人类活动对大坝的影响

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1、EFFECTOFROCKMASSESSURROUNDINGCONCRETEDAMSONTHEIRBEHAVIORV.N.DurchevaUDC624.042.7:627.824.7.012.4Itisknownthatthereliableoperationofadamdependsonconsiderationoftheengineering-geologicalcharacteristicsoftherockfoundation.Of86damsinwhichcrackingledtofai

2、lureortheneedforrepairswithemptyingthereservoir,inelasticdeformationsofthefoundationswerethecauseofsuchastatein19ofthem;70%ofthedamswerearch,inwhichtheroleofthesurroundingrockmassesisespeciallysubstantial.Thecauseofinhomogeneityofthestress-strainstat

3、eisusuallyrelatedtoachangeinmechanicalcharacteristicsoftherocks,pipingphenomena,nondesignstressfieldinthefoundation,etc.Whereashydraulicengineeringstudiesrockmassesfromthestandpointofgeomechanics,basicscienceexaminesthetechnogeniceffectofhydrodevelop

4、mentsonlyfromthestandpointofgeneralglobalproblemsofphysicsoftheearthUnfortunately,theresultsoflong-terminvestigationsoflargemovementsoftheca吗ionslopeoftheToktogulhydroelectricstationarenotdemandedbyhydraulicengineers,justasseismicityinducedbytheChirk

5、eyreservoirisnotcorrelatedwiththebehavioroftheconcretedarn[1].Concretedams,beingatechnogenicfactorchangingthenaturalequilibriumofthecanyonandatthesametimebeingrestrainedbythecanyonwalls,begintoreacttoallprocessesoccurringinthesurroundingrocks.Excavat

6、ionofthefoundationpit,blasting,theweightfromthedambeingconstructedandfromthereservoirwater,thehydrostaticloadtransmittedtothecanyonwalls,andthegradientsofthehead-allthesenewforcesdisturbthepreviousequilibriumstateinthehierarchicalstructureofblocksand

7、slabsofrocksandtheiradaptationbeginstothechangingconditionsuntiltheestablishmentofanewequilibriumstatebetweentheconstantseasonallyvaryingforcesandstressstrainstateofthecanyoninthezoneofinfluenceoftheseforces.Irreversiblesettlementsofthefoundationandh

8、orizontalmovementsofthedamcrestandcanyonundertheeffectofloadsfromthedamandreservoirareanoutwardmanifestationofadaptationofthestructure,butthemechanismitselfoftheeffectoftheseforcesondeformationofblocksandslabsinthehierarchicalsystemremainsunknown.The