南京地铁区间盾构隧道下穿玄武湖公路隧道施工的关键技术研究

2611Vol.26No.11200511RockandSoilMechanicsNov.20052004-05-282004-12-291968E-mail:[e-mail]10007598(2005)11171106610031-6m-TU454AResearchonkeytechniqueofshieldtunnelconstructionbeneathadjacentexistinghighwaytunnelZHANGZhi-qiang,HEChuan(SchoolofCivilEngineering,SouthwestJiaotongUniversity,Chengdu610031,China)Abstract:Themechanicalbehaviourofshieldtunnelconstructionbeneathadjacentexistinghighwaytunnelisstudiedbyusingthree-dimensionalfiniteelementnumericalsimulationmethod.Theresearchdemonstratesthatitisdangeroustoincreasejackforcesoftheshieldmachineacrossadjacentupperexistinghighwaytunnelwhichisconsideredasakindofunloadingstructure.Inaddition,thejackforcesoftheshieldmachineisneededtobedropdowntothelimitvalueat6mdistancefromtheedgeofupperexistinghighwaytunnelandthemeasurementoftheexistinghighwaytunnelfloorisenhancedinadvancementprocessofshieldmachinetoguaranteethesafetyofupperexistingstructure.Keywords:shieldtunnelconstruction;adjacentexistingupperstructure;three-dimensionalfiniteelement1[1]k12+317.948+294.378k12+317.266+294.69613m6.8m1.317m2.024m1.307m2.014m1.004m1.711m12005[2][3,4](a)(b)1Fig.1TheshieldtunnelconstructionbeneathadjacentexistinghighwaytunnelinNanjingmetro2-TA15[5]III33.13.1.1(2)72m80m30m5m45.6m[6]2(:m)Fig.2FEMsimulationmodel(unit:m)3.1.2TA15Zs-3(X=50549.50mY=29567.20m)51C500.60.8[7]0.75C30C2523.2355m42845.680721.004m1.711m1712111Table1GeotechnicalparametersfornumericalsimulationEGPaνγkN·m-3ckPaϕ()7.110-30.3819.3835.616.031.00.2025.002.75260.5C3029.00.2025.002.39559.3φ600mmC258.540.3819.199.424.34.870.3819.3541.26.90Qal46.390.3819.7549.27.31Qal4Qal37.240.3819.6287.623.56.010-30.3620.450.2536.87Ps1.2MPa0.5MPa35.00.1725.00424162.7C5035cm1.2m4.876.3310.380.3619.3520.4541.20.256.9036.87Qal4ηη=0.753.33.3.14(20%)80%700800t50010001500t3.3.2554ZXY4.1(a)(b)3Fig.3Layoutoftensionpile(a)20%(b)80%(c)500t1000t1500t4Fig.4Differentthrustingforcesatthecuttingfaceduetoshieldmachineadvancement5Fig.5Analysisofshieldtunnelingadjacenttodifferentpositionsofexistingupperhighwaytunnel(1)500t1234517132005(2)(1)50010001500t6327.2m627.2mFig.6Selectiveanalysisrangeofexistingupperhighwaytunnel4.1.12500t2(1)500t30.420mm(7)6m8(2)1∼59(3)891(4)52.045mm2500tTable2Themaximumheavedeformationoccurredindifferentpositionsunder500tthrustingforcemmmm1+0.3986m+1.3301.3m2+0.2196m+1.3001.3m3+0.4206m+1.2941.3m4+0.2886m+1.3071.3m5+0.018+2.0451.3m7500t3:mFig.7Illustratingthemaximumheavedeformationofthirdpositionunder500tthrustingforce(unit:m)8Fig.8Theoccurrencepositionofthemaximumdeformationofhighwaytunnelfloor123459Fig.9Rankofthe5markedpositionsoffloorinsequenceofthemaximumheavedeformation31714114.1.2333Table3Themaximumheavedeformationandtheiroccurredpositionsunderdifferentthrustingforcestmmmm500+0.4206m+1.2941.3m1000+0.8326m+2.5891.3m1500+1.2496m+3.8831.3m3(1)1500t1.249mm(2)50010001500t6m(3)1500t3.883mm4.2-(1)1-10(2)(3)1145(a)1(b)2101Fig.10Illustratinglongitudinalstressdistributionofthefloorwhileshieldmachinejustbegancrossingundertheexistinghighwaytunnel11Fig.11Thedivisiondomainforthemaximumcompressionandtensionstressesdistribution4Table4Themaximumadditionalcompressionandtensionstressalongthehighwaytunnelfloortransverseandlongitudinaldirectionduetoshieldmachineadvancement()()/kPa/kPa/kPa/kPa189.94684.4108201.646212.98583500t130.54759.5126203.910146.479631000t261.093119.0306407.813292.963631500t391.634178.5466611.714439.4466171520055Table5Themaximumadditionalcompressionandtensionstrainalongthehighwaytunnelfloortransverseandlongitudinaldirectionduetoshieldmachineadvancement()()10-510-510-510-510.870-0.73882.270-2.65083500t1.390-0.70762.300-1.710631000t2.770-1.41064.530-3.420631500t4.160-2.12066.800-5.130645(1)(2)(3)6m65(1)-6m-(2)500t0.420mm1500t1.249mm6m(3)1000t1000t0.832mm1000t[1].[R].:,2003.[2].[M].:[s.n.],1996.[3],.[J].,2004,25(2):545546.SHAOHua,ZHANGZi-xin.Analysisofdisturbingeffectonrunningsubwaycausedbyadjacentshield-driven[J].RockandSoilMechanics,2004,25(supp.2):545546.[4],.[J].,200325(1):9295.ZHANGZhi-qiang,HEChuan.Researchonmechanicalbehaviourofashieldtunnelconstructioninmetroadjacenttoexistingpilefoundation[J].JournaloftheChinaRailwaySociety,2003,25(1):9295.[5].[R].:,2001.[6],,,.[J].,1995,16(3):712.ZHENGHong,GEXiu-run,GuXian-rong,etal.SomeproblemsinFEAforgeotechnicalengineering[J].RockandSoilMechanics,1995,16(3):712.[7].[M].:,1997.7981.1716