宏博办公楼框架结构设计

第5章截面设计5.1框架梁正截面设计纵向受拉筋最小配筋率计算：①跨中，“规范”要求，ρmin（百分率）取0.2和45ft/fy中较大值，本框架采用C30混凝土和二级钢筋，ft＝1.43N/mm2，fy=300N/mm2，45ft/fy＝45×1.43÷300＝0.21，所以框架梁跨中受拉筋最小配筋率取0.21%；②支座处，“规范”要求，ρmin（百分率）取0.25和55ft/fy中较大值,55ft/fy＝55×1.43÷300＝0.26，所以框架梁支座处受拉筋最小配筋率取0.26%。在框架梁的正弯矩计算时，按T形截面考虑，T形截面的bf′为：边跨，bf′＝l0/3＝6000/3＝2000（mm），取为2000mm；中跨，bf′＝l0/3＝2400/3＝800（mm），取800mm。“规范”要求：①三、四级抗震等级，沿梁全长顶面和底面至少应各配置两根通长的纵向钢筋，钢筋直径不应小于12mm；②框架梁抗震要求b≤0.35；③框架梁梁端载面的底部和顶部纵向受力钢筋截面面积的比值，除按计算确定外，二、三抗震等级不应小于0.3；④边跨梁腹板高度因大于450，按要求应配置构造筋，故在梁腹板三分点处每侧配置两根12钢筋。⑤梁端混凝土受压区高度，要求二、三级抗震等级x≤0.35h0,且梁端纵向受拉钢筋的配筋率不应大于2.5%。框架梁正截面设计计算见表5-1。5.2框架梁斜截面设计1、截面限制条件验算。①hw/b≤4时，V≤0.25fcbh0；②考虑地震作用组合，当跨高比l0/h＞2.5时，应有V≤0.2fcbh0/γRE，经验算，满足上述要求。2、最小配箍率计算。沿梁全长配箍率ρsv≥0.26ft/fy′＝0.26×1.43÷210＝0.18%。3、构造要求。箍筋加密区长度取1.5h和500中较大值，故：边跨取1050，中跨取750；箍筋加密区最大箍筋间距取纵筋直径的8倍和梁高的1/4和150中的最小值，本框架取为100；所有箍筋均选为ф10。表5-1框架梁正截面设计计算表楼层构件名称截面位置弯矩值(kN·m)b(bf')(mm)h0(mm)(%)As,min(mm2)计算As(mm2)选配钢筋实配As(mm2)五层边跨梁A端-144.472505850.0670.0690.5500.26390.006562Ф22760跨中101.0423005850.0130.0130.5500.21316.797012Ф22760B端-124.552505850.0830.0870.5500.26394.437202Ф22760中跨梁B端69.86800585————————-121.242505850.0850.0890.5500.26398.887152Ф22760跨中-14.982505850.0360.0370.5500.21323.981682Ф22760四层边跨梁A端-235.552505850.0760.0790.5500.26403.357512Ф22760跨中107.323005850.0130.0130.5500.21327.607002Ф22760B端-204.022505850.0870.0910.5500.26407.856902Ф22760中跨梁B端198.688005850.0080.0080.5500.26410.10177——-239.572505850.0920.0970.5500.26412.367182Ф22760跨中-11.592505850.0360.0370.5500.21334.891202Ф22760三层边跨梁A端20.932300585————————-270.352505850.090.0940.5500.26419.177452Ф22760跨中110.1223005850.0130.0130.5500.21340.407012Ф22760B端-228.33250585————————-268.82505850.0910.0960.5500.26426.037352Ф22760中跨梁B端268.80800585————————-311.312505850.1050.1110.5500.26430.627492Ф22760跨中-10.002505850.0360.0370.5500.21349.671462Ф22760二层边跨梁A端56.602300585————————-306.752505850.0990.1040.5500.26437.567492Ф22760跨中107.4823005850.0130.0130.5500.21355.293592Ф22760B端15.712300585————————-271.122505850.0950.10.5500.26444.543642Ф22760中跨梁B端392.038005850.0150.0150.5500.26446.88234——-433.292505850.1160.1240.5500.26449.226082Ф22760跨中-9.678005850.0360.0370.5500.21364.731012Ф22760一层边跨梁A端100.292300585————————-340.292505850.110.1170.5500.26456.287552Ф22760跨中113.0723005850.0130.0130.5500.21370.441472Ф22760B端66.822300585————————-316.312505850.10.1060.5500.26463.387432Ф22760中跨梁B端525.128005850.0190.0190.5500.26465.76560——-577.282505850.1310.1410.5500.26468.157422Ф22760跨中16.198005850.0380.0390.5500.21380.05982Ф22760由框架梁内力组合表可以看出，在考虑γRE后，地震组合的剪力并不起控制作用，故斜截面设计按不考虑地震组合进行，但构造配筋应满足抗震要求，计算结果见表5-2。计算公式为:表5-2框架梁斜截面设计计算表楼层构件名称截面位置V(kN)b(mm)h0(mm)(%)计算(mm)加密区非加密区实配箍筋(%)实配箍筋(%)五层边跨梁A端115.202505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19B端109.562505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19中跨梁B端83.302505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19四层边跨梁A端166.802505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19B端167.732505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19中跨梁B端159.052505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19三层边跨梁A端175.052505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19B端167.882505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19中跨梁B端202.462505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19二层边跨梁A端186.482505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19B端187.422505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19中跨梁B端268.552505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19一层边跨梁A端197.782505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19B端-199.502505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.19中跨梁B端342.372505850.18＜0Φ8@100,双肢0.58Φ8@200,双肢0.195.3框架柱正截面设计纵向受力钢筋最小配筋率。根据“规范”要求，对于三级框架，框架柱中全部纵向钢筋的配筋百分率不应小于①角柱：0.9%；②其余柱0.7%；③每一侧的配筋百分率0.2%。箍筋的设置。因各柱的剪力均不大，经试算按构造配筋足够，故无需计算，仅按构造配筋即可；考虑抗震等级，选定所有箍筋直径均为10，柱端加密区箍筋间距为100，非加密区箍筋间距为200；加密区长度：①底层柱底从基础顶面往上1800，②底层柱顶从梁底往下750，③其余各柱的柱顶及柱底均为650，④梁柱相交部分应加密。框架柱计算长度。底层柱：l0＝1.0H＝1.0×4500＝4500（mm）其余各层柱：l0＝1.25H＝1.25×3600＝4500（mm）计算方法。框架柱正截面设计计算采用“规范”提供的公式。当对称配筋时，受压区高度，当时，为大偏心受压，当时，为小偏心受压。对于大偏心受压状态，当时，由公式可求得，其中当时，由公式求得，其中,对于小偏心受压状态，需重新计算，按下面公式计算：此处，对于C30混凝土，α1＝1.0，β1＝0.8。于是由可求得当计算所得或小于构造要求的最小配筋面积时，按构造要求选配钢筋，并考虑施工的方便性。计算过程及结果见表5-3。表5-3框架柱正截面设计计算表(单位M—kN·mN—kN)楼层构件名称截面位置内力值b(mm)h(mm)l0(mm)ei(mm)偏心类别ρmin(%)计算As=As′(mm2)选配钢筋实配As=As′(mm2)ρ(%)单侧全部单侧全部五层边柱柱顶6506504500242大偏心0.20.7112312B1830540.360.726506504500231大偏心0.20.7145612B1830540.360.726506504500215大偏心0.20.7125112B1830540.360.72柱底6506504500201大偏心0.20.7135412B1830540.360.726506504500223大偏心0.20.7155612B1830540.360.726506504500128大偏心0.20.7189012B1830540.360.72中柱柱顶6506504500282大偏心0.20.7177412B1830540.360.726506504500231大偏心0.20.7167512B1830540.360.726506504500124大偏心0.20.7201312B1830540.360.72柱底6506504500268大偏心0.20.7189012B1830540.360.726506504500240大偏心0.20.7195112B1830540.360.726506504500119大偏心0.20.7194312B1830540.360.72四层边柱柱顶6506504500244大偏心0.20.7186412B1830540.360.726506504500246大偏心0.20.7195212B1830540.360.726506504500164大偏心0.20.7205612B1830540.360.72柱底6506504500231大偏心0.20.7212012B1830540.360.726506504500231大偏心0.20.7212312B1830540.360.726506504500158大偏心0.20.7156212B1830540.360.72中柱柱顶6506504500229大偏心0.20.7109612B1830540.360.726506504500178大偏心0.20.7132012B1830540.360.72650650450091大偏心0.20.7109812B1830540.360.72柱底6506504500221大偏心0.20.7209312B1830540.360.72650650450099大偏心0.20.7246712B1830540.360.72650650450089大偏心0.20.7236512B1830540.360.72三层边柱柱顶6506504500198大偏心0.20.7214212B1830540.360.72650650450097大偏心0.20.7231212B1830540.360.726506504500129大偏心0.20.7265412B1830540.360.72柱底6506504500193大偏心0.20.7212612B1830540.360.726506504500189大偏心0.20.7235612B1830540.360.726506504500127大偏心0.20.7279812B1830540.360.72中柱柱顶6506504500197大偏心0.20.7285212B1830540.360.726506504500197大偏心0.20.7259112B1830540.360.72650650450067大偏心0.20.7269412B1830540.360.72柱底6506504500193大偏心0.20.7246512B1830540.360.726506504500196大偏心0.20.7213412B1830540.360.72650650450066大偏心0.20.7289012B1830540.360.72二层边柱柱顶6506504500168大偏心0.20.7247312B1830540.360.72650650450076大偏心0.20.7291512B1830540.360.726506504500111大偏心0.20.7296412B1830540.360.72柱底6506504500167大偏心0.20.7245612B1830540.360.72650650450081大偏心0.20.7291012B1830540.360.726506504500110大偏心0.20.7267012B1830540.360.72中柱柱顶6506504500175大偏心0.20.7293312B1830540.360.72650650450098大偏心0.20.7275012B1830540.360.72650650450057大偏心0.20.7264312B1830540.360.72柱底6506504500173大偏心0.20.7293412B1830540.360.72650650450069大偏心0.20.7301212B1830540.360.72650650450058大偏心0.20.7295412B1830540.360.72一层边柱柱顶6506504500156大偏心0.20.7289712B1830540.360.72650650450089大偏心0.20.7279812B1830540.360.72650650450088大偏心0.20.7264512B1830540.360.72柱底6506504500164大偏心0.20.7300612B1830540.360.72650650450091大偏心0.20.7303112B1830540.360.72650650450076大偏心0.20.7303012B1830540.360.72中柱柱顶6506504500166大偏心0.20.7300912B1830540.360.72650650450089大偏心0.20.7298012B1830540.360.72650650450042小偏心0.20.7275612B1830540.360.72柱底6506504500175大偏心0.20.7262712B1830540.360.726506504500189大偏心0.20.7286512B1830540.360.72650650450031小偏心0.20.7275612B1830540.360.72

总结随着经济的迅猛发展，人们综合素质的提高，人们对建筑的要求已不但是经久耐用，而且要求美观、舒适、保温及隔声等功能。这就对建筑行业提出了新的要求，从建筑的外形设计、结构设计及建筑材料等方面均提出了更高要求，同时为我国建筑行业的发展提供了新的契机。本次我的设计题目是“宏博教学楼框架结构设计”，该工程位于武汉市郊区，地震设防烈度为7度，本工程采用框架结构。总的设计思路：在建筑结构的两个主轴方向分别考虑水平地震作用，各方向的水平地震作用应全部由该方向抗侧力结构承担。采用框架结构计算的近似法求解内力，即：求竖向荷载作用下的内力按无侧移框架用弯距二次分配法，求水平地震作用下的内力按三角形分布用D值法。最后利用钢筋混凝土的相关原理进行构件配筋计算及校核。通过对框架结构的设计计算，全面的复习巩