橋墩樁基礎(chǔ)設(shè)計計算書

1、基礎(chǔ)工程課程設(shè)計設(shè)計題目:某橋橋墩樁基礎(chǔ)設(shè)計計算二.設(shè)計資料：某橋梁上部構(gòu)造采用預(yù)應(yīng)力箱梁。標(biāo)準(zhǔn)跨徑30m,梁長29.9m,計算跨徑29.5m,橋面寬13m(10+2X1.5),墩上縱向設(shè)兩排支座，一排固定，一排滑動，下部結(jié)構(gòu)為樁柱式橋墩和鉆孔灌注樁基礎(chǔ)。1、水文地質(zhì)條件：河面常水位標(biāo)高25.000m,河床標(biāo)高為22.000m,一般沖刷線標(biāo)高20.000m,最大沖刷線標(biāo)高18.000m處，一般沖刷線以下的地質(zhì)情況如下：(1)地質(zhì)情況c(城軌)：序號名稱層厚土層描述天然重度丫比例系數(shù)m推薦容許承d極限摩阻力T1淤泥質(zhì)土4.6m軟塑16kN/m36MN/m450kPa20kPa2粘土3.8m灰更色

2、，硬塑317kN/m315MN/m4240kPa50kPa3碎石>50m黃色，密實20kN/m355MN/m4550kPa240kPa2、標(biāo)準(zhǔn)荷載：(1)恒載橋面自重：N1=1500kN+8X10kN=1580KN;箱梁自重：N2=5000kN+8X50Kn=5400KN;墩帽自重：N3=800kN;橋墩自重：N4=975kN;扣除浮重：10*2*3*2.5=150KN(2)活載一跨活載反力：N5=2835.75kN,在順橋向引起的彎矩：M1=3334.3kNm-；兩跨活載反力：N6=5030.04kN+8100kN;(3)水平力制動力：H=300kN,對承臺頂力矩6.5m；風(fēng)力：H2=

3、2.7kN,對承臺頂力矩4.75m3、主要材料承臺采用C30混凝土，重度丫=25kN/nf、丫='15kN/m3(浮容重)，樁基采用C30混凝土，HRB335級鋼筋；4、墩身、承臺及樁的尺寸墩身采用C30混凝土，尺寸：長嚏涓=3X2X6.5m3。承臺平面尺寸：長儂=7X4.5m2,厚度初定2.5m,承臺底標(biāo)高20.000m。擬采用4根鉆孔灌注樁，設(shè)計直徑1.0m,成孔直徑1.1m,設(shè)計要求樁底沉渣厚度小于300mm。5、其它參數(shù)結(jié)構(gòu)重要性系數(shù)乍o=1.1,荷載組合系數(shù)后1.0,恒載分項系數(shù)段=1.2,活載分項系數(shù)p=1.46、設(shè)計荷載(1) 樁、承臺尺寸與材料承臺尺寸：7.0mx4.5

4、mx2.5m初步擬定采用四根樁，設(shè)計直徑1m,成孔直徑1.1m。樁身及承臺混凝土用30號，其受壓彈性模量Eh=3x104MPa。(2) 荷載情況上部為等跨30m的預(yù)應(yīng)力箱梁橋，混凝土橋墩，作用在承臺底面中心的荷載為：恒載及一孔活載時：N1.2(1580540080097515074.52.515)1.42835.7515713.55KNH1.4(3002.7)423.78KNM3334.3300(2.56.5)2.7(4.752.5)1.48475.425KN恒載及二孔活載時：N1.2(1580540080097515074.52.515)+1.45830.04=19905.556KN樁(直徑

5、1m)自重每延米為：冗12一q=1511.781KN/m(已扣除浮力)4三、計算1、根據(jù)公路橋涵地基與基礎(chǔ)設(shè)計規(guī)范反算樁長根據(jù)公路橋涵地基與基礎(chǔ)設(shè)計規(guī)范中確定單樁容許承載力的經(jīng)驗公式，初步反算樁的長度，設(shè)該樁埋入最大沖刷線以下深度為h,一般沖刷線以下深度為h2,則：NhlEi入m°A&k2丫2(h23)19905.556Nh4土換算加權(quán)重度1NhPU24.6203.8一一2986(1098)h250(h(h1)m0A(r0k2Y2(h23)0.53.4564.63.8)2400.70.80.7855501147.916h3829.416)樁的設(shè)計樁徑1m,沖抓錐成孔直徑為1.

6、1m,樁周長和面積為_12U=兀x1.1=3.456m,0.785m，假定樁長<20m取入=0.70t/d<0.3取mo=0.804查表得k2=6.0已知0=550KPaqIo0.5qh5058.8565.891h164.6173.8(h24.63.8)20_29.81010h2h2Nh435.205h26218.554h13947.1280h16.26m(舍去負(fù)值)現(xiàn)取h=17m<20m,滿足取入=0.70,則，樁低標(biāo)高為1.00m2.單樁豎向允許承載力代入數(shù)據(jù)h=17m得_1、P-Ul再入m0A5k2T2(h23)5480.67KN2加權(quán)重度2104至10工988.432

7、KN/m3h21723、樁的平面布置圖25.00m常水位22.00mW床20.00mr-般沖刷線18.00mM大沖刷線052501.00m樁底標(biāo)高10040010045050100300承臺平面布置圖5010a50承臺橫橋向立面圖承臺縱橋向立面圖4、樁的內(nèi)力及位移計算(1)確定樁的計算寬度blbiKfK0Kd0.9(d1)k,Q沿水平力H作用方向上裝間凈距1b11.381m,1bLiL11.5m0.6h10.63(d1)3.6m,Kb10.767m,0.6h1滿足nb12.762B114.5,取一排裝兩邊外側(cè)邊緣距離B13.5m地面或最大沖刷線下的影響深度hm2(d1)4m范圍內(nèi)有兩層土。0.

8、67Eh0.673107便。即次m0mh1m2(2hh2)h262.6計算樁-土變形系數(shù)15(22.61.4)1.442211197.5KN/mh24m_724_42.0110KN/m,Id0.0491m，64h7.4122.5,滿足按彈性樁計算(3)樁頂剛度系數(shù)1、2、3、4的計算._一_.221020182m,h17m,0.5,A-d0.785m4Comoh11197.5175321.90410KN/m,Ao2.5424.91m2(按樁中心距計算)已知:h20.5170.7853107115_56.60100.670EI1.9041054.91查表得:AEhh7.4124,取用4,1l00

9、.43620.872mq0.48395m0.64916m1.25357EIM0.5466EI3_23EIQ0.0401EI,32EIM0.1234EI,4(4)計算承臺地面遠點O處位移0、b。、0(單孔活載+恒載+制動力),N15713.555863.26b0n140.670EIEIm2_2一n41Xm40.5466EI0.67EI41.256.3739EIi1n240.0401EI_22_20.1604EI,n340.1234EI0.4936EI,n30.2436(EI)in41XHn3Mi1a0i22n2n41xn3i16.3739EI423.780.4936EI8475.4258840.

10、310.1604EI6.3739EI0.0.2436(EI)2EIn2Mn3Hm22n2n41Xi(n3)i10.1604EI8475.4250.4936EI8475.4252014.24ZZ_2Z0.1604EI6.3739EI0.0.2436(EI)EI(5)計算作用在每根樁頂上的作用力Pi、Qi、Mi豎向力P1b00.670EI5863.26EI1.252014.24EI5615.31KN2241.46KN,一884031201424水平力Q20300.0401EI0.1234EI105.94KN2030EIEI2014.248840.31彎矩Mi403ao0.5466EI0.1234E

11、I10.09KNm14030EIEI校核：nQ4105.94KN423.76KNH423.78KNn8475.425KNmXRnMi2(5615.312241.46)1.25410.098474.985KNmMi1nRi12(5615.312241.46)15713.54KNP15713.55KN校核正確(6)計算最大沖刷線處樁身彎矩M0,水平力Q及軸向力P05615.310.7852155641.86KN叫MiQil010.09QQi105.94KN,P0105.942221.97KNm(7)最大彎矩Mmax及最大彎矩位置Zmax的計算0.436m1,h7.4124(取4)CQM00.436

12、221.97-0.9135Q。105.94查表得：ZZ0.97838,ZJmax0.978382.244m0.436可查表(線性內(nèi)插)得KM1.666MmaxM0KM221.971.463369.80KNm(8)樁頂縱向水平位移驗算樁在最大沖刷線處水平位移X。和轉(zhuǎn)角()o的計算查表得：A2.44066,Bx1.62100,A1.62100,B1.75058、，Qo“Mo-105.94-221.97Xo3oA2Bx32.440662-1.62100EIEI0.436EI0.436EI一一一33.21103m3.21mm6mm,符合規(guī)范要求QoMo105.94/、221.973O2°AB

13、2(1.62100)+(1.75058)1.8210radEIEI0.436EI0.436EI樁頂縱向水平位移_QAO2eiaMoBEI100lo105.94221.97.2(1.62100+(0.436EI0.436EI33Ql33.2110(1.8210)20EI1.75058)1.82103radMl：3君(6.850.31)10m7.16mm水平位移容許值=0.5J25=2.5cm=25mm符合規(guī)范要求。5、按m法計算樁身入土段任一深度處的彎矩和樁側(cè)橫向土抗力（并作MZ:Z、Z:Z曲線）已經(jīng)算出b1.381m,0.436m1,Q105.94KN,M）221.97KNm1ZZ曲線，ZX告

14、ZAx魯ZBxZZZAxBxQlZAxb12M0ZBb1ZBxZX002.440661.6210000.2293580.12.278731.450947.62166823114.43320207612.0548710.4587160.22.117791.2908814.166744437.88830950422.0550510.9174310.41.802731.0006424.1183641212.2294218236.347791.3761470.61.502680.74981307458168443.901911.8348620.81.22370.5372732

15、.74327512113.1325980645.8758712.29357810.970410.3611932.4573032711.0357992643.49313.4403671.50.466140.0628823.3864768712.8818532826.2683314.58715620.14696-0.075729.83074224-4.627097765.20364415.9633032.6-0.03986-0.11136-3.466313292-8.846482944-12.31286.8807343-0.08741-0.09471-8.77080681-8.68130802-1

16、7.45218.0275233.5-0.10495-0.05698-12.285919281-6.09338422-18.379319.1743124-0.10788-0.01487-14.43304944-1.81735192-16.2504“Q2Mn-Q1z：Z®線，ZXZAZB<,2Mz:Z曲線，Mz9AmM°BmnnZZZAMBmQ0AAMM0BmMz00010221.97221.970.2293580.10.09960.9997424.200808221.9122878246.11310.4587160.20.196960.9980647.857340822

17、1.5393782269.39670.9174310.40.377390.9861791.6982222218.9001549310.59841.6055050.70.592280.93817143.9121944208.2455949352.15782.064220.90.689260.88407167.4763948196.2370179363.71342.5229361.10.747140.8141181.5400772180.705777362.24593.2110091.40.764980.68694185.8748404152.4800718338.35493.6697251.60

18、.737340.59373179.1588732131.7902481310.94915.0458722.20.53160.32025129.16816871.0858925200.25415.9633032.60.354580.1754686.155848438.9468562125.10276.88073430.193050.0759546.90728916.858621563.765918.0275233.50.050810.0135412.34581383.005473815.351299.17431240.000050.000090.0121490.01997730.0321266、

19、樁身界面配筋計算(1)配筋的計算最大彎矩發(fā)生在Z=2.082m處，此處設(shè)計最大彎矩為Mj369.80KNm最大設(shè)計豎向力為NjP00.5qZ0.5UZMje066.3mm,又h0Nj5641.860.511.7810.5202.0823.4565580.718KNh7.412(4),計算長度lp0.5(240.4365.5874.4故需要考慮縱向彎曲對偏心距的影響系數(shù)e0，66.33又hh7.4124),計算長度lp0.5(2總藐)5.5874.41lelc一1(-)212,10.22.7e0,21.150.01-1,而l05.5871400曳hh0hh0h0rrs5000.9500950mm

20、h1000mni代入得：i0.364,21.0841取1,1.132e075.1mnu0.5m,C30昆凝土HRBffl筋R17.5Mp,Rg340MP,偏心距系數(shù)Ere00.132MjJ2958.43rN一一，軸力系數(shù)Nrj22322.872彎貨!系數(shù)ENrr若取g=0.9,查墩臺與基礎(chǔ)附表得以下表格數(shù)據(jù)實際偏心系數(shù)E-2表中偏心系數(shù)E相應(yīng)E配筋率NrNENrEN1.1320.13440.9800.00222322.87367662958.44943.20.12880.9800.004383904943.20.13570.9600.006393045334.90.13030.9600.008

21、409275334.9當(dāng)u=0.006和u=0.008時均有N>Nr,EN>ENr,故樁身只需要按構(gòu)造配筋，取u=0.006縱筋A(yù)gur24712.39mm2現(xiàn)采用12_22，實配Ag188424562mm2(2)對截面進行強度校核As2r層厚度C6545620.58%0.5%M%65mmM中rs(500)2254mm50mm縱向鋼肋間距91.9mm2435mmg區(qū)0.87昆凝土保護r80mml滿足要求，布置如下圖所示(3)驗算垂直于彎矩作用平面內(nèi)承載力2801034562)”,11.232s°NuG(fcdAhfsdAg)Nu(13.8103-121.1413217.3

22、KNNj5580.718KN滿足要求7、承臺設(shè)計(1)樁與承臺的連接處構(gòu)造設(shè)計承臺平面尺寸：長儂=7X4.5m2,厚度2.5m,承臺底標(biāo)高20.000m。采用樁頂主筋伸入承臺連接。樁身嵌入承臺內(nèi)的深度為200mm；伸入承臺內(nèi)的樁頂主筋做成喇叭狀，夾角15度。伸入承臺內(nèi)的主筋豎向高度為100cm>35*2.2=77cm,不設(shè)彎鉤的帶肋鋼筋?？箯濅摻畈贾迷诔信_內(nèi)上下兩排并且不截斷穿過樁身。箍筋設(shè)20箍_10,間距200mm,構(gòu)造鋼筋前后兩端各18根_10,抗裂鋼筋前后兩端各8根_12下設(shè)相同的鋼筋網(wǎng)具體配筋圖見附圖Bo(2)樁頂局部受壓驗算樁頂局部受壓時按右式計算PjAcRa/m式中Fj承臺

23、內(nèi)基樁承受計算軸向力，PjNj5580.718KN,1,Ac-120.785mm實配鋼筋A(yù)sy15282mm,保護層厚度7cm,沿x軸布置，具體配筋圖件附圖四、參考資料及應(yīng)用軟件1.公路橋涵設(shè)計通用規(guī)范JTGD60-2004;2.公路橋涵地基與基礎(chǔ)設(shè)計規(guī)范JTGD63-2007;,橋梁C30昆凝土R220.1MP,系數(shù)m1.544AcR2/m10.78520.1103/1.5410245.78KNNj5580.718KN,滿足要求，可按構(gòu)造配筋(3)承臺受沖切驗算樁邊沖切，相關(guān)參數(shù)見樁平面布置圖B,計算沖承臺有效高度h0=250-20-4=276cm,跨比0xa0xh00.84500.2212260yC30混凝土1.995C11.9950.2HRB鋼筋取(10.25)0yfta0yh00.84252260.111，計算沖切系數(shù):0y0.22.701,Qh25002000,取hp0.91.390MP,貝U20x(bca0y)0y(hcaox)hpfth02.701(2.50.5)0.91390C2150cma”50cm,a1y25cm,計算沖切系數(shù)hp0.9Nj1x(c20.913902.2414888.30.5a1y)1y