鋼板樁支護(hù)計(jì)算書全套

鋼板樁支護(hù)計(jì)算書計(jì)算依據(jù)：1、《建筑基坑支護(hù)技術(shù)規(guī)程》JGJ120-20122、《建筑施工計(jì)算手冊(cè)》江正榮編著3、《實(shí)用土木工程手冊(cè)》第三版楊文淵編著4、《施工現(xiàn)場(chǎng)設(shè)施安全設(shè)計(jì)計(jì)算手冊(cè)》謝建民編著5、《土力學(xué)與地基基礎(chǔ)》6、《鋼板樁》JG/T196-2018一、參數(shù)信息1、基本參數(shù)支護(hù)樁材料鋼板樁支護(hù)樁嵌入土深度ld(m)7.5基坑開挖深度h(m)4.5基坑外側(cè)水位深度ha(m)1.5基坑內(nèi)側(cè)水位深度hp(m)1支護(hù)樁是否設(shè)置支撐是基坑形狀矩形基坑支撐工作面高度y(m)32、支撐高度位置參數(shù)支撐道數(shù)各道支撐距基坑頂部距離S(m)10.53、土層參數(shù)土層類型土厚度h(m)土重度γ(kN/m3)粘聚力c(kPa)內(nèi)摩擦角φ(°)飽和土重度γsat(kN/m3)水土分算填土2.618.421.913.324.288否淤泥質(zhì)二5.717.714.510.925.31否粘性土12.719.118.518.224.63否4、荷載參數(shù)類型荷載q(kpa)距支護(hù)邊緣的水平距離a(m)垂直基坑邊的分布寬度b(m)平行基坑邊的分布長(zhǎng)度l(m)作用深度d(m)矩形局部荷載201.54.544.805、計(jì)算系數(shù)結(jié)構(gòu)重要性系數(shù)γ01.1綜合分項(xiàng)系數(shù)γF1.25嵌固穩(wěn)定安全系數(shù)Ke1.2總體示意圖土壓力分布示意圖附加荷載布置圖二、根據(jù)實(shí)際嵌固深度計(jì)算支護(hù)樁穩(wěn)定性1、主動(dòng)土壓力計(jì)算1）主動(dòng)土壓力系數(shù)Ka1=tan2(45°-φ1/2）=tan2(45-13.3/2)=0.626；Ka2=tan2(45°-φ2/2）=tan2(45-13.3/2)=0.626；Ka3=tan2(45°-φ3/2）=tan2(45-10.9/2)=0.682；Ka4=tan2(45°-φ4/2）=tan2(45-18.2/2)=0.524；Ka5=tan2(45°-φ5/2）=tan2(45-18.2/2)=0.524；2）土壓力、地下水產(chǎn)生的水平荷載第1層土：0-1.5mH1'=[∑γ0h0]/γi=[0]/18.4=0mPak1上=γ1H1'Ka1-2c1Ka10.5=18.4×0×0.626-2×21.9×0.6260.5=-34.653kN/m2Pak1下=γ1(h1+H1')Ka1-2c1Ka10.5=18.4×(1.5+0)×0.626-2×21.9×0.6260.5=-17.377kN/m2第2層土：1.5-2.6mH2'=[∑γ1h1]/γsati=[27.6]/24.288=1.136mPak2上=γsat2H2'Ka2-2c2Ka20.5=24.288×1.136×0.626-2×21.9×0.6260.5=-17.377kN/m2Pak2下=γsat2(h2+H2')Ka2-2c2Ka20.5=24.288×(1.1+1.136)×0.626-2×21.9×0.6260.5=-0.654kN/m2第3層土：2.6-8.3mH3'=[∑γ2h2]/γsati=[54.317]/25.31=2.146mPak3上=γsat3H3'Ka3-2c3Ka30.5=25.31×2.146×0.682-2×14.5×0.6820.5=13.093kN/m2Pak3下=γsat3(h3+H3')Ka3-2c3Ka30.5=25.31×(5.7+2.146)×0.682-2×14.5×0.6820.5=111.476kN/m2第4層土：8.3-9mH4'=[∑γ3h3]/γsati=[198.584]/24.63=8.063mPak4上=γsat4H4'Ka4-2c4Ka40.5=24.63×8.063×0.524-2×18.5×0.5240.5=77.275kN/m2Pak4下=γsat4(h4+H4')Ka4-2c4Ka40.5=24.63×(0.7+8.063)×0.524-2×18.5×0.5240.5=86.309kN/m2第5層土：9-12mH5'=[∑γ4h4]/γsati=[215.825]/24.63=8.763mPak5上=γsat5H5'Ka5-2c5Ka50.5=24.63×8.763×0.524-2×18.5×0.5240.5=86.309kN/m2Pak5下=γsat5(h5+H5')Ka5-2c5Ka50.5=24.63×(3+8.763)×0.524-2×18.5×0.5240.5=125.027kN/m23）水平荷載臨界深度：Z0=2.6m第1層土Eak1=0kN；第2層土Eak2=0kN；第3層土Eak3=h3(Pak3上+Pak3下)ba/2=5.7×(13.093+111.476)×1/2=355.022kN；aa3=h3(2Pak3上+Pak3下)/(3Pak3上+3Pak3下)+∑h4=5.7×(2×13.093+111.476)/(3×13.093+3×111.476)+3.7=5.8m；第4層土Eak4=h4(Pak4上+Pak4下)ba/2=0.7×(77.275+86.309)×1/2=57.254kN；aa4=h4(2Pak4上+Pak4下)/(3Pak4上+3Pak4下)+∑h5=0.7×(2×77.275+86.309)/(3×77.275+3×86.309)+3=3.344m；第5層土Eak5=h5(Pak5上+Pak5下)ba/2=3×(86.309+125.027)×1/2=317.004kN；aa5=h5(2Pak5上+Pak5下)/(3Pak5上+3Pak5下)=3×(2×86.309+125.027)/(3×86.309+3×125.027)=1.408m；土壓力合力：Eak=ΣEaki=0+0+355.022+57.254+317.004=729.281kN；合力作用點(diǎn)：aa=Σ(aaiEaki)/Eak=(0×0+0×0+5.8×355.022+3.344×57.254+1.408×317.004)/729.281=3.698m；2、被動(dòng)土壓力計(jì)算1）被動(dòng)土壓力系數(shù)Kp1=tan2(45°+φ1/2）=tan2(45+10.9/2)=1.466；Kp2=tan2(45°+φ2/2）=tan2(45+10.9/2)=1.466；Kp3=tan2(45°+φ3/2）=tan2(45+18.2/2)=1.908；2）土壓力、地下水產(chǎn)生的水平荷載第1層土：4.5-5.5mH1'=[∑γ0h0]/γi=[0]/17.7=0mPpk1上=γ1H1'Kp1+2c1Kp10.5=17.7×0×1.466+2×14.5×1.4660.5=35.117kN/m2Ppk1下=γ1(h1+H1')Kp1+2c1Kp10.5=17.7×(1+0)×1.466+2×14.5×1.4660.5=61.072kN/m2第2層土：5.5-8.3mH2'=[∑γ1h1]/γsati=[17.7]/25.31=0.699mPpk2上=γsat2H2'Kp2+2c2Kp20.5=25.31×0.699×1.466+2×14.5×1.4660.5=61.072kN/m2Ppk2下=γsat2(h2+H2')Kp2+2c2Kp20.5=25.31×(2.8+0.699)×1.466+2×14.5×1.4660.5=164.992kN/m2第3層土：8.3-12mH3'=[∑γ2h2]/γsati=[88.568]/24.63=3.596mPpk3上=γsat3H3'Kp3+2c3Kp30.5=24.63×3.596×1.908+2×18.5×1.9080.5=220.136kN/m2Ppk3下=γsat3(h3+H3')Kp3+2c3Kp30.5=24.63×(3.7+3.596)×1.908+2×18.5×1.9080.5=394.05kN/m23）水平荷載第1層土Epk1=bah1(Ppk1上+Ppk1下)/2=1×1×(35.117+61.072)/2=48.095kN；ap1=h1(2Ppk1上+Ppk1下)/(3Ppk1上+3Ppk1下)+∑h2=1×(2×35.117+61.072)/(3×35.117+3×61.072)+6.5=6.955m；第2層土Epk2=bah2(Ppk2上+Ppk2下)/2=1×2.8×(61.072+164.992)/2=316.49kN；ap2=h2(2Ppk2上+Ppk2下)/(3Ppk2上+3Ppk2下)+∑h3=2.8×(2×61.072+164.992)/(3×61.072+3×164.992)+3.7=4.885m；第3層土Epk3=bah3(Ppk3上+Ppk3下)/2=1×3.7×(220.136+394.05)/2=1136.244kN；ap3=h3(2Ppk3上+Ppk3下)/(3Ppk3上+3Ppk3下)=3.7×(2×220.136+394.05)/(3×220.136+3×394.05)=1.675m；土壓力合力：Epk=ΣEpki=48.095+316.49+1136.244=1500.828kN；合力作用點(diǎn)：ap=Σ(apiEpki)/Epk=(6.955×48.095+4.885×316.49+1.675×1136.244)/1500.828=2.522m；3、嵌固穩(wěn)定性驗(yàn)算參考《建筑基坑支護(hù)技術(shù)規(guī)程》JGJ120-2012，第4.2.2條被動(dòng)土壓力合力到樁底的距離ap1=ap=2.522m主動(dòng)土壓力合力到樁底的距離aa1=aa=3.698m被動(dòng)土壓力合力到支撐位置的距離ap2=h+ld-ap-s1=4.5+7.5-2.522-0.5=8.978m主動(dòng)土壓力合力到支撐位置的距離aa2=h+ld-aa-s1=4.5+7.5-3.698-0.5=7.802mEpkap2/(Eakaa2)=1500.828×8.978/(729.281×7.802)=2.368≥Ke=1.2滿足要求！三、確定支護(hù)樁最小嵌固深度，并分析各工況下支護(hù)樁受力工況1：開挖至0.5+3=3.5m深度，支撐尚未施工，此處支護(hù)樁處于懸臂狀態(tài)開挖工況圖如下：工況1示意圖1、計(jì)算嵌固深度確定要使板樁保持穩(wěn)定，當(dāng)前開挖工況下嵌固深度需滿足主動(dòng)土壓力造成的彎矩、基坑內(nèi)側(cè)被動(dòng)土壓力造成的彎矩總和平衡，即ΣM=0;同時(shí)需滿足《建筑基坑支護(hù)技術(shù)規(guī)程》JGJ120-2012第4.2.7條，對(duì)懸臂式支護(hù)結(jié)構(gòu)，嵌固深度不小于0.8倍的開挖深度。根據(jù)以上條件，通過試算法得到，計(jì)算嵌固深度為t=1.04m。1.04m深度以下土壓力計(jì)算時(shí)不考慮?？紤]嵌固穩(wěn)定安全系數(shù)1.2后，并滿足規(guī)范最小嵌固深度要求，當(dāng)前開挖工況支護(hù)樁實(shí)際嵌固深度8.5m≥max(1.2×1.04，0.8×3.5)=2.8m當(dāng)前工況支護(hù)樁嵌固深度滿足要求！2、當(dāng)前工況下計(jì)算嵌固深度范圍內(nèi)的土壓力計(jì)算參考《規(guī)范》JGJ120-2012，計(jì)算支護(hù)樁結(jié)構(gòu)時(shí)，只考慮彎矩平衡點(diǎn)以上部分（即：計(jì)算錨固深度范圍內(nèi)）的土壓力，所以當(dāng)前工況下只顯示錨固深度為1.04m范圍的土壓力。1）主動(dòng)土壓力計(jì)算①主動(dòng)土壓力系數(shù)Ka1=tan2(45°-φ1/2）=tan2(45-13.3/2)=0.626；Ka2=tan2(45°-φ2/2）=tan2(45-13.3/2)=0.626；Ka3=tan2(45°-φ3/2）=tan2(45-10.9/2)=0.682；②土壓力、地下水產(chǎn)生的水平荷載第1層土：0-1.5mH1'=[∑γ0h0]/γi=[0]/18.4=0mPak1上=γ1H1'Ka1-2c1Ka10.5=18.4×0×0.626-2×21.9×0.6260.5=-34.653kN/m2Pak1下=γ1(h1+H1')Ka1-2c1Ka10.5=18.4×(1.5+0)×0.626-2×21.9×0.6260.5=-17.377kN/m2第2層土：1.5-2.6mH2'=[∑γ1h1]/γsati=[27.6]/24.288=1.136mPak2上=γsat2H2'Ka2-2c2Ka20.5=24.288×1.136×0.626-2×21.9×0.6260.5=-17.377kN/m2Pak2下=γsat2(h2+H2')Ka2-2c2Ka20.5=24.288×(1.1+1.136)×0.626-2×21.9×0.6260.5=-0.654kN/m2第3層土：2.6-4.54mH3'=[∑γ2h2]/γsati=[54.317]/25.31=2.146mPak3上=γsat3H3'Ka3-2c3Ka30.5=25.31×2.146×0.682-2×14.5×0.6820.5=13.093kN/m2Pak3下=γsat3(h3+H3')Ka3-2c3Ka30.5=25.31×(1.94+2.146)×0.682-2×14.5×0.6820.5=46.578kN/m22）被動(dòng)土壓力計(jì)算①被動(dòng)土壓力系數(shù)Kp1=tan2(45°+φ1/2）=tan2(45+10.9/2)=1.466；Kp2=tan2(45°+φ2/2）=tan2(45+10.9/2)=1.466；②土壓力、地下水產(chǎn)生的水平荷載第1層土：3.5-4.5mH1'=[∑γ0h0]/γi=[0]/17.7=0mPpk1上=γ1H1'Kp1+2c1Kp10.5=17.7×0×1.466+2×14.5×1.4660.5=35.117kN/m2Ppk1下=γ1(h1+H1')Kp1+2c1Kp10.5=17.7×(1+0)×1.466+2×14.5×1.4660.5=61.072kN/m2第2層土：4.5-4.54mH2'=[∑γ1h1]/γsati=[17.7]/25.31=0.699mPpk2上=γsat2H2'Kp2+2c2Kp20.5=25.31×0.699×1.466+2×14.5×1.4660.5=61.072kN/m2Ppk2下=γsat2(h2+H2')Kp2+2c2Kp20.5=25.31×(0.04+0.699)×1.466+2×14.5×1.4660.5=62.557kN/m23、支護(hù)樁受力分析沿基坑邊每延米支護(hù)樁，不同的開挖深度主動(dòng)土壓力線荷載為：qak=Pak×1沿基坑邊每延米支護(hù)樁，不同的開挖深度被動(dòng)土壓力線荷載為：qpk=Ppk×1支護(hù)樁計(jì)算簡(jiǎn)圖如下：工況1支護(hù)樁計(jì)算簡(jiǎn)圖彎矩圖(kN·m)Mk=4.025kN·m剪力圖(kN)Vk=12.795kN工況2：開挖至4.5m深度，此時(shí)所有支撐均已施工完畢開挖工況圖如下：工況2示意圖1、計(jì)算嵌固深度及支撐力大小確定根據(jù)等值梁法，通過尋找反彎點(diǎn)（支護(hù)樁彎矩為0的點(diǎn)，參考施工計(jì)算手冊(cè)可簡(jiǎn)化為土壓力合力為0的點(diǎn)即為反彎點(diǎn))，支撐看作鉸支點(diǎn)，運(yùn)用力矩分配法進(jìn)行計(jì)算。依據(jù)上述原理計(jì)算得到：支撐力R1=0kN要使板樁保持穩(wěn)定，當(dāng)前開挖工況下嵌固深度需滿足主動(dòng)土壓力造成的彎矩、基坑內(nèi)側(cè)被動(dòng)土壓力和各道支撐造成的彎矩總和平衡，即ΣM=0。同時(shí)嵌固深度需滿足《建筑基坑支護(hù)技術(shù)規(guī)程》JGJ120-2012第4.2.7條，對(duì)單支點(diǎn)支擋式結(jié)構(gòu)，嵌固深度不小于0.3倍的開挖深度，對(duì)多支點(diǎn)支擋式結(jié)構(gòu)，嵌固深度不小于0.2倍的開挖深度。根據(jù)以上條件，通過試算法得到，計(jì)算嵌固深度為t=5.38m。5.38m深度以下土壓力計(jì)算時(shí)不考慮。考慮嵌固穩(wěn)定安全系數(shù)1.2后，并滿足規(guī)范最小嵌固深度要求，當(dāng)前開挖工況支護(hù)樁實(shí)際嵌固深度7.5m≥max(1.2×5.38，0.3×4.5)=6.456m當(dāng)前工況支護(hù)樁嵌固深度滿足要求！2、當(dāng)前工況下計(jì)算嵌固深度范圍內(nèi)的土壓力計(jì)算參考《規(guī)范》JGJ120-2012，計(jì)算支護(hù)樁結(jié)構(gòu)時(shí)，只考慮彎矩平衡點(diǎn)以上部分（即：計(jì)算錨固深度范圍內(nèi)）的土壓力，所以當(dāng)前工況下只顯示錨固深度為5.38m范圍的土壓力。1）主動(dòng)土壓力計(jì)算①主動(dòng)土壓力系數(shù)Ka1=tan2(45°-φ1/2）=tan2(45-13.3/2)=0.626；Ka2=tan2(45°-φ2/2）=tan2(45-13.3/2)=0.626；Ka3=tan2(45°-φ3/2）=tan2(45-10.9/2)=0.682；Ka4=tan2(45°-φ4/2）=tan2(45-18.2/2)=0.524；Ka5=tan2(45°-φ5/2）=tan2(45-18.2/2)=0.524；②土壓力、地下水產(chǎn)生的水平荷載第1層土：0-1.5mH1'=[∑γ0h0]/γi=[0]/18.4=0mPak1上=γ1H1'Ka1-2c1Ka10.5=18.4×0×0.626-2×21.9×0.6260.5=-34.653kN/m2Pak1下=γ1(h1+H1')Ka1-2c1Ka10.5=18.4×(1.5+0)×0.626-2×21.9×0.6260.5=-17.377kN/m2第2層土：1.5-2.6mH2'=[∑γ1h1]/γsati=[27.6]/24.288=1.136mPak2上=γsat2H2'Ka2-2c2Ka20.5=24.288×1.136×0.626-2×21.9×0.6260.5=-17.377kN/m2Pak2下=γsat2(h2+H2')Ka2-2c2Ka20.5=24.288×(1.1+1.136)×0.626-2×21.9×0.6260.5=-0.654kN/m2第3層土：2.6-8.3mH3'=[∑γ2h2]/γsati=[54.317]/25.31=2.146mPak3上=γsat3H3'Ka3-2c3Ka30.5=25.31×2.146×0.682-2×14.5×0.6820.5=13.093kN/m2Pak3下=γsat3(h3+H3')Ka3-2c3Ka30.5=25.31×(5.7+2.146)×0.682-2×14.5×0.6820.5=111.476kN/m2第4層土：8.3-9mH4'=[∑γ3h3]/γsati=[198.584]/24.63=8.063mPak4上=γsat4H4'Ka4-2c4Ka40.5=24.63×8.063×0.524-2×18.5×0.5240.5=77.275kN/m2Pak4下=γsat4(h4+H4')Ka4-2c4Ka40.5=24.63×(0.7+8.063)×0.524-2×18.5×0.5240.5=86.309kN/m2第5層土：9-9.88mH5'=[∑γ4h4]/γsati=[215.825]/24.63=8.763mPak5上=γsat5H5'Ka5-2c5Ka50.5=24.63×8.763×0.524-2×18.5×0.5240.5=86.309kN/m2Pak5下=γsat5(h5+H5')Ka5-2c5Ka50.5=24.63×(0.88+8.763)×0.524-2×18.5×0.5240.5=97.666kN/m22）被動(dòng)土壓力計(jì)算①被動(dòng)土壓力系數(shù)Kp1=tan2(45°+φ1/2）=tan2(45+10.9/2)=1.466；Kp2=tan2(45°+φ2/2）=tan2(45+10.9/2)=1.466；Kp3=tan2(45°+φ3/2）=tan2(45+18.2/2)=1.908；②土壓力、地下水產(chǎn)生的水平荷載第1層土：4.5-5.5mH1'=[∑γ0h0]/γi=[0]/17.7=0mPpk1上=γ1H1'Kp1+2c1Kp10.5=17.7×0×1.466+2×14.5×1.4660.5=35.117kN/m2Ppk1下=γ1(h1+H1')Kp1+2c1Kp10.5=17.7×(1+0)×1.466+2×14.5×1.4660.5=61.072kN/m2第2層土：5.5-8.3mH2'=[∑γ1h1]/γsati=[17.7]/25.31=0.699mPpk2上=γsat2H2'Kp2+2c2Kp20.5=25.31×0.699×1.466+2×14.5×1.4660.5=61.072kN/m2Ppk2下=γsat2(h2+H2')Kp2+2c2Kp20.5=25.31×(2.8+0.699)×1.466+2×14.5×1.4660.5=164.992kN/m2第3層土：8.3-9.88mH3'=[∑γ2h2]/γsati=[88.568]/24.63=3.596mPpk3上=γsat3H3'Kp3+2c3Kp30.5=24.63×3.596×1.908+2×18.5×1.9080.5=220.136kN/m2Ppk3下=γsat3(h3+H3')Kp3+2c3Kp30.5=24.63×(1.58+3.596)×1.908+2×18.5×1.9080.5=294.402kN/m23、支護(hù)樁受力分析沿基坑邊每延米支護(hù)樁，不同的開挖深度主動(dòng)土壓力線荷載為：qak=Pak×1沿基坑邊每延米支護(hù)樁，不同的開挖深度被動(dòng)土壓力線荷載為：qpk=Ppk×1支護(hù)樁計(jì)算簡(jiǎn)圖如下：工況2支護(hù)樁計(jì)算簡(jiǎn)圖彎矩圖(kN·m)Mk=216.249kN·m剪力圖(kN)Vk=277.683kN四、支護(hù)樁、圍檁及支撐計(jì)算1、支護(hù)樁材料參數(shù)支護(hù)樁材料鋼板樁鋼板樁類別U型熱軋鋼板樁(HRSP-U)鋼板樁型號(hào)HRSP-U-2270(400×170×15.5)鋼板樁沿基坑邊方向單位長(zhǎng)度慣性矩I(cm4/m)38600鋼板樁沿基坑邊方向單位長(zhǎng)度截面抵抗矩W(cm3/m)2270鋼材的彈性模量E(N/mm2)206000鋼材的抗彎強(qiáng)度設(shè)計(jì)值f(N/mm2)205鋼材的抗剪強(qiáng)度設(shè)計(jì)值τ(N/mm2)125材料截面塑性發(fā)展系數(shù)γ1.052、圍檁材料參數(shù)圍檁材料類型槽鋼圍檁材料截面類型40b號(hào)槽鋼圍檁合并根數(shù)2根圍檁受力不均勻系數(shù)ks0.5圍檁的慣性矩I(cm4)18600圍檁的截面抵抗矩W(cm3)932圍檁的彈性模量E(N/mm2)206000圍檁的抗彎強(qiáng)度設(shè)計(jì)值f(N/mm2)205圍檁的抗剪強(qiáng)度設(shè)計(jì)值τ(N/mm2)125材料截面塑性發(fā)展系數(shù)γ1.05鋼板樁在圍檁上的荷載作用點(diǎn)間距sl(m)0.83、支撐材料參數(shù)支撐材料1：支撐材料類型大鋼管支撐材料截面類型Φ426×8支撐型鋼合并根數(shù)1根支撐抗壓強(qiáng)度設(shè)計(jì)值f(N/mm2)205支撐回轉(zhuǎn)半徑i(mm)147.8支撐截面面積A(mm2)10505支撐材料2：支撐材料類型槽鋼支撐材料截面類型40b號(hào)槽鋼支撐型鋼合并根數(shù)2根支撐抗壓強(qiáng)度設(shè)計(jì)值f(N/mm2)205支撐單根型鋼回轉(zhuǎn)半徑i(mm)27.8支撐單根型鋼截面面積A(mm2)83044、支撐水平參數(shù)支撐編號(hào)支撐計(jì)算長(zhǎng)度L0支撐方向與基坑邊緣的夾角α(度)支撐材料198984540b號(hào)槽鋼21030090Φ426×831030090Φ426×841030090Φ426×85989813540b號(hào)槽鋼序號(hào)圍檁上各支撐點(diǎn)水平間距(m)1727.737.747.757.767支撐平面布置圖5、強(qiáng)度設(shè)計(jì)值確定Mk=max(4.025，216.249)=216.249kN·mM=γ0γFMk=1.1×1.25×216.249=297.343kN·mVk=max(12.795，277.683)=277.683kN·mV=γ0γFVk=1.1×1.25×277.683=381.815kN6、材料的強(qiáng)度計(jì)算1）支護(hù)樁強(qiáng)度計(jì)算σmax=M/(γW)=297.343×106/(1.05×2270×103)=124.75N/mm2≤[f]=205N/mm2滿足要求！H`=(WH2-(H-t)2(W-2t))/(2(WH-(H-t)(W-2t))=(400×1702-(170-15.5)2×(400-2×15.5))/(2×(400×170-(170-15.5)×(400-2×15.5)))=125mmS=t(H-H`)2=15.5×(170-125)2=31388mm3,τmax=VS/(It)=381.815×31388×103/(38600×104×15.5)=2.003N/mm2≤[f]=125N/mm2滿足要求！2）圍檁強(qiáng)度計(jì)算根據(jù)最不利原則，取最大受力的開挖深度支撐層進(jìn)行計(jì)算。由前面計(jì)算可知,開挖深度范圍內(nèi)沿基坑邊單位長(zhǎng)度支護(hù)樁傳給圍檁的最大集中荷載標(biāo)準(zhǔn)值：Rmax=max(R1)=max(0)=0kN集中荷載設(shè)計(jì)值Fmax=γ0γFRmax=1.1×1.25×0=0kN由于鋼板樁在圍檁上的荷載作用點(diǎn)間距sl=0.8m，則經(jīng)過換算，即圍檁所受鋼板樁傳遞集中荷載間距為0.8m，荷載大小為Nmax=Fmax×sl=0×0.8=0kN由于圍檁合并根數(shù)為2根，則單根圍檁材料所受集中荷載標(biāo)準(zhǔn)值：Pmax=Nmax×ks=0×0.5=0kN圍檁計(jì)算簡(jiǎn)圖如下：抗彎驗(yàn)算彎矩圖最大彎矩標(biāo)準(zhǔn)值：Mk=0kN·m最大彎矩設(shè)計(jì)值：M=γ0γFMk=1.1×1.25×0=0kN·mσmax=M/(γW)=0×106/(1.05×932×103)=0N/mm2≤[f]=205N/mm2滿足要求！抗剪驗(yàn)算剪力圖最大剪力標(biāo)準(zhǔn)值：Vk=0kN最大剪力設(shè)計(jì)值：V=γ0γFVk=1.1×1.25×0=0kN·mτmax=V/(8Izδ)[bh02-(b-δ)h2]=0×1000×[102×4002-(102-12.5)×3642]/(8×186000000×12.5)=0N/mm2≤[τ]=125N/mm2滿足要求！3）支撐穩(wěn)定性計(jì)算圍檁連續(xù)