满堂支架计算书.doc

附件1 现浇箱梁满堂支架受力计算书一、现浇箱梁满堂支架布置及搭设要求采用WDJ碗扣式多功能脚手杆搭设，使用与立杆配套的横杆及立杆可调底座、立杆可调托撑。立杆顶设二层方木，立杆顶托上纵向设1515cm方木；纵向方木上设1010cm的横向方木，其中在墩顶端横梁和跨中横隔梁下间距不大于0.25m（净间距0.15m）、在跨中其他部位间距不大于0.3m（净间距0.2m）。模板宜用厚1.5cm的优质竹胶合板，横板边角宜用4cm厚木板进行加强，防止转角漏浆或出现波浪形，影响外观。具体布置见下图：支架横断面图、支架搭设平面图、支架搭设纵断面图 支架横断面图0支架搭设平面图支架搭设纵断面图25主桥和引桥立杆的纵、横向间距及横杆步距等搭设要求如下：（1）30m+45m+30m顶推现浇箱梁支架立杆采用横桥向间距纵桥向间距步距为60cm60cm120cm、60cm90cm120cm和90cm90cm120cm三种布置形式的支架结构体系，其中：横桥向中心8.4m范围间距60cm，两侧翼缘板3.6m范围间距90cm。纵桥向墩旁两侧各4.0m范围内的支架间距60cm；除墩旁两侧各4m之外的其余范围内的支架间距90cm，跨中横隔板下1.5m范围内的支架顺桥向间距加密至60cm。（2）2*27.45m、4*29.439m、3*28.667m、4*28.485m现浇箱梁支架立杆采用横桥向间距纵桥向间距步距为60cm60cm120cm、60cm90cm120cm和90cm90cm120cm三种布置形式的支架结构体系，其中：横桥向中心8.4m范围间距60cm，两侧翼缘板3.6m范围间距90cm。纵桥向墩旁两侧各4.0m范围内的支架间距60cm；除墩旁两侧各4m之外的其余范围内的支架间距90cm。二、现浇箱梁支架验算本计算书分别以顶推梁30m+45m+30m等截面预应力混凝土箱形连续梁（单箱双室）和4*28.485m等截面预应力混凝土箱形连续梁（单箱双室）为例，对荷载进行计算及对其支架体系进行检算。1、荷载分析根据本桥现浇箱梁的结构特点，在施工过程中将涉及到以下荷载形式： F1 箱梁自重荷载，新浇混凝土密度取2700kg/m(含钢筋重)。 F2 施工人员、施工材料和机具荷载，按均布荷载计算，取F2 = 2.5 kN/ F3 振捣混凝土产生的荷载，取F3 = 2.0 kN/。 F4 箱梁内模、底模、内模支撑及外模支撑荷载，按均布荷载计算，取F4 = 2.0 kN/。 F5 方木 方木单位重取600Kg/m F5取0.465kN/ F6 浇筑混凝土时产生的冲击荷载，取F6=2.0kN/ F7 风荷载，取F7=0.70.60.840.45=0.16kN/（风荷载体型系数取0.6，风压高度变化系数取0.84，郑州基本风压取0.45，取自建筑结构荷载规范）2、截面选择根据现浇箱梁结构特点(箱梁结构图见附图)，顶推连续梁取11截面（墩顶及横梁，60cm60cm120cm布置受力最大位置）、55截面（60cm60cm120cm布置受力位置）、现浇连续梁取截面（墩顶及横梁，60cm60cm120cm布置受力最大位置）、截面（60cm90cm120cm布置受力位置）四个代表截面进行支架体系检算。3、荷载计算（1）11截面（墩顶及横隔梁）处支架受力最大的部位为中腹板下方，故取此部分进行受力计算= 2.827 = 75.6kN/偏安全考虑，箱梁荷载取1.2倍计算F1 = 1.275.6 = 90.72kN/ 底模强度检算箱梁底模采用高强度竹胶板，板厚t = 15mm。竹胶板方木背肋间距为15cm。 q = (F1+F2+F3+F4+F6+F7)0.15= (90.72+2.5+2.0+2.0+2.0+0.16)0.15 = 14.92kN/m模板力学性能：弹性模量：E = 0.1 105 Mpa截面惯性矩：I = bh3/12 = 151.53/12 = 4.218cm4截面抵抗矩：W = bh2/6 = 151.52/6 = 5.625cm跨中最大弯矩：M = ql2/8 = (14.920.152)/8 = 0.042kNm弯拉应力：= M/W = (0.042103)/(5.62510-6) = 7.47MPa 【】= 11MPa挠度：f=(5ql4)/384EI=(514.920.154)/(3840.11054.21810-8)=0.233mm L/400 = 0.375mm 综上,底模强度满足要求。 横向木枋强度检算横向方木为1010cm方木，跨径为0.6m，中对中间距为0.25m.横向方木力学性能：截面抵抗矩：W = bh2/6 = (0.10.12)/6 = 1.6710-4m截面惯性矩：I = bh3/12 = (0.10.13)/12 = 8.3310-6m4q=(F1+F2+F3+F4+F6+F7)0.25=(90.72+2.5+2.0+2.0+2.0+0.16)0.25 =24.86kN/m跨中最大弯矩： M = ql2/8 = (24.860.62)/8 = 1.12kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量：E = 11103MPa抗弯强度检算= M/W = (1.12103)/(1.6710-4) = 6.67MPa 【】= 14.5MPa抗剪强度检算Q = ql = 24.860.6= 14.92 KNA = 0.10.1=0.01=Q/2A = 14.9210-3/（20.01） = 0.75MPa 【】= 2.3MPa刚度验算 f = 5ql4/384EI = (524.860.64)/(384111038.3310-6)= 0.458mm L/400 = 1.5mm综上，横向木枋强度满足要求。 纵向木枋强度检算纵向木枋为1515cm.跨径为0.6m.间距为0.6m.截面惯性矩:I = bh3/12 = 0.150.153/12 = 4.2210-5m4截面抵抗矩:W = bh2/6 = 0.150.152/6 = 5.62510-4m先按荷载为集中荷载进行检算0.6m长纵梁上承担的每根横梁重量为:0.10.10.66 = 0.036kNq=0.036/0.6=0.06kN/m作用在横梁上的集中荷载为P = q横0.6+0.081 = 24.860.6+0.036 = 14.95kN跨中最大弯矩:M =P(a2b+ab2+l3/8)/l2=14.950.6(0.0520.55+0.5520.05+0.63/8)/0.62=1.12kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量E = 11103MPa横梁弯拉应力:= M/W = (1.12103)/( 5.62510-4) = 1.98MPa 【】= 14.5MPa.抗剪强度检算Q = P= 14.95 KNA = 0.150.15=0.0225=3Q/2A = (314.9510-3)/（20.0225）= 0.997MPa 【】= 2.3MPa 横梁挠度f =(a(3l2-4a2)*2+l3)P/48EI =(0.05(30.62-40.052)2+0.63)14.95/（48111064.2210-5） =0.216mm L/400 = 1.5mm再按荷载为均布荷载进行检算作用于纵梁上的均布荷载为:q纵 = (F1+F2+F3+F4+F6+F7)0.6+0.06 = 59.73kN/m跨中最大弯矩为:M = ql2/8 = 59.730.62/8 = 2.69kNm横梁弯拉应力= M/W = 2.69/(5.62510-4) = 4.78MPa 【】= 14.5MPa 抗剪强度检算 Q = ql = 59.730.6= 35.838KNA = 0.15*0.15=0.0225=Q/2A = 35.83810-3/（20.0225） = 0.796MPa 【】= 2.3MPa横梁挠度检算f = 5ql4/384EI = (559.730.64)/(384111064.2210-5)= 0.215mm L/400 = 1.5mm综上,纵梁强度满足要求. 碗扣架强度稳定性检算碗扣架布置间距为6060cm,所以每根钢管承受上部6060cm面积的重量,由箱梁的构造可知,腹板下方的碗扣架受力最大.正中立杆进行验算，F = 1.2272.80.60.6+ (F2+F3+F4+F5+F6+F7)0.60.6 = 35.97kN根据建筑施工碗扣式钢管脚手架安全技术规范5.1.7查得碗扣架规格为483.5mm,l = 120cm,回转半径为1.58cm，根据建筑施工碗扣式钢管脚手架安全技术规范5.1.6查得Q235A级钢材抗压设计值f=205N/mm2 = l / i = 120/1.58= 76 参照建筑施工碗扣式钢管脚手架安全技术规范查附录E得0.744。S = 3.14(48/2)2-(48-2.8*2)2/4)= 397.6mm2(偏安全考虑，壁厚取2.8mm)f = 35.97103/（0.744397.6）= 121.6N/ mm2 【f】= 205N/mm2综上,碗扣架抗压强度和稳定性满足要求. 地基承载力检算地基处理将杂填土挖除,然后换填60cm厚三七灰土,上面浇筑20cm厚C25砼.碗扣架下面用底托支撑,示意图如下顶托底的承载力为35.97/(0.150.15) = 1598.7kPa三七灰土和砼扩散角均按30o计20.45tan30o = 0.921598.70.152/(0.15+0.92)2 = 31.4kPa 180kPa（2）55截面处支架受力最大的部位为中腹板下方，故取此部分进行受力计算= 2.827 = 75.6kN/偏安全考虑，箱梁荷载取1.2倍计算F1 = 1.275.6 = 90.72kN/ 底模强度检算箱梁底模采用高强度竹胶板，板厚t = 15mm。竹胶板方木背肋间距为15cm。 q = (F1+F2+F3+F4+F6+F7)0.15= (90.72+2.5+2.0+2.0+2.0+0.16)0.15 = 14.92kN/m模板力学性能：弹性模量：E = 0.1 105 Mpa截面惯性矩：I = bh3/12 = 151.53/12 = 4.218cm4截面抵抗矩：W = bh2/6 = 151.52/6 = 5.625cm跨中最大弯矩：M = ql2/8 = (14.920.152)/8 = 0.042kNm弯拉应力：= M/W = (0.042103)/(5.62510-6) = 7.47MPa 【】= 11MPa挠度：f=(5ql4)/384EI=(514.920.154)/(3840.11054.21810-8)=0.233mm L/400 = 0.375mm 综上,底模强度满足要求。 横向木枋强度检算横向方木为1010cm方木，跨径为0.6m，中对中间距为0.3m.横向方木力学性能：截面抵抗矩：W = bh2/6 = (0.10.12)/6 = 1.6710-4m截面惯性矩：I = bh3/12 = (0.10.13)/12 = 8.3310-6m4 q = (F1+F2+F3+F4+F6+F7)0.3 = (90.72+2.5+2.0+2.0+2.0+0.16)0.3 = 29.84kN/m跨中最大弯矩： M = ql2/8 = (29.840.62)/8 = 1.34kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量：E = 11103MPa抗弯强度检算= M/W = (1.34103)/(1.6710-4) = 8.0MPa 【】= 14.5MPa抗剪强度检算Q = ql = 29.840.6= 17.9 KNA = 0.10.1=0.01=Q/2A = 17.910-3/（20.01） = 0.895MPa 【】= 2.3MPa刚度验算 f = 5ql4/384EI = (529.840.64)/(384111038.3310-6)= 0.55mm L/400 = 1.5mm综上，横向木枋强度满足要求。 纵向木枋强度检算纵向木枋为1515cm.跨径为0.9m.间距为0.6m.截面惯性矩:I = bh3/12 = 0.150.153/12 = 4.2210-5m4截面抵抗矩:W = bh2/6 = 0.150.152/6 = 5.62510-4m先按荷载为集中荷载进行检算0.6m长纵梁上承担的每根横梁重量为:0.10.10.66 = 0.036kNq=0.036/0.6=0.06kN/m作用在横梁上的集中荷载为P = q横0.6+0.036 = 29.840.6+0.036 = 17.94kN跨中最大弯矩:M =P(a2b+ab2+l3/8)/l2=17.940.6(0.1520.75+0.7520.15+0.93/8)/0.92=2.56kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量E = 11103MPa横梁弯拉应力:= M/W = (2.56103)/( 5.62510-4) = 4.55MPa 【】= 14.5MPa.抗剪强度检算Q = P= 17.94 KNA = 0.15*0.15=0.0225=3Q/2A = (317.9410-3)/（20.0225）= 1.2MPa 【】= 2.3MPa横梁挠度f =(a(3l2-4a2)*2+l3)P/48EI =(0.15(30.92-40.152)2+0.93)17.94/ （48111064.2210-5） =1.15mm L/400 =2.25mm再按荷载为均布荷载进行检算作用于纵梁上的均布荷载为:q纵 = (F1+F2+F3+F4+F6+F7)0.6+0.06 = 58.74kN/m跨中最大弯矩为:M = ql2/8 = 58.740.92/8 = 6.05kNm横梁弯拉应力= M/W = 6.05/(5.62510-4) = 10.9MPa 【】= 14.5MPa 抗剪强度检算 Q = ql = 58.740.9= 52.866KNA = 0.15*0.15=0.0225=Q/2A = 52.86610-3/（20.0225） = 1.17MPa 【】= 2.3MPa横梁挠度检算f = 5ql4/384EI = (558.8660.94)/(384111064.2210-5)= 1.08mm L/400 = 2.25mm综上,纵梁强度满足要求. 碗扣架强度稳定性检算碗扣架布置间距为6090cm,所以每根钢管承受上部6090cm面积的重量,由箱梁的构造可知,腹板下方的碗扣架受力最大.正中立杆进行验算，F =1.2【27（2.80.6-0.71）】0.9+(F2+F3+F4+F5+F6+F7)0.60.9= 32.25kN根据建筑施工碗扣式钢管脚手架安全技术规范5.1.7查得碗扣架规格为483.5mm,l = 120cm,回转半径为1.58cm，根据建筑施工扣件式钢管脚手架安全技术规范5.1.6查得Q235A级钢材抗压设计值f=205N/mm2 = l / i = 120/1.58= 76 参照建筑施工碗扣式钢管脚手架安全技术规范查附录E得0.744。S = 3.14(48/2)2-(48-2.8*2)2/4)= 397.6mm2(偏安全考虑，壁厚取2.8mm)f = 32.25103/（0.744397.6）= 109.02N/ mm2 【f】= 205N/mm2综上,碗扣架抗压强度和稳定性满足要求. 地基承载力检算地基处理将杂填土挖除,然后换填60cm厚三七灰土,上面浇筑20cm厚C25砼.碗扣架下面用底托支撑,示意图如下顶托底的承载力为32.25/(0.150.15) = 1433kPa三七灰土和砼扩散角均按30o计20.45tan30o = 0.9214330.152/(0.15+0.92)2 = 28.17kPa 180kPa（3）截面支架受力最大的部位为中腹板下方，故取此部分进行受力计算= 227 = 54kN/偏安全考虑，箱梁荷载取1.2倍计算F1 = 1.254 = 64.8kN/ 底模强度检算箱梁底模采用高强度竹胶板，板厚t = 12mm。竹胶板方木背肋间距为15cm。q = (F1+F2+F3+F4+F6+F7)0.15= (64.8+2.5+2.0+2.0+2.0+0.16)0.15 = 11.0kN/m模板力学性能： 弹性模量：E = 0.1 105 Mpa 截面惯性矩：I = bh3/12 = 151.23/12 = 2.16cm4 截面抵抗矩：W = bh2/6 = 151.22/6 = 3.6cm 跨中最大弯矩：M = ql2/8 = (11.00.122)/8 = 0.02kNm 弯拉应力：= M/W = (0.02103)/(3.610-6) = 5.56MPa 【】= 11MPa 挠度：f = (5ql4)/384EI = (511.00.154)/(3840.11052.1610-8) = 0.33mm L/400 = 0.375mm 综上,底模强度满足要求. 横向木枋强度检算横向方木为1010cm方木，跨径为0.6m，中对中间距为0.25m.横向方木力学性能： 截面抵抗矩：W = bh2/6 = (0.10.12)/6 = 1.6710-4m 截面惯性矩：I = bh3/12 = (0.10.13)/12 = 8.3310-6m4 q = (F1+F2+F3+F4+F6+F7)0.25 = (64.8+2.5+2.0+2.0+2.0+0.16)0.25 = 18.4kN/m跨中最大弯矩： M = ql2/8 = (18.40.62)/8 = 0.83kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量：E = 11103MPa抗弯强度检算= M/W = (0.83103)/(1.6710-4) = 5.0MPa 【】= 14.5MPa抗剪强度检算Q = ql = 18.40.6= 11.0 KNA = 0.10.1=0.01=Q/2A = 11.010-3/（20.01） = 0.55MPa 【】= 2.3MPa刚度验算 f = 5ql4/384EI = (518.40.64)/(384111038.3310-6)= 0.34mm L/400 = 1.5mm综上，横向木枋强度满足要求。 纵向木枋强度检算纵向木枋为1515cm.跨径为0.6m.间距为0.6m.截面惯性矩:I = bh3/12 = 0.150.153/12 = 4.2210-5m4截面抵抗矩:W = bh2/6 = 0.150.152/6 = 5.62510-4m先按荷载为集中荷载进行检算0.6m长纵梁上承担的每根横梁重量为:0.10.10.66 = 0.036kNq=0.036/0.6=0.06kN/m作用在横梁上的集中荷载为P = q横0.6+0.081 = 18.40.6+0.036 = 11.1kN跨中最大弯矩:M =P(a2b+ab2+l3/8)/l2=11.10.6(0.0520.55+0.5520.05+0.63/8)/0.62=0.8kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量E = 11103MPa横梁弯拉应力:= M/W = (0.8103)/( 5.62510-4) = 1.4MPa 【】= 14.5MPa.抗剪强度检算Q = P= 11.1 KNA = 0.150.15=0.0225=3Q/2A = (311.110-3)/（20.0225）= 0.74MPa 【】= 2.3MPa横梁挠度f =(a(3l2-4a2)*2+l3)P/48EI =(0.05(30.62-40.052)2+0.63)11.1/（48111064.2210-5） =0.16mm L/400 = 1.5mm再按荷载为均布荷载进行检算作用于纵梁上的均布荷载为:q纵 = (F1+F2+F3+F4+F6+F7)0.6+0.06 = 44.2kN/m跨中最大弯矩为:M = ql2/8 = 44.20.62/8 = 2.0kNm横梁弯拉应力= M/W = 2.0/(5.62510-4) = 3.6MPa 【】= 14.5MPa 抗剪强度检算 Q = ql = 44.20.6= 26.6KNA = 0.150.15=0.0225=Q/2A = 26.610-3/（20.0225） =0.59MPa 【】= 2.3MPa横梁挠度检算f = 5ql4/384EI = (544.20.64)/(384111064.2210-5)= 0.16mm L/400 = 1.5mm综上,纵梁强度满足要求. 碗扣架强度稳定性检算碗扣架布置间距为6060cm,所以每根钢管承受上部6060cm面积的重量,由箱梁的构造可知,中腹板下方的碗扣架受力最大.正中立杆进行验算，F = 1.22720.60.6+ (F2+F3+F4+F5+F6+F7)0.60.6 = 26.6kN根据建筑施工碗扣式钢管脚手架安全技术规范5.1.7查得碗扣架规格为483.5mm,l = 120cm,回转半径为1.58cm，根据建筑施工扣件式钢管脚手架安全技术规范5.1.6查得Q235A级钢材抗压设计值f=205N/mm2 = l / i = 120/1.58= 76 参照建筑施工碗扣式钢管脚手架安全技术规范查附录E得0.744。S = 3.14(48/2)2-(48-2.8*2)2/4)= 397.6mm2(偏安全考虑，壁厚取2.8mm)f = 26.6103/（0.744397.6）= 89.9N/ mm2 【f】= 205N/mm2综上,碗扣架抗压强度和稳定性满足要求. 地基承载力检算地基处理将杂填土挖除,然后换填60cm厚三七灰土,上面浇筑20cm厚C25砼.碗扣架下面用底托支撑,示意图如下顶托底的承载力为26.6/(0.150.15) = 1182.2kPa三七灰土和砼扩散角均按30o计20.8tan30o = 0.921182.20.152/(0.15+0.92)2 = 23.2kPa 180kPa（4）截面支架受力最大的部位为中腹板下方，故取此部分进行受力计算= 227 = 54kN/偏安全考虑，箱梁荷载取1.2倍计算F1 = 1.254 = 64.8kN/ 底模强度检算箱梁底模采用高强度竹胶板，板厚t = 12mm。竹胶板方木背肋间距为15cm。 q = (F1+F2+F3+F4+F6+F7)0.15= (64.8+2.5+2.0+2.0+2.0+0.16)0.15 =10.95kN/m模板力学性能： 弹性模量：E = 0.1 105 Mpa 截面惯性矩：I = bh3/12 = 151.23/12 = 2.16cm4 截面抵抗矩：W = bh2/6 = 151.22/6 = 3.6cm 跨中最大弯矩：M = ql2/8 = (10.950.122)/8 = 0.02kNm 弯拉应力：= M/W = (0.02103)/(3.610-6) = 5.6MPa 【】= 11MPa 挠度：f = 5ql4/384EI = (510.950.154)/(3840.11052.1610-8) = 0.03mm L/400 = 0.375mm 综上,底模强度满足要求.横向木枋强度检算横向方木为1010cm方木，跨径为0.6m，中对中间距为0.3m.横向方木力学性能： 截面抵抗矩：W = bh2/6 = (0.10.12)/6 = 1.6710-4m 截面惯性矩：I = bh3/12 = (0.10.13)/12 = 8.3310-6m4 q = (F1+F2+F3+F4+F6+F7)0.3 = (64.8+2.5+2.0+2.0+2.0+0.16)0.3 = 22.1kN/m跨中最大弯矩： M = ql2/8 = (22.10.62)/8 = 1.0kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量：E = 11103MPa抗弯强度检算= M/W = (1.0103)/(1.6710-4) = 6.0MPa 【】= 14.5MPa抗剪强度检算Q = ql = 22.10.6= 13.26 KNA = 0.10.1=0.01=Q/2A = 13.2610-3/（20.01） = 0.66MPa 【】= 2.3MPa刚度验算 f = 5ql4/384EI = (522.10.64)/(384111038.3310-6)= 0.4mm L/400 = 1.5mm综上，横向木枋强度满足要求。 纵向木枋强度检算纵向木枋为1515cm.跨径为0.9m.间距为0.6m.截面惯性矩:I = bh3/12 = 0.150.153/12 = 4.2210-5m4截面抵抗矩:W = bh2/6 = 0.150.152/6 = 5.62510-4m先按荷载为集中荷载进行检算0.6m长纵梁上承担的每根横梁重量为:0.10.10.66 = 0.036kNq=0.036/0.6=0.06kN/m作用在横梁上的集中荷载为P = q横0.6+0.081 = 22.10.6+0.036 = 13.3kN跨中最大弯矩:M =P(a2b+ab2+l3/8)/l2=13.30.6(0.1520.75+0.7520.15+0.93/8)/0.92=1.9kNm东北落叶松容许抗弯应力【】= 14.5MPa.弹性模量E = 11103MPa横梁弯拉应力:= M/W = (1.9103)/( 5.62510-4) = 3.4MPa 【】= 14.5MPa.抗剪强度检算Q = P= 13.3 KNA = 0.15*0.15=0.0225=3Q/2A = (313.310-3)/（20.0225）= 0.89MPa 【】= 2.3MPa横梁挠度f =(a(3l2-4a2)*2+l3)P/48EI =(0.15(30.92-40.152)2+0.93)13.3/（48111064.2210-5） =0.85mm L/400 = 2.25mm再按荷载为均布荷载进行检算作用于纵梁上的均布荷载为:q纵 = (F1+F2+F3+F4+F6+F7)0.6+0.06 = 44.2kN/m跨中最大弯矩为:M = ql2/8 = 44.20.92/8 = 4.5kNm 横梁弯拉应力= M/W = 4.5/(5.62510-4) = 8.0MPa 【】= 14.5MPa 抗剪强度检算 Q = ql = 44.20.9= 39.8KNA = 0.150.15=0.0225=Q/2A = 39.810-3/（20.0225） = 0.88MPa 【】= 2.3MPa横梁挠度检算f = 5ql4/384EI = (544.20.94)/(384111064.2210-5)= 1.03mm L/400 = 2.25mm综上,纵梁强度满足要求. 碗扣架强度稳定性检算碗扣架布置间距为6090cm,所以每根钢管承受上部6090cm面积的重量,由箱梁的构造可知,中腹板下方的碗扣架受力最大.正中立杆进行验算，F =1.2【27（20.6-0.47）】0.9+(F2+F3+F4+F5+F6+F7)0.60.9= 28.6kN根据建筑施工碗扣式钢管脚手架安全技术规范5.1.7查得碗扣架规格为483.5mm,l = 120cm,回转半径为1.58cm，根据建筑施工扣件式钢管脚手架安全技术规范5.1.6查得Q235A级钢材抗压设计值f=205N/mm2 = l / i = 120/1.58= 76 参照建筑施工碗扣式钢管脚手架安全技术规范查附录E得0.744。S = 3.14(48/2)2-(48-2.8*2)2/4)= 397.6mm2(偏安全考虑，壁厚取2.8mm)f = 28.6103/（0.744397.6）= 96.7N/ mm2 【f】= 205N/mm2综上,碗扣架抗压强度和稳定性满足要求. 地基承载力检算地基处理将杂填土挖除,然后换填60cm厚三七灰土,上面浇筑20cm厚C25砼.碗扣架下面用底托支撑,示意图如下顶托底的承载力为28.6/(0.150.15) = 1271kPa三七灰土和砼扩散角均按30o计20.8tan30o = 0.9212710.152/(0.15+0.92)2 = 24.98kPa 180kPa