CFG樁復(fù)合地基處理工程計(jì)算書2

/計(jì)算書：1、面積置換率計(jì)算依據(jù)《建筑地基處理技術(shù)規(guī)范》（79-2012），式中：——復(fù)合地基承載力特征值，取值為180；——單樁承載力發(fā)揮系數(shù)，取0.80；——樁端端阻力發(fā)揮系數(shù)，取1.0；——面積置換率；——單樁承載力特征值（）；——樁截面積，0.09616m2（樁徑0.35m）；——樁間土強(qiáng)度的發(fā)揮系數(shù)，按規(guī)范取0.90；——處理后樁間土承載力特征值，取值60（樁間土按素填土取值）；——樁的周長(zhǎng)；——樁側(cè)土側(cè)阻力特征值；——第i層土的厚度；——樁端端阻力特征值，（以可塑粘土、硬塑粘土、強(qiáng)風(fēng)化泥質(zhì)砂巖作為樁端持力層）。單樁承載力計(jì)算和取值表代表性孔指標(biāo)土層層厚樁側(cè)土側(cè)阻力特征值（）樁端端阻力特征值（）單樁承載力特征值（）1素填土0.1212/267.79軟塑粉質(zhì)粘土1.9025/硬塑粘土2.48459503附近23軸線素填土1.4012/264.77可塑粉質(zhì)粘土2.9030/硬塑粘土1.20459504附近36軸線素填土1.4012/264.77硬塑粘土2.80459505素填土2.1312/261.38硬塑粘土2.87459507素填土5.0512/274.31可塑粘土4.45353808素填土3.0512/228.70可塑粘土3.953538011硬塑粘土2.5045950214.9912素填土1.9412/267.72可塑粘土2.2035/軟塑粉質(zhì)粘土1.4025/硬塑粘土0.564595014素填土1.8012/273.34硬塑粘土3.2045950取值=200取=200進(jìn)行計(jì)算。180≤0.8×m×200/0.09616+0.9×(1)×6012.12≤154.81mm≥0.07830.0783，則單根樁承擔(dān)的處理面積0.09616/0.0783≈1.228m2。2、樁位布置2/2式中：m——實(shí)際置換率；n——同一承臺(tái)內(nèi)樁數(shù)量；——樁截面積，0.09616m2（樁徑0.35m）；A——承臺(tái)面積；d——樁身平均直徑(m)；——一根樁分擔(dān)的處理地基面積的等效直徑(m)；正方形布樁1.13s，矩形布樁1.13，s、s1、s2分別為樁間距、縱向樁間距和橫向樁間距。樁復(fù)合地基設(shè)計(jì)樁布置樓號(hào)序號(hào)承臺(tái)類型承臺(tái)尺寸()樁位間距()樁徑一個(gè)承臺(tái)樁根數(shù)實(shí)際置換率m樁頂標(biāo)高（±0標(biāo)高下）1#樓1011900x19001100x11003504根0.1065-2.10m(局部2.6m)2022400x2400900x13003506根0.10013032700x3200950x11003509根0.10014042300x3600850x13003509根0.104550510400x39001100x110035040根0.09486063000x41001100x110035012根0.09387072500x4000950x110035012根0.11538083100x44001150x90035015根0.10579094300x55001150x95035024根0.097510102800x43001000x120035012根0.095811113000x47001150x100035015根0.102212122100x21001100x11003505根0.10902#樓1011900x19001100x11003504根0.1065-1.60m2022400x2400900x13003506根0.10013032800x28001000x10003509根0.11034041300x1300800x8003504根0.227550510400x39001100x110035040根0.09486063000x41001100x110035012根0.09387072500x4000950x110035012根0.11538083100x44001150x90035015根0.10579092300x3600850x13003509根0.104510102800x43001000x120035012根0.095811112300x5400850x120035015根0.116112124300x55001150x95035024根0.097513132700x3200950x11003509根0.100114142300x3600850x13003509根0.104515151900x34001100x9003508根0.1190以上布樁均滿足式中：m——實(shí)際置換率；m——實(shí)際置換率；n——同一承臺(tái)內(nèi)樁數(shù)量；——樁截面積，0.09616m2（樁徑0.35m）；A——承臺(tái)面積。根據(jù)以上單樁承載力計(jì)算可知，按上表樁間距布置樁，有效最短樁長(zhǎng)不應(yīng)小于2.5m，才能滿足上部荷載的要求，復(fù)合地基承載力特征值≥200。3、樁體強(qiáng)度選擇依據(jù)《建筑地基處理技術(shù)規(guī)范》（79-2012）式中：——樁體混合料試塊28d立方體抗壓強(qiáng)度平均值?！獑螛冻休d力發(fā)揮系數(shù)，取0.80；——樁截面積，0.09616m2（樁徑0.35m）——單樁承載力特征值200（）；經(jīng)計(jì)算：≈6655.57，因成樁工藝選用長(zhǎng)螺旋中心壓灌成樁，故選用C20砼。4、復(fù)合地基承載力驗(yàn)算(1)根據(jù)式中：m——實(shí)際置換率；n——同一承臺(tái)內(nèi)樁數(shù)量；——樁截面積，0.09616m2（樁徑0.35m）；A——承臺(tái)面積；并根據(jù)各類型基礎(chǔ)樁布樁形式及樁距，經(jīng)計(jì)算，復(fù)合地基面積置換率m值均可滿足設(shè)計(jì)要求；(2)復(fù)合地基承載力驗(yàn)算式中：——復(fù)合地基承載力特征值；——單樁承載力發(fā)揮系數(shù)，取0.80；——面積置換率，計(jì)算時(shí)取實(shí)際置換率，見布樁大樣圖；——單樁承載力特征值（）；——樁截面積，0.09616m2（樁徑0.35m）；——樁間土強(qiáng)度的發(fā)揮系數(shù)，按規(guī)范取0.90；——處理后樁間土承載力特征值，取值60（樁間土按素填土取值）；復(fù)合地基承載力計(jì)算結(jié)果見下表。復(fù)合地基承載力計(jì)算結(jié)果表樓號(hào)基礎(chǔ)型號(hào)實(shí)際面積置換率m單樁承載力特征值（）按最不利考慮處理后的樁間土承載力特征值（）按最不利考慮單樁承載力發(fā)揮系數(shù)λ樁間土強(qiáng)度發(fā)揮系數(shù)?復(fù)合地基承載力特征值（）1#樓010.1065264.77600.800.90282.84020.1001269.70600.800.90273.20030.1001274.40600.800.90277.11040.1045260.16600.800.90274.54050.0948267.10600.800.90259.54060.0938274.30600.800.90262.99070.1153278.10600.800.90314.54080.1057228.43600.800.90249.17090.0975261.81600.800.90261.10100.0958245.06600.800.90244.14110.1022228.43600.800.90242.70120.1090261.74600.800.90285.472#樓010.1065214.99600.80.9238.74020.1001224.88600.80.9235.87030.1103262.58600.80.9289.00040.2275257.19600.80.9528.49050.0948264.67600.80.9257.62060.0938334.78600.80.9310.19070.1153273.35600.80.9309.98080.1057364.89600.80.9369.16090.1045265.44600.80.9279.13100.0958295.36600.80.9284.23110.1161340.75600.80.9376.86120.0975272.62600.80.9269.87130.1001219.94600.80.9231.76140.1045224.88600.80.9243.86150.1190323.22600.80.9367.57根據(jù)計(jì)算結(jié)果，其加固后的復(fù)合地基承載力特征值均大于180。滿足設(shè)計(jì)要求。5、壓縮模量地基處理后的變形計(jì)算應(yīng)按現(xiàn)行的國(guó)家標(biāo)準(zhǔn)《建筑地基處理技術(shù)規(guī)范》（79-2012）的有關(guān)規(guī)定執(zhí)行，復(fù)合地基的壓縮模量等于該天然地基壓縮模量ξ倍，按勘察報(bào)告提供的樁間土承載力特征值（素填土）60。ξ（為處理后的復(fù)合地基承載力，ξ為壓縮模量提高系數(shù)）,各土層處理后的壓縮模量詳見表6。復(fù)合地基沉降和變形計(jì)算本工程根據(jù)場(chǎng)地地質(zhì)條件和上部結(jié)構(gòu)荷載選取最不利位置進(jìn)行估算。根據(jù)《建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范》(50007-2011)，《建筑地基處理技術(shù)規(guī)范》（79-2012）公式：，，，計(jì)算變形量；式中：——地基最終變形量()；——按分層總和法計(jì)算出的地基變形量()；——沉降經(jīng)驗(yàn)系數(shù)，根據(jù)變形計(jì)算深度范圍內(nèi)壓縮模量的當(dāng)量值()、基底附加壓力按《建筑地基處理技術(shù)規(guī)范》（79-2012）表7.1.8取值；N——地基變形計(jì)算深度范圍內(nèi)所劃分的土層數(shù)；——相應(yīng)于作用的準(zhǔn)永久組合時(shí)基礎(chǔ)底面處的附加壓力()；——基礎(chǔ)底面下底i層土的壓縮模量()；——基礎(chǔ)底面至第i層土、第1層土底面的距離(m)；——基礎(chǔ)底面計(jì)算點(diǎn)至第i層土、第1層土底面范圍內(nèi)平均附加應(yīng)力系數(shù)；——壓縮模量當(dāng)量值；——第i層土附加應(yīng)力系數(shù)沿土層厚度的積分值；——變形計(jì)算深度，應(yīng)大于復(fù)合土層的深度(m)，計(jì)算深度范圍內(nèi)遇基巖時(shí)取至基巖表面；b——基礎(chǔ)寬度(m)；——在計(jì)算深度范圍內(nèi)，第i層土的計(jì)算變形值(m)；——在計(jì)算深度范圍內(nèi)向上取厚度為的土層計(jì)算變形值，按《建筑地基基礎(chǔ)設(shè)計(jì)規(guī)范》(50007-2011)表5.3.6取值(m)。沉降、相鄰柱基沉降差計(jì)算表6-1計(jì)算項(xiàng)目土層P0()(m)()()壓縮模量()計(jì)算壓縮模量值()模量提高系數(shù)ζ4)()ψs()S()沉降差0.002L1#樓5剖面35軸線素填土18012.1603192.9015.425.321.640.24881.632114.020.44106.2546.754.775.50硬塑粘土19010.3154.855.323.750.24021.9709可塑粉質(zhì)粘土1206.2433.205.325.350.22891.2955硬塑粘土19010.3154.855.326.200.22230.6146硬塑粘土19010.3110.311.008.280.20501.2766粉土1105.425.421.0012.100.17131.48761#樓5剖面36軸線素填土1809.8602872.9013.874.781.400.24911.395013.870.4495.4141.98硬塑粘土19010.3149.284.785.000.22853.1750硬塑粘土19010.3110.311.007.600.20591.6894粉土1105.425.421.009.800.18751.09062#樓11剖面7軸線素填土18014.0603242.9015.665.401.970.24851.958214.230.43122.8252.816.897.00可塑粘土1307.2839.315.402.780.24650.7829硬塑粘土19010.3155.675.403.540.24310.7012可塑粘土1307.2839.315.404.890.23371.1289軟塑粉質(zhì)粘土803.7620.305.405.900.23070.8733硬塑粘土19010.3155.675.407.500.21941.1375硬塑粘土19010.3110.311.0010.600.19421.6521粉土1105.425.421.0014.000.17341.47632#樓11剖面9軸線素填土18016.0603482.9016.825.801.980.24831.966513.290.46129.8059.71可塑粘土1307.2842.225.802.30.24650.3013硬塑粘土19010.3159.805.804.40.23561.8788可塑粘土1307.2842.225.805.10.23260.5985軟塑粉質(zhì)粘土803.7621.815.805.90.22580.5838硬塑粘土19010.3159.805.806.50.22060.4067硬塑粘土19010.3110.311.0010.60.18692.1890粉土1105.425.421.00160.14971.6562經(jīng)計(jì)算：相鄰柱基的沉降差≤0.002L(L為相鄰柱間距)，滿足規(guī)范要求。沉降、整體傾斜計(jì)算表6-2計(jì)算項(xiàng)目土層P0()(m)()()壓縮模量()計(jì)算壓縮模量值()模量提高系數(shù)ζ4)()ψs()S()沉降差整體沉降差1#樓1剖面H軸線素填土18013.0602902.9014.024.830.140.24990.139911.050.55113.6862.523.800.0003軟塑粉質(zhì)粘土803.7618.164.832.020.24481.8380硬塑粘土19010.3149.804.834.500.22071.9946硬塑粘土19010.3110.311.005.900.20430.8489粉土1105.425.421.0013.000.13422.15691#樓1剖面A軸線素填土18017.0602662.9012.864.432.100.24642.069811.760.52127