~0.7m,无侵蚀性。该场地第①、③、④层土在地震烈度为7度时具有液化特性。75 根据上述地质资料描述可知,该地基土在沉积过程中分布不均,每层土的物理-力学性能指标有较大差异,容易产生不均匀沉降。因此,需要在结构上采取必要的加强措施,以及在基础选型上选用比较合理的基础型式。从地质剖面上来看,本工程场地上部土层较软,承载力较低,而且中部有软弱下卧层,故不宜作为天然地基,而下部有可作为持力层的坚实土层,故宜采用桩基础。若采用筏型基础或交叉梁式基础,因本工程柱网尺寸较大,筏板及基础梁断面会很大,从经济角度考虑,不宜采用此种基础形式。若采用箱型基础,虽然其整体性较好,能够减少差异沉降量,但本工程土层压缩性较高,其基础总沉降量不易满足。采用桩基础就可以解决上述问题的困扰,而且,一旦发生罕遇地震时,建筑物不至于因为地基土液化而倒塌或损坏,因为桩基础可以跨过软弱土层将上部荷载传给下部较好土层。综上所述。本工程基础形式最终定为桩基础。确定基础埋深基础的埋深必须满足地基承载力和稳定性的要求,防止倾覆和滑移。高层建筑的基础埋深,对于桩基础不宜小于建筑物高度的1/15,桩的长度不计在内。本工程因为有地下室(层高3.6m),故取基础承台顶面标高为-3.8m。选择桩型根据本工程场地地基土层状况,查桩基规范(JGJ94-94)“成桩工艺选择参考表”,本工程适合采用振动沉管灌注桩。该桩型可以穿越地基上部软弱土层,使桩尖达到下部碎石层。本工程拟采用直径为400mm的振拔桩,桩长定为12m75 ,持力层为碎石层,桩身砼强度等级为C20。单桩承载力的计算和桩数的确定计算单桩承载力根据地质资料给出的土的性质,查桩基规范可得桩的极限侧阻力标准值qsik,和极限端阻力标准值qpk。如下:qs1k=40Kpa,qs2k=35Kpa,qs3k=33Kpa,qs4k=43Kpa,qs5k=58Kpa,qs6k=48Kpa,qs7k=110Kpa,qpk=8500Kpa。根据土的物理指标与承载力参数之间的经验关系,确定单桩竖向极限承载力标准值时,按下式计算:Quk=Qsk+Qpk=uΣqsikli+qpkAp因桩径为400,故u=πd=3.14×0.4=1.256m,Ap=πr2=3.14×0.22=0.1256m2。Quk=1.256(35×2.4+33×2.5+43×3.5+58×0.9+48×1.8+110×0.5)+8500×0.1256=1.256×510.6+1067.6=641.3+1067.6=1708.9单桩竖向极限承载力设计值为:R=Quk/γsp=1708.9/1.70=1005KN桩数的确定和布置按试算法,偏心受压时所需的桩数n,可按中心受压计算并乘以一个增大系数μ=1.1~1.2。即:n=μ(F+G)/R中柱75 F=7462K,NM=102KN.m,G=1.2×25×3.2×6.8×1.2=783KN.则n1=1.1×(7462×2+783)/1005=17.2取n1=18,设桩中心距为S=3.5d=3.5×400=1400mm。根据布桩原则,采用(图-16)的布桩形式。边柱F=5378K,NM=149.4KN.m,G=1.2×20×3.6×1.2×4.0=415KN.则n2=1.1×(5378+415)/1005=6.34取n2=6,设桩中心距为S=3.5d=3.5×400=1400mm。根据布桩原则,采用(图-17)的布桩形式。75 单桩承载力验算按下式计算:Q=(F+G)/n≤R,Qmax=(F+G)/n±Mxmax/Σxi2±Mymax/Σyi2。中柱对于中柱,因为两柱距离较近,承台已连成一个整体,而承台刚度又比较大,故柱根弯矩完全由承台来承担,对桩基础不会产生偏心荷载,可不验算Qmax,只需验算Q≤R。Q=(7462×2+783)/18=8730,满足要求。基础结构设计桩身设计查桩基规范可知,当桩顶轴向压力满足下式要求时,桩身可按构造配筋。γ0≤fcA,本工程γ0=1,Nmax=993KN,fC=10N/mm2,A=0.1256m2。fcA=10×125600=1256000N=1256KN>γ0N=993KN。故本工程可以按构造配筋。本工程建筑桩基安全等级为二级,根据规范要求,桩身需配置4~8根φ10~φ12的桩顶与承台连接钢筋,锚入承台至少30倍主筋直径,且伸入桩身长度不小于5d,对于沉管灌注桩,配筋长度不应小于承台下软弱土层层底深度。本工程桩身配5根φ12主筋,箍筋为φ6@100/200。主筋通长配置。承台设计中柱下承台CT-1承台采用C30砼,设承台高为h=1200mm,则承台有效高度为h0=1200-50=1150mm。冲切强度验算按下式验算:Vmax≤Vc=0.6ftbmh0,75 Vc=0.6×1.5×5600×1150=5796000N=5796KN,Vmax=873×3=2619KN