隧道工程課程設(shè)計(jì)

頁眉頁眉頁腳頁腳1初始條件某一級(jí)公路隧道通過IV類圍巖（即川級(jí)圍巖），埋深H=20m，隧道圍巖天然容重Y25KN/m3,計(jì)算摩擦角巾=50o,變形模量E=10GPa,采用礦山法施工。； 襯砌材料采用C25噴射混凝土，材料容重h22KN/m3,變形模量Eh25GPa2隧道洞身設(shè)計(jì)2.1隧道建筑界限及內(nèi)輪廓圖的確定該隧道橫斷面是根據(jù)兩車道一級(jí)公路 III級(jí)圍巖來設(shè)計(jì)的，根據(jù)《公路隧道設(shè)計(jì)規(guī)范》確定隧道的建筑限界如下：W一行車道寬度；取3.75X2mC—余寬；因設(shè)置檢修道，故余寬取為 0mJ一檢修道寬度；雙側(cè)設(shè)置，取為1.0X2mH一建筑限界高度；取為5.0mLl一左側(cè)向?qū)挾龋蝗?.0mLr一右側(cè)向?qū)挾龋蝗?.0mEl一建筑限界左頂角寬度；取1.0mEr一建筑限界右頂角寬度；取1.0mh一檢修道高度；取為0.25m隧道凈寬為1.0+1.0+7.50+1.0+1.0=11.5m設(shè)計(jì)行車速度為80km/h,建筑限界左右頂角高度均取1m;隧道輪廓線如下圖：10Q121010Q1210lflQ■igLUllOQMQLZfifl圖1 隧道內(nèi)輪廓限界圖（單位cm）根據(jù)規(guī)范要求，隧道襯砌結(jié)構(gòu)厚度為 45cm（一次襯砌為10cm和二次襯砌35cm）通過作圖得到隧道的尺寸如下:圖2隧道內(nèi)輪廓圖得到如下尺寸：R!7.00m,R25.98m）R310.6m3隧道襯砌結(jié)構(gòu)設(shè)計(jì)支護(hù)方法及襯砌材料根據(jù)《公路隧道設(shè)計(jì)規(guī)范》(JTG-2004),本設(shè)計(jì)為一級(jí)公路，采用復(fù)合式襯砌，復(fù)合式襯砌是由初期支護(hù)和二次襯砌及中間防水層組合而成的襯砌形式。復(fù)合式襯砌應(yīng)符合下列規(guī)定：1初期支護(hù)宜采用錨噴支護(hù)，即由噴射混凝土，錨桿，鋼筋網(wǎng)和鋼筋支架等支護(hù) 形式單獨(dú)或組合使用，錨桿宜采用全長(zhǎng)粘結(jié)錨桿。2二次襯砌宜采用模筑混凝土或模筑鋼筋混凝土結(jié)構(gòu)，襯砌截面宜采用連結(jié)圓順 的等厚襯砌斷面，仰拱厚度宜與拱墻厚度相同。由規(guī)范842-1,對(duì)于兩車道川級(jí)圍巖：初期支護(hù)：拱部邊墻的噴射混凝土厚度為 8-12cm,拱墻的錨桿長(zhǎng)度為2.5-3m,錨桿間距為1.0-1.2m;二次襯砌厚度：拱墻混凝土厚度為35cm因此確定襯砌尺寸及規(guī)格如下：深埋隧道外層初期支護(hù)，根據(jù)規(guī)范規(guī)定，采用錨噴支護(hù)，錨桿采用普通水泥砂漿錨桿，規(guī)格HRB20X2.5m,采用梅花型局部布設(shè)，采用C25噴射混凝土。初次襯砌：采用C25噴射混凝土，厚度為9.8cm。防水板：采用塑料防水板及無紗布，且無紡布密度為 300g/m2,防水板應(yīng)采用鋪滿的EVA板防水層，厚度為2.0mm,搭接長(zhǎng)度為150mm。二次襯砌：根據(jù)《公路隧道設(shè)計(jì)規(guī)范》，采用C25號(hào)模筑防水混凝土，厚度為35cm。整個(gè)襯砌厚度為9.8+0.2+35=45cm隧道深淺埋的確定及圍巖壓力的計(jì)算隧道的內(nèi)輪廓尺寸為B=12.10m,H=10.50m因?yàn)镮V級(jí)圍巖需要預(yù)留變形量，查《公路隧道設(shè)計(jì)規(guī)范》 8.4.1知川級(jí)圍巖需預(yù)留變形量為20-50mm,襯砌厚度為45cm,又每側(cè)超挖量為10cm,故隧道的近似開挖尺寸為：Bt12.1020.4520.10.0513.25mHt10.5020.4520.10.0511.65m由于是川級(jí)圍巖Hp2hqHp—深淺埋隧道的分界深度hq0.452S1hq一等效荷載高度一跨度影響系數(shù)； 1i(Bt5)i一圍巖壓力增減率，當(dāng)Bt5-15m取i=0.1hq0.452s-1 0.4523-1[10.1(13.255)]3.285mHp2hq2.5 3.285 8.213m埋?H30Hp8.213m故為深埋隧道又號(hào)11.650.881.713.25可用公式qhq計(jì)算均布垂直壓力:qhq253.28582.125kN/m2因?yàn)樵撍淼绹鷰r級(jí)別為川圍巖水平均布?jí)毫椋篹<0.15q=0.1582.125=12.324襯砌結(jié)構(gòu)內(nèi)力計(jì)算

基本資料公里等級(jí) 一級(jí)公路圍巖級(jí)別 川級(jí)圍巖容重彈性抗力系數(shù)變形模里材料容重材料變形模量襯砌厚度r=25KN/m3K=0.18X106KN/mE=10GPah22KN/m3Eh25GPad=0.45m圖3 襯砌結(jié)構(gòu)斷面圖荷載的確定圍巖壓力的確定經(jīng)前面計(jì)算可得，可用公式qhq計(jì)算均布垂直壓力q hq253.28582.125kN/m2JII級(jí)圍巖不考慮一襯后的圍巖釋放變形折減系數(shù)422襯砌自重TOC\o"1-5"\h\z1 2g-(dodn)h-(0.450.45)229.9KN/m22(1)全部垂直荷載q=82.125+9.9=92.025KN/m 2(2)圍巖水平均布?jí)毫<0.15X92.025=13.80KN/m24.3襯砌幾何要素襯砌的幾何尺寸內(nèi)輪廓線半徑：Ri7.00m,R25.98m內(nèi)徑「1,d所畫圓曲線端點(diǎn)截面與豎直軸線的夾角43.073268.410拱頂截面厚度do0.45m,拱底截面厚度dn0.45m半拱軸線長(zhǎng)度S及分段軸長(zhǎng)S用"(7.00四)68^^(5.9845P)12.78m18021802將半拱軸長(zhǎng)度等分為8段，則SS—1.598m8S1.598 ?8- 6.3910Eh251064.4計(jì)算位移單位位移4-1用辛普生法近似計(jì)算，按計(jì)算列表進(jìn)行，單位位移的計(jì)算列表見表4-1表4-1單位位移計(jì)算表

asinaCOSaxyd1/Iy/Iy2/I2(1+y)/I積分系數(shù)1/300.0000.0001.0000.0000.0000.450131.6870.0000.000131.6871114.7600.2550.9671.5840.1990.450131.68726.2065.215189.3144229.5200.4930.8703.0560.8060.450131.687106.14085.549429.5162344.2800.6980.7164.3311.7560.450131.687231.243406.0621000.2354459.0400.8580.5145.3203.0120.450131.687396.6421194.6862119.6572573.5720.9590.2835.9824.5310.450131.687596.6752703.5344028.5714686.2090.9980.0666.2636.1070.450131.687804.2144911.3356651.4502798.8460.988-0.1546.1947.7000.450131.6871013.9927807.7379967.40748111.4830.931-0.3665.7739.2320.450131.6871215.73711223.68113786.8411刀1053.4983767.39622432.33731020.628注：1I——截面的慣性矩，I=bd3/12,b取單位長(zhǎng)度2不考慮軸力影響單位位移值計(jì)算如下:SEhSEh-6.3910 1053.4986.73210Iy -8 -512 6.3910 3767.396 24.07410EhIK6.3910-822432.337143.34310-5I22Eh計(jì)算精度校核:112121121222 (6.732 24.074 2 143.343)10-5198.223 10SSEh6.3910-831020.628198.2210SSEh6.3910-831020.628198.2210-5閉合差0.003105 04.4.2—位移一一主動(dòng)荷載在基本結(jié)構(gòu)中引起的位移1）每一塊上的作用力（豎向力Q、水平力E、自重力G）,分別由下面各式求得Qi=qxbE=exhiGi=(d'+dWSE=exhiGi=(d'+dWSxrh其中：bi——襯砌外緣相鄰兩截面間的水平投影長(zhǎng)度hi--—--襯砌外緣相鄰兩截面間的豎直投影長(zhǎng)度di——接縫i的襯砌截面厚度均由圖3直接量得，其值見表4-2。各集中力均通過相應(yīng)圖形的形心Q40362 *Q1E138發(fā)位移計(jì)算表截面投影長(zhǎng)度集中力S-Qaq△g△gbhQGEaqagae00.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.00011.5800.200145.40015.8202.7610.7900.7900.100-114.866-12.498-0.27621.4760.600135.82915.8208.2820.7380.7380.300-100.242-11.675-2.48531.2740.957117.24015.82013.2100.6370.6370.479-74.682-10.077-6.32140.9891.25091.01315.82017.2550.4950.4950.625-45.006-7.823-10.78450.6601.52360.73715.82021.0230.3300.3300.762-20.043-5.221-16.00960.2801.57025.76715.82021.6720.1400.1400.785-3.607-2.215-17.01370.0701.5936.44215.82021.990-0.035-0.0350.7970.2250.554-17.51580.4171.53938.37415.82021.244-0.209-0.2090.7708.0013.299-16.348續(xù)表4-2Ei-1(Q+G)刀i-1ExyAA-Ax刀i-1(Q+G)-勺刀i-1EMoip0.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0001.5840.1991.5840.1990.0000.000-127.640161.2202.7613.0560.8061.4720.607-237.315-1.676-481.033312.86911.0434.3311.7561.2750.950-398.908-10.491-981.512445.92924.2545.3203.0120.9891.256-441.024-30.463-1516.611552.76241.5095.9824.5310.6621.519-365.928-63.052-1986.864629.31862.5326.2636.1070.2811.576-176.838-98.551-2285.088670.90684.2046.1947.700-0.0691.59346.292-134.138-2389.669693.168106.1945.7739.232-0.4211.532291.824-162.689-2265.5832）外荷載在基本結(jié)構(gòu)中產(chǎn)生的內(nèi)力塊上各集中力對(duì)下一接縫的力臂由圖直接量得，分別記以 aq、ae、ag內(nèi)力按下式計(jì)算之：Mf MioMf Mioi,p Xi (QG)i1yEQ?aqGagEai1軸力:Nipsini(QG)cosii式中A(i>Ayi-相鄰兩接縫中心點(diǎn)的坐標(biāo)增值A(chǔ)Xi=Xi-Xi-1勾i=yi-yi-iM[p和N[p的計(jì)算見表4-3及表4-4。表4-3載位移N.p計(jì)算表截面asinaCOSaEi(Q+G)EiEsina*Ei(Q+G)cosa*EiENop00.0000.0001.0000.0000.0000.0000.0000.000114.7600.2550.967161.2202.76141.0742.67038.404229.5200.4930.870312.86911.043154.1599.610144.549344.2800.6980.716445.92924.254311.33217.364293.968459.0400.8580.514552.76241.509474.00821.354452.654573.5720.9590.283629.31862.532603.62717.685585.942686.2090.9980.066670.90684.204669.4385.567663.870798.8460.988-0.154693.168106.194684.923-16.330701.2538111.4830.931-0.366747.362127.439695.440-46.671742.1113）主動(dòng)荷載位移計(jì)算過程見表4-4表4-4主動(dòng)荷載位移計(jì)算表截面Mp01/Iy/i1+yMp0/lyMp0/lMp0(1+y)/l積分系數(shù)1/300.000131.6870.0001.0000.0000.0000.00011-127.640131.68726.2061.199-16808.513-3344.894-20153.40742-481.033131.687106.1401.806-63345.857-51056.761-114402.61823-981.512131.687231.2432.756-129252.583-226967.536-356220.12044-1516.611131.687396.6424.012-199718.354-601551.682-801270.03625-1986.864131.687596.6755.531-261644.675-118551269846-2285.088131.687804.2147.107-300916.979-1837699.993-2138616.97227-2389.669131.6871013.9928.700-314688.937-2423104.814-2737793.75148-2265.583131.6871215.73710.232-298348.374-2754352.193-3052700.5681E-1438629.862-7696895.378-9135525.240

△ip=AS/EhXEMp/I=6.39X10-8x(-1438629.862)=-9192.84X10-5△2p=△S/EhXEMP0y/I=6.39X10-8X(-7696895.378)=-49183.16X10-5計(jì)算精度校核△Sp=△1p+△2p△sp=△S/EhXEMp0(1+y)/l因止匕△sp=6.39X10-8X(-9135525.240)=-58376.006X10-5△1p+△2p=-(9192.84+49183.16)X10-6=-58376.000X10-5閉合差0.000。4.4.3—位移一一單位彈性抗力及相應(yīng)的摩擦力引起的位移1)各接縫處的抗力強(qiáng)度按假定拱部彈性抗力的上零點(diǎn)位于與垂直軸接近45。的第3截面,a3=44.28 =8b；最大抗力位于第5截面,85=76.25 =ah；拱部各截面抗力強(qiáng)度，按鐮刀形分布，最大抗力值以上各截面抗力強(qiáng)度按下式計(jì)算：22225=o/t(cosab-coSa)/(cosab-coS&)計(jì)算得，53=0 54=0.5436 CT5=5h邊墻截面彈性抗力計(jì)算公會(huì)為：5=5h[1-(yi/yh)2]。

式中y「一一所求抗力截面與外輪廓線交點(diǎn)到最大截面抗力截面的垂直距離；yh 墻底外邊緣c’到最大抗力截面的垂直距離。（y「和yh’在圖3中可量得）y=1.634m; y=3.198m; y=4.776m;則有：06=Ah[1-(1.634/4.776)2]=0.8777怖07=Oh[1-(3.198/4.776)2]=0.5516o0=0；按比例將所求得的抗力繪在圖4上圖4結(jié)構(gòu)抗力圖2）各楔塊上抗力集中力R,按下式近似計(jì)算:RiiiSi外/2式中，Si外一一楔塊i外緣長(zhǎng)度，由圖3量得。尺的方向垂直于襯砌外緣，并通過楔塊上抗力圖形的形心3）抗力集中力與摩擦力之合力R按近似計(jì)算：RiRi',1 2式中P--圍巖與襯砌間的摩擦系數(shù)。取P=0.2,則 RiRi1 2=1.0198R其作用方向與抗力集中力的夾角為B=arctan（j=11.301°。由于摩擦阻力的方向與襯砌位移方向相反，其方向朝上。 R的作用點(diǎn)即為R,與襯砌外緣的交點(diǎn)。將R的方向線延長(zhǎng)，使之交于豎直軸。量取夾角書k（自豎直軸反時(shí)針方向量度）。將R分解為水平與豎向兩個(gè)分力：Rh=Risinipk Rv=Ricos?k以上計(jì)算例入表4-5中，并參見圖3。表4-5彈性抗力及摩擦力計(jì)算表截o(Ohl)(Oi-1+Oi)/2△S外(o)R5)?ksin?kCOS?k30.00000.0000.00000.00000.0000.0001.00040.54360.2721.64750.456762.3700.8860.46451.00000.7721.64751.296776.9160.9740.22660.87770.9391.64751.577489.4141.0000.01070.55160.7151.64751.2007103.7990.971-0.23980.00000.2761.64750.4634116.1260.898-0.440

續(xù)表4-5RH(bh)Rv(Oh)vhRi(Oh)0.0000.0000.0000.4050.2120.2120.4050.4481.2630.2940.5051.6681.2721.5770.0160.5213.2451.5471.166-0.2860.2354.4111.1770.416-0.2040.0314.8270.4544）計(jì)算單位抗力圖及其相應(yīng)的摩擦力在基本結(jié)構(gòu)中產(chǎn)生的內(nèi)力彎矩No siniRv cosiRh軸力 i式中％—-力Ri至接縫中心點(diǎn)K的力臂，由圖3量得，計(jì)算見表4-6和表4-7表4-6M*計(jì)算表截面R4=0.4567OhR5=1.29674OhRs=1.5774OhR7=1.2007oR8=0.4634OhM0OOh)r4i-R4「4ir5i-民r5ir6i-R6r6ir?i-R7r7irsi-R8r8i40.9000-0.411-0.41152.5557-1.1670.9894-1.283-2.45064.0766-1.8622.5820-3.3481.0605-1.673-6.88375.4556-2.4924.1180-5.3402.6538-4.1860.8364-1.004-13.02286.6259-3.0265.5229-7.1624.1930-6.6142.4307-2.9180.8712-0.404-20.124表4-7N「計(jì)算表截面號(hào)asinaCOSa2Rv(ah)!RH(ah)sinaEV(ah)COSaRH(o-h)No0o-h)459.04000.85730.51490.21180.40460.18150.2083-0.0268573.57200.95900.28340.50531.66760.48460.47270.0119686.20900.99780.06690.52153.24490.52030.21700.3033798.84600.9882-0.15290.23514.41100.2323-0.67450.90688111.48300.9309-0.36530.03104.82700.0289-1.76331.79225）單位抗力及相應(yīng)摩擦力產(chǎn)生的載位移 計(jì)算過程見表4-8。面號(hào)Ma0(ah)1/Iy/I(1+y)Ma01/I(ah)Ma0y/I(ah)Ma0(1+y)/I(ah)積分系數(shù)1/34-0.411131.6872396.6424.012-54.127-163.032-217.15925-2.450131.6872596.6755.531-322.653-1461.941-1784.59446-6.883131.6872804.2147.107-906.387-5535.307-6441.69227-13.022131.68721013.9928.700-1714.805-13204.005-14918.80648-20.124131.68721215.73710.232-2650.074-24465.491-27115.5571工-4240.312-31508.650-35748.952表4-8單位抗力及相應(yīng)摩擦力產(chǎn)生的載位移計(jì)算表△i尸/XS/EhXEM,1/1=6.39X10-8X(-4240.312)=-270.960X10-6△2尸^S/EhXEM4/1=6.39X10-8X(-31508.650)=-2013.403X10-6校核為：△儕+△2尸-(270.960+2013.403)X10-6=-2284.363X10-6△SFAS/EhXEM」(1+y)/l=6.39X10-8X(-35748.952)=-2284.358X10-6閉合差0。4.4.4墻底(彈性地基上的剛性梁)位移1)單位彎矩作用下的轉(zhuǎn)角：念=1/(KI8)=131.6872/0.18X106=731.596X10-62)主動(dòng)荷載作用下的轉(zhuǎn)角：%=?TM8P=731.596X(-2265.583)X10-6=-1657491.46X10-63)單位抗力及相應(yīng)摩擦力作用下的轉(zhuǎn)角：B尸BM8「=731.596X10-6X(-20.124)=-14722.64X10-6解力法方程襯砌矢高 f=y8=9.232m計(jì)算力法方程的系數(shù)：an=&1+價(jià)=(67.32+731.596)X10-6=798.913X10-6a12=%+fB=(240.74+9.232X731.596)X10-6=6994.83X10-6a22=522+f2P1=(1433.43+9.2322X731.596)X10-6=63787.228X10-6aio=Aip+Bp+(△1ff+BJXch=-(91928.4+1657491.46+270.960?+14722.64麗)X10-6=-(1749419.86+14993.6 ?)X10-6a20=△2p+fB+(△2ff+fBff)XAh=-(491831.6+9.232X1657491.46+2013.403ffh+9.232X14722.64ffh)=-(15793792.76+137932.82葉)X10-6以上將單位抗力圖及相應(yīng)摩擦力產(chǎn)生的位移乘以 ffh倍，即被動(dòng)荷載的載位移求解方程:

Xi二(a12a20-a22a10)/(a11a22-a12)二(548.873-4.140Ch)其中:Xg=548.873,X其中:Xg=548.873,Xi尸-4.1402X2二(a12a10-a11a20)/(a11a22-a12)二(187.412+2.616c)其中:X2p其中:X2p=187.412,X2F2.616計(jì)算主動(dòng)荷載和被動(dòng)荷載 （ch=1）分別產(chǎn)生的襯砌內(nèi)力計(jì)算公式為:TOC\o"1-5"\h\zMp X1pyX2P Mop\o"CurrentDocument"NpX2p cos Nop和MX1 yX2 MoNX2cosNo計(jì)算過程列入表4-9和表4-10中。表4-9主、被動(dòng)荷載作用下襯砌彎矩計(jì)算表截面MoPX1pyX2p*y[Mp]MOc((Th)X1<T(Th)X2T*y(ch)[Moc](T00.000548.8730.0000.000548.8730.000-4.1400.000-4.1401-127.640548.8730.19937.295458.5280.000-4.1400.521-3.6202-481.033548.8730.806151.054218.8940.000-4.1402.108-2.0323-981.512548.8731.756329.095-103.5430.000-4.1404.5940.4544-1516.611548.8733.012564.485-403.253-0.411-4.1407.8793.3285-1986.864548.8734.531849.164-588.827-2.450-4.14011.8535.263

6-2285.088548.8736.1071144.525-591.690-6.883-4.14015.9764.9537-2389.669548.8737.7001443.072-397.724-13.022-4.14020.1432.9818-2265.583548.8739.2321730.18813.478-20.124-4.14024.151-0.113表4-10主、被動(dòng)荷載作用下襯砌軸力計(jì)算表截面NopcosaX2pcos?:Np]No&飾)X2QOS?(甘):N言丁(ah)00.0001.000187.412187.4120.0002.6162.616138.4040.967181.228219.6320.0002.5302.5302144.5490.870163.083307.6320.0002.2762.2763293.9680.716134.175428.1430.0001.8731.8734452.6540.51496.412549.066-0.0271.3461.3195585.9420.28353.002638.9440.0120.7400.7526663.8700.06612.391676.2610.3030.1730.4767701.253-0.154-28.820672.4330.907-0.4020.5058742.111-0.366-68.635673.4761.792-0.9580.834計(jì)算最大抗力值首先求出最大抗力方向內(nèi)的位移由式：s5y)MphpEI并考慮接縫5并考慮接縫5的徑向位移與水平方向有定的偏離，因此將其修正如下hps(yhps(ysyJMp.5PE I sin55(y5(y5jAsin計(jì)算過程列入表3-11表4-11最大抗力位移修正計(jì)算表~截號(hào)Mp/IM小yiy5-yiMp/I(Y5-Yi)m川(Y5-Yi)積分系數(shù)1/3072279.549-545.1980.0004.531327498.634-2470.2934160382.314-476.6440.1994.332261576.184-2064.8212228825.600-267.5360.8063.725107375.359-996.57343-13635.33259.7331.7562.775-37838.045165.75824-53103.299438.2903.0121.519-80663.911665.76245-77541.042693.0504.5310.0000.0000.0001工621438.869-5000.847位移值為：渝二6.39X10—8X621438.869X0.9590=3808.184X10-5&尸6.39X10-8X(-5000.847)X0.9590=-30.645X10-5則可得最大抗力(Th二Shp/(1/K-U=3808.184X10-5/[1/(0.18X106)+30.645X10-5]=122.063.8計(jì)算襯砌總內(nèi)力按下式進(jìn)行計(jì)算：M=Mp+?MaN=Np+AhN(t計(jì)算過程列入表4-12表4-12襯砌總內(nèi)力計(jì)算表

截面號(hào)MpM[M]m/iMy/INpn[N]e積分系1/30548.873-505.34143.5325732.6590.000187.412319.309506.7210.085911458.528-441.79816.7302203.156438.428219.632308.772528.4040.031742218.894-247.978-29.083-3829.874-3086.879307.632277.857585.490-0.049723-103.54355.366-48.177-6344.348-11140.678428.143228.605656.748-0.073444-403.253406.2482.994394.3181187.686549.066160.998710.0650.004225-588.827642.38353.5567052.62331955.447638.94491.761730.7060.073346-591.690604.55512.8651694.14610346.153676.26158.130734.3910.017527-397.724363.897-33.827-4454.588-34300.335672.43361.583734.016-0.04614813.4776-13.816-0.3389-44.6231-411.961673.476101.820775.296-0.000413881.0635900.60根據(jù)拱頂切開點(diǎn)之相對(duì)轉(zhuǎn)角和相對(duì)水平位移應(yīng)為零的條件來檢查sMEI式中：—M=6.39X10-8X3881.06=24.80X10-5EIa=M8Bi=-0.3389