简介：Basedon3DBiot’sconsolidationtheoryandnonlinearDuncan-Chang’smodel,a3DFEM(finiteelementmethod)programisdevelopedconsideringthecouplingofgroundwaterseepageandsoilskeletondeformationduringexcavation.Thecomparisonbetweentheanalysisresultconsideringthevariationofwaterheaddifferenceandthatwithoutconsideringitshowsthattheporewaterpressuredistributionoftheformerisdistinctlydifferentfromthatofthelatterandthatthefoundationpitde-formationsoftheformerarelargerthanthoseofthelatter,sothattheresultwithoutconsideringthevariationofwaterheaddif-ferenceisunreliable.Thedistributionrulesofsoilhorizontalandverticaldisplacementsaroundthepitandexcessporewaterpressureareanalyzedindetailintimeandspace,whichisverysignificantforguidingundergroundengineeringconstructionandensuringenvironmentsafetyaroundthepit.

简介：Excavatingsandsandgravelonlandincombinationwithconstructingreservoirsforstoringfreshwaterisanidealapproachinatolls.Appropriateminingofgravelfromtheprogradinggravelbeachisacceptable.Diggingreefrockclosetotheedgeofthewideoceanreefflatwithoutsurfaceloosesedimentsonitorsandbeachcanbeaccepted.Excavatingsandfromsomedepthsinlagoonisascientificapproachparticularlyimportantforurbanizedatolls.However,selectingappropriatesitesforminingsandotherthanatsomedepthsinlagoonissuitabletoruralislandswithoutdensepopulations.Thesesitesincludeupdriftsideoflonggroinonthereeffiat,partlyfilledaccesschannel-port,outletofartificialchannelandlagoonmarginontheprogradingcoast.

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简介：摘 要：莫高窟石窟艺术是第4世纪到第14世纪我国劳动人民的艺术结晶，其中建筑、塑像、壁画等造型艺术形式在石窟的开凿与建造中颇有体现，因此探究莫高窟石窟的成型方式对于敦煌学的研究内容具有很强指导意义。

简介：EngineeringexcavationGIS(E2GIS)isareal-3DGISservingforgeosciencesrelatedtogeo-engineering,civilengineeringandminingengineeringbasedongeneralizedtri-prism(GTP)model.AstwoinstancesofGTPmodel,G-GTPisusedforthereal-3Dmodelingofsubsurfacegeologicalbodies,andE-GTPisusedforthereal-3Dmodelingofsubsurfaceengineeringexcavations.InthelightofthediscussionsonthefeaturesandfunctionsofE2GIS,themodelingprinciplesofG-GTPandE-GTPareintroduced.Thetwomodelscoupletogetherseamlesslytoformanintegralmodelforsubsurfacespatialobjectsincludingbothgeologicalbodiesandexcavations.Anobject-orientedintegralreal-3Ddatamodelandintegralspatialtopologicalrelationsarediscussed.

简介：作为爆炸的最批评的公共危险，地面颤动从社区收到了许多注意。压制颤动的确定的国家标准在结构上影响的许多国家，而是人的安全上的一个接受世界的爆炸颤动标准仍然失踪。以便从爆炸评估人的反应到颤动在中国的一个大规模岩石斜坡的挖掘，这研究试图建议一个修订标准。颤动频率被介绍改进存在单个因素(山峰粒子速度)标准由矿(USBM)的美国局推荐了。新标准的可行性基于领域颤动监视和人的反应的调查被检查。而且，人上的空气过压或强风效果也被讨论了。结果显示影响的全部地区能被划分成三subzones：严重烦恼，轻烦恼并且感觉地区根据修订安全标准。建筑公司和本地居民在这个影响度评价以后提供了积极评价，它显示介绍标准对评估人的反应到附近的强风合适。不过，在它能是以前，这个特定的标准需要更多的领域测试和确认

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简介：Evidenceforamantleand/orbasalticcomponentinKTboundarydistalejectaisapparentlyinconsistentwithejectionfromChicxulubCratersinceitislocatedon~35kmthickcontinentalcrust(DePaoloetal.,1983;Montanarietal.,1983;HildebrandandBoynton,1988,1990).Evidenceformafic/ultramafictargetrockswasreinforcedbydiscoveryofchromites,somewithshockplanardeformationfeatures(PDF),inimpactlayersamplesfromsitesinsouthernColoradoandeasternWyoming(Bohoretal.,1990).However,untilnowitwasunclearwhetherthechromitesoriginatedwithanimpactororwithterrestrialtargetrocks.Tothisend,high-precision54Cr/52CrisotoperatiosweremeasuredonKTboundarychromitesalongwithknownterrestrialchromites.Wefindaterrestrial54Cr/52CrratioinKTboundarychromitesfromimpactlayersamplescollectedattheabovesitesoverthelastseveralyears(Fig.1).Ejectedterrestrialchromitessuggesttheimpactsampledterrestrialmaficand/orultramafictargetrocksnotknowntoexistintheChicxulubtargetarea.