臨時(shí)便橋受力計(jì)算書1、 便橋概述便橋橋跨布置為10x5m,全長共50m。橋?qū)?.5m,凈寬4.0m。便橋位于施工橋南側(cè)5m處，通航凈空高度不小于1.30m?；A(chǔ)：便橋基礎(chǔ)采用15?17m長杉木，平均直徑不小于20cm，每個(gè)橋墩24根。杉木樁用斜撐進(jìn)行加固和294X200H鋼連接(代替原來的大、小枕木連接)，形成群樁基礎(chǔ)。主梁：縱向主梁采用294x200x8x12H型鋼，間距50cm。橋面系：縱梁上鋪設(shè)16a型工字鋼作橫向分配梁，分配梁間距為40cm，單根長度為4.5m，16a型工字鋼頂鋪設(shè)8mm花紋鋼板作為橋面板，橋面板與分配梁需焊接固定。2、 計(jì)算依據(jù)《公路橋涵設(shè)計(jì)通用規(guī)范》(JTGD60-2004)《公路橋涵地基與基礎(chǔ)設(shè)計(jì)規(guī)范》(JTGD63-2007)《公路橋涵鋼結(jié)構(gòu)及木結(jié)構(gòu)設(shè)計(jì)規(guī)范》(JTJ025-86)《建筑樁基礎(chǔ)技術(shù)規(guī)范》(JGJ94-2008)3、 容許應(yīng)力容許應(yīng)力按《公路橋涵鋼結(jié)構(gòu)及木結(jié)構(gòu)設(shè)計(jì)規(guī)范》規(guī)定：A3鋼：彎曲應(yīng)力［訝=145 剪應(yīng)力［T］=85MPa4、 受力計(jì)算4.1、模型計(jì)算采用midas/civil2011對臨時(shí)鋼便橋上部結(jié)構(gòu)進(jìn)行建模計(jì)算。橋面鋼板采用板單元，其他縱梁、橫梁采用梁單元建模。荷載：最大荷載為載重60t的水泥粉罐車，自重15t，總重按80t計(jì)算，車輛沿便橋中心線行駛。計(jì)算結(jié)果荷載組合值：自重乘以1.2荷載組合系數(shù)，活載乘以1.4荷載組合系數(shù)。便橋上部結(jié)構(gòu)模型圖（局部模型）4.1、橋面鋼板受力計(jì)算2.912076+0012.68285e+0012.912076+0012.68285e+0012.45363e+0012.22440e+0011.9951Se+0011.76596e+0011.53674e+0011.30751e+0011.07829e+001S.49069e+0006.19847e+0003.'90624e+0006.066066+0015.18713e+0014.30S19e+0013.42925e+0012.E5031e+0011.67138e+0017.'324306+0000.00000e+000-9.65437e+000-1.84437e+001-2.72331e+001-3.60225e+001鋼面板組合應(yīng)力圖由計(jì)算結(jié)果知：最大應(yīng)力：°=29.lMPaV□=i45MPa3.2、16a工字鋼橫向分配梁受力計(jì)算1jtfld*1.'SO'je^e+OOl1.56243e+001121523e+0018.68022e+000520S17e+0001.73613e+000O.OOOOOe+OOO-5.20797e+00i：i-S,6S002e+00i：i-1.21521e+001-1.56241e+001-l.'jO'jeSe+OOl16a工字鋼橫向分配梁剪應(yīng)力圖由計(jì)算結(jié)果知：最大組合應(yīng)力：°=60.6MPaV□=i45MPa最大剪應(yīng)力：，=19MPaV[]=85MPa4.3、294X200H型鋼縱梁受力計(jì)算5.22635S+001431943e+0013.41250e+0012.50558e+0011S9865e+0016.91726e+000O.OOOOOe+OOO-1.12213e+001-2.i5.22635S+001431943e+0013.41250e+0012.50558e+0011S9865e+0016.91726e+000O.OOOOOe+OOO-1.12213e+001-2.i：i2905e+001-2.'335386+001-3.84290e+00154.0E70Ee+0013.31506e+0012.57306e+00154.0E70Ee+0013.31506e+0012.57306e+0011.83107e+001M-1.08908e+001H-0.00000e+000--3.94907e-i-000 1.13690e+001 1.87889e+001H--2.62089e+001■--3,362885+001-4.104S7e+001X-DIR=O.OOOE+OOONODE=1Y-DIR=O.OOOE+OOONODE=1Z-DIR=-2,210E+000NODE=86SCOMB.=2.247E+000NODE=511系敏=5.6E5E+002294X200H型鋼縱梁變位圖由計(jì)算結(jié)果知：最大組合應(yīng)力：0=52.2MPa<L]=145MPa最大剪應(yīng)力：t=40.5MPa<口=85MPa最大撓度：f=2.2mm<[f]=亞皿=8.3mm600最，反力節(jié)點(diǎn)=9S8FZi1.5'972￡+002上部結(jié)構(gòu)反力圖（平面視角）最大支點(diǎn)反力：R=159.7kN木樁間距0.6m，按0.6m簡支梁計(jì)算最大正應(yīng)力圖宜LI L2 LWLZ 1切 1切最大剪應(yīng)力圖_」_」_」_」L_r---ElrI,最大變形圖最大正應(yīng)力：°=36MPaV[J=i88.5MPa最大最應(yīng)力:,=70.9MPaV口=110.5MPa最大撓度：/=0.156mmV[/]=600=imm6003.5、木樁基礎(chǔ)計(jì)算木樁基礎(chǔ)按照群樁基礎(chǔ)計(jì)算，由反力計(jì)算結(jié)果知單個(gè)橋墩最大受力：R=705.7kN根據(jù)《建筑樁基礎(chǔ)技術(shù)規(guī)范》（JGJ94-2008）樁承載力計(jì)算公式Q=Q+Q=u￡ql+人qAskpk sikippkP式中：u—樁身周長，u=0.2ml—土分層厚度（m）i入p一樁端土塞效應(yīng)系數(shù)，取0.8A—樁端面積（0.0314m2）pqsik—與對應(yīng)的各土層與樁側(cè)的摩阻力標(biāo)準(zhǔn)值（kPa）qk—極限端阻力標(biāo)準(zhǔn)值（kPa）,根據(jù)規(guī)范取210kPa安全系數(shù)取2.0木樁入淤泥層10m,淤泥層樁周摩阻力標(biāo)準(zhǔn)值為10kPaoQ=24x(3.14x0.2x10x10+0.8x0.0314x210)=1632kN>R=2x705.7=1411.4kN滿足要求