简介：Thestabilityofriverbankssubjecttoseepageisstudiedexperimentallyandtheoreticallyinthispaper.Byincludingseepageina3-dimensionaltheoreticalanalysis,thestudyfirstshowshowthecriticalslopeorangleofreposeofacohesionlessmaterialisrelatedtotheratioofthehydraulicgradientofseepagetoitscriticalvalueunderthefluidizationcondition.Thecriticalstableslopeisshowntoberelatedtonotonlythehydraulicgradientbutalsotheseepagedirection.Measuredlaboratorydatareasonablyfitwellwiththetheoreticalrelationshipforthecaseofinjectionandsuction.Thedatarevealthattheslopeisreducedwithinjectionandincreasedwithsuction,respectively.Additionally,thestudyidentifiestheseepagedirectionwhichresultsinaminimumcriticalstableslopeforacertainhydraulicgradientofseepage.

简介：柏油的具体核心(ACC)水坝广泛地在中国被造。许多ACC水坝执行井，而是其它在此处学习的西方的中国包括盒子经历了重要的漏。浸透不饱和的水流动的一个数字模特儿被适应通过水坝模仿渗出物。由在不同条件下面比较正常、反常的渗出物地，为实际反常渗出物地的主要原因被识别并且在转变地区(TZ)和下游的水坝壳在ACC和非计划中的、低渗透层(LPL)归因于一个缺点。这些结论与水坝的状况和表演一致。不适当的ACC构造过程可能在ACC引起了缺点。ACC厚度的一个突然的变化可能导致了压力集中并且引起了ACC失败。为TZ和水坝壳的材料来源从说明，和土壤阶段复杂、变化因为TZ不充分地被控制。特别地，测试证明渗透在水坝的这二部分在大范围上变化。意外LPL可能在两个区域存在，并且连续地延长。

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简介：Themovementofwaterflowinunsaturatedfracturedrockwasinvestigatedwiththesandstonesamplethroughexperimentalresearchandnumericalsimulation.Theexperimentalresultsshowthatthearrivingtimeofwettingfrontisdelayedbythefracture,resultingintheincreaseofwatersaturationinthedomainontheupstreamsideofthefracture,whichwilllocallyenhancewaterflowthroughthematrix.Thenumericalsimulationwiththefinitevolumemethodcaptureseffectivelythesecharacteristics.Thecomparisonbetweensimulatedandobservedtraveltimeandarrivingtimeofwettingfrontshowsthattheirdifferenceareverysmallandthesimulatedresultsareinagreementwiththeobservedresults,whichimpliescalibratedparametersarereliableandeffective.Thenaccordingtothecalibratedparameters,fracturedmodelswereestablishedtoexaminehowthechangeoflargefracturedaperturewouldaffectthearrivingtimeofwettingfronts,pressureheadsandwatersaturationontheupstreamanddownstreamsidesoffracture.

简介：AlthoughrainfallisrareontheLoessPlateauofwesternChina,landslidesoccurfrequentlythereinrainyseason.Surveysreportthatlandslidehazardsalwaysfollowheavyrains.Inthisstudy,aseepage-stresscouplingmodelforrainfallinducedlandslideisusedtoexamineanactualdisastrouseventinYulinbytheendofJuly,2017.Theeffectsofrainfallduration,rainfallintensityandsoilweakeningonslopestabilityarestudiedindetail.Theresultsillustratethatthesafetyfactordropssharplyatfirstandthenisgraduallydecliningtobelow1.05duringadditionaltwodaysofheavyrain.Withsoilstrengthsofteningconsidered,theslopewouldbemoreunstable,inwhichtheweakeninginsoilcohesionisfoundtobeamoresensitivefactor.

简介：在华南海把水泡羽毛的出现特征用作一本参考书，这份报纸继续学习水泡羽毛在冷渗出物生产的地震回答活跃区域。使羽毛建模计划更合理，我们修改了原来的建模计划并且重建一个羽毛水身体模型基于它是的半径的变化，水泡在海水升起。羽毛射击集合的地震记录被前面的模拟获得。单个射击的地震记录显示出一个散布波浪领域的明显的特征和模型的周期的特征。射击集合的地震记录用prestack深度移植被处理。它的成像节的边界有好集中效果。迁居节能与更高的精确性清楚地被想象。上述的研究再次为羽毛生产的地震回答的进一步的学习打了一个基础。他们逐渐地也探查了为羽毛处理方法的一个更合适的地震数据并且为羽毛的鉴定提供了理论指导。

简介：在这个工作，试验性的调查被追求了分析影响向下在在在冲积隧道的圆形的桥码头附近的旋涡结构的流动和相应变化的狂暴的特征上的渗出物。实验为没有渗出物，10%渗出物和20%渗出物盒子与不同尺寸的圆形的墩在沙床隧道被进行。象速度和雷纳兹压力那样的狂暴的流动统计的测量被发现在scour洞在以内否定墩在上游而申请向下，渗出物延迟在速度和雷纳兹引起减少的流动的颠倒强调。更高级的雷纳兹砍因为生产，应力在下游的方面占优势弄醒旋涡。到彻底的雷纳兹的所有爆炸事件的贡献砍压力生产被观察了增加与向下渗出物。不可分的规模的分析建议旋涡的那种尺寸与渗出物增加，它为粒子活动性的增加负责。开始搜索评价是消退逐渐地象与一样与膨胀预定的更多增加了向下渗出物。存在向下，渗出物向墩的下游的方面减少旋涡和移动的深度和长度。

简介：Three-dimensionalnumericalmanifoldmethodforunconfinedseepageanalysisisproposedinthisarticle.Byconstructinghydraulicpotentialfunctionsofthemanifoldelement,theelementconductivitymatrixandtheglobalsimultaneousequationsforunconfinedseepageanalysisarederivedindetail.Thealgorithmoflocatingthefreesurfaceandtheformulaforseepageforcesarealsogiven.Three-dimensionalmanifoldmethodemploysthetetrahedralmathematicalmeshestocoverthewholematerialvolume.Intheiterativeprocessforlocatingthefreesurface,themanifoldmethodcanachieveanaccurateseepageanalysisofthesaturateddomainbelowthefreesurfacewithmathematicalmeshesunchanged.Sincetheshapeofmanifoldelementscanbearbitrary,thedisadvantageofchangingthepermeabilityoftransitionalelementscutbythefreesurfaceintheconventionalFiniteElementMethod(FEM)isremoved,andtheaccuracyoflocatingthefreesurfacecanbeensured.Furthermore,theseepageforceactingonthetransitionalelementscanbeaccuratelycalculatedbythesimplexintegration.Numericalresultsforatypicalexampledemonstratethevalidityoftheproposedmethod.

简介：连贯的沉积巩固在压力领域和水坝和水库的渗出物地里引起显著变化，由于在沉积的干燥密度的变化。这研究分析了连贯的沉积，和巩固机制的物理化学的特征在巩固的起始的阶段期间为密度开发一个动态模型和地位公式。斜槽实验然后用连贯、非连贯的沉积样品被进行由把计算价值比作测量沉积压力验证导出的公式。另外，从一个水坝基础的渗出物上的沉积巩固的效果用ABAQUS软件被调查。这案例研究证明沉积的干燥密度在巩固(约65%全部的生长)的起始的阶段期间戏剧性地增加了，但是它在长过程的以后的阶段慢慢地增加了。在上游的反渗出物墙的水头实质地在水坝后面由于自然毛毯被削弱。

简介：FordeepfoundationpitdewateringintheYangtzeRiverDelta,itiseasytomakeadramaticdecreaseoftheundergroundwaterlevelsurroundingthedewateringareaandcauselandsubsidenceandgeologicdisasters.Inthiswork,athree-dimensionalfiniteelementsimulationmethodwasappliedintheforthsubwayofDongjiadutunnelrepairfoundationpitdewateringinShanghai.Inordertocontrolthedecreaseoftheundergroundwaterlevelaroundthefoundationpit,thefoundationpitdewateringmethodwasusedtodesigntheoptimizationprojectofdewatering,whichwassimulatedundertheseconditionsthattheaquifersdepositedlayerbylayer,thebottomoftheaquiferswentdeepto144.45m,theretainingwalloffoundationpitshieldwentdeepto65m,thefiltersoftheextractionwellswerelocatedbetween44mto59m,thewaterlevelinthedeepfoundationpitwasdecreasedby34m,andthemaximumdecreaseofwaterleveloutsidethefoundationpitwas3m.Itisshownthattheoptimizationprojectandthepracticalcaseareconsistentwitheachother.Accordingly,thethree-dimensionalfiniteelementnumericalsimulationisthebasictheoryofoptimizationdesignofengineeringstructuresofdewateringindeepfoundationpitinsuchareas.

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简介：Theinitiationofpipelinespanninginvolvesthecouplingbetweentheflowoverthepipelineandtheseepage-flowinthesoilunderneaththepipeline.Thepipelinespanninginitiationisexperimentallyobservedanddiscussedinthisarticle.Itisqualitativelyindicatedthatthepressure-dropinducedsoilseepagefailureisthepredominantcauseforpipelinespanninginitiation.Aflow-pipe-seepagesequentialcouplingFiniteElementMethod(FEM)modelisproposedtosimulatethecouplingbetweenthewaterflow-fieldandthesoilseepage-field.Acriticalhydraulicgradientisobtainedforobliqueseepagefailureofthesandinthedirectiontangenttothepipe.Parametricstudyisperformedtoinvestigatetheeffectsofinflowvelocity,pipeembedmentonthepressure-drop,andtheeffectsofsoilinternalfrictionangleandpipeembedment-to-diameterratioonthecriticalflowvelocityforpipelinespanninginitiation.Itisindicatedthatthedimensionlesscriticalflowvelocitychangesapproximatelylinearlywiththesoilinternalfrictionangleforthesubmarinepipelinepartially-embeddedinasandyseabed.

简介：Three-dimensionalseepageindoublefracturedmediawasmodeledinthispaper.Thedeterminationofhydraulicconductivitytensorofrockmassisavitalproblemfortheseawaterintrusionorseawaterencroachmentandseepageoffissuredmedium.Accordingtothegeologicalandhydrogeologicalconditionsforthe2nd-stageconstructionoftheThreeGorgesProject(TGP),thephysicalandmathematicalmodelsforthegroundwatermovementthroughthe3Ddoublefracturedmediaofrockmassduringconstructionwereestablishedinthispaper.Basedondiscontinuity-controlinversetheory,somerelatedparametersofdoublefracturedmediawereinversedwithfluxbeingtheknownquantityandcalibrationofwatertabletheobjectivefunction.Synchronously,theseepagefieldoftheconstructionregionwassystematicallyanalyzedandsimulated,theresultsofwhichexhibitthatthedoublefracturedmediamodeloffracturewatercancomprehensivelyandcorrectlydescribethegeologicalandhydrogeologicalconditionsintheconstructionregion.

简介：LabexperimentandmathematicalsimulationModularthreedimensionalfinitedifferencegroundwater(MODFLOW)wereperformedinasoiltanktosimulatethehydrogeochemicalinteractionbetweenlakeandtypicalunconfinedaquifer.Resultsshowthatthevelocitydecreasesexponentiallywiththetransectdistanceonseepageface.Themaximalvelocityoccursatthetoppointofseepageface.Theobliquityofseepagefacehasagreatinfluenceonthemaximumanddistributionofseepagevelocity.Withtheincreaseoftheobliquityofseepageface,themaximalvelocitydecreasesquicklyandthevelocitydistributionbecomesmuchmoreeven.Mostofgroundwaterflowandpollutantfluxdischargesthroughanarrowportionnearthetopofseepageface.Theflowandmassconcentratedinthenarrowportionincreasewiththedecreaseoftheobliquityofseepageface.Thesewillbenefittodesignareasonableandeconomicalscenariotomanagelakeshoreandtocontrolthepollutionoflakewaternearlakeshore.

简介：Thecut-offnegativepressuremethodisoneofeffectiveapproachestosolvetheseepageflowwithfreesurface.Accordingtothecharacteristicsofthismethod,however,ithasbeenfoundoutthatthedeficiencyofthealgorithmsistoeasilycauseinaccuratesimulationinthevicinityoffreesurfaceowingtothepenaltyfunctionwithonlyonecontrollingpenaltyparameter.Therefore,animprovedcut-offpressuremethodwaspresentedbyconstructingpenaltyfunctionwithtwocontrollingpenaltyparameters.Theimprovedalgorithmswereillustratedtobeabletoimprovethesimulationaccuracyandraisetheconvergencespeedthroughconsideringtheeffectsofthepartiallysaturatedorunsaturatedelementsmorereasonablyandcalculatingthenodalexternalforcesmoreaccurately.Finally,theimprovedcut-offnegativepressuremethodwasappliedtothesimulationofunsteadyseepageflowwithfreesurface,andthecorrespondingprogramcodesweredevelopedwithvalidationofsomecases.

简介：Hydrocarbonmicro-seepagecancauseoxidationreductionreactionsandproducealteredmineralsinsurfacesedimentsandsoil.Thetypicalalteredmineralsmappingbytheirdiagnosticspectralfeaturesonhyper-spectralimagesisanimportanttoolforthepetroleumexplorationindustry.Inthisstudy,theairbornehyper-spectraldatawereusedtoinvestigatethealteredmineralsinducedbyhydrocarbonmicro-seepagesbyspectralfeaturefitting(SFF)intheloesscoverageareaofXifengOilfield.Theresultsrevealthatthedistributionregionofthealteredmineralsinducedbyhydrocarbonmicro-seepageislargerthantheknownoilfieldexplorationarea.Thepotentialhydrocarbonmicro-seepageregionwasalsorevealedbythedistributionofalteredmineralsbesidestheknownhydrocarbonarea.Afastindexwasproposedbytheabsorptiondepthsofclayandcarbonatemineralsforassessmentofhydrocarbonmicroseepage.Anditgavemuchclearerboundariesforthehydrocarbonmicro-seepageintheloesscoverageareathanthosebythealteredmineralmapping.Inaddition,somefieldsampleswereanalyzedbyX-raydiffraction(XRD)andatomicabsorptionspectrophotometertovalidatetheresults.Withintheextentsofhydrocarbonmicro-seepage,therearelowercontentsofferricironandhighercontentsofcarbonatemineralsinthesesamples.Therefore,itissatisfactorytohavetheairbornehyper-spectraldatatooutlinetheextentsofhydrocarbonmicro-seepageforfurtherhydrocarbonexplorationintheloesscoveragearea.

简介：摘要：穿堤管道施工对周边原始土层造成了扰动，加上运行期管道内水压力的作用，容易形成缝隙，产生渗漏通道，影响堤防安全，因此需要对管道出入土点附近进行防渗处理，文章以淮南市毛集实验区城乡供水一体化工程穿越便民沟管道为例，浅析穿堤类管道项目防渗处理措施。

简介：Ascientifichypothesisisproposedandpreliminarilyverifiedinthispaper:underthedrivingofseepageflows,theremightbeaverticalmigrationoffine-grainedsoilparticlesfrominteriortosurfaceofseabed,whichisdefinedas‘sub-bottomsedimentpumpaction’inthispaper.FieldexperimentswereperformedtwiceontheintertidalflatoftheYellowRiverdeltatostudythisprocessviabothtrappingthepumpedmaterialsandrecordingtheporepressuresinthesubstrate.Experimentalresultsarequiteinterestingaswedidobserveyellowslurrywhichismainlycomposedoffine-grainedsoilparticlesappearingontheseabedsurface;seepagegradientswerealsodetectedintheintertidalflat,undertheactionoftidesandsmallwindwaves.Preliminaryconclusionsarethat‘sedimentpump’occurswhenseepageforceexceedsacertainthreshold:firstly,itisbigenoughtodisconnectthesoilparticlesfromthesoilskeleton;secondly,thedegreeofseabedfluidizationorbioturbationisbigenoughtoprovidepreferredpathsforthedetachedmaterialstomigrateupwards.Thentheywouldbefirstlypumpedfrominteriortothesurfaceofseabedandtheneasilyre-suspendedintooverlyingwatercolumn.Influentialfactorsof‘sedimentpump’aredeterminedashydrodynamics(waveenergy),degreeofconsolidation,indexofbioturbation(permeability)andcontentoffine-grainedmaterials(sedimentaryage).Thisnewperspectiveof‘sedimentpump’mayprovidesomeimplicationsforthemechanisminterpretationofseveraluncleargeologicalphenomenaintheYellowRiverdeltaarea.

简介：摘要：持续干旱容易造成河道水位偏低，导致堤防迎水侧出现滑坡等险情，文章以枞阳县横埠河新少三大圩钱铺段堤防为例，浅析浅析持续干旱造成堤防险情原因及处理措施。