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《強(qiáng)震條件下碎裂巖體崩塌機(jī)理及崩塌后壁對堆積體穩(wěn)定性影響研究.pdf》由會員上傳分享,免費在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、JournalofEngineeringGeology工程地質(zhì)學(xué)報1004—9665/2011/19(2)一0205—08強(qiáng)震條件下碎裂巖體崩塌機(jī)理及崩塌后壁對堆積體穩(wěn)定性影響研究術(shù)趙偉華黃潤秋趙建軍巨能攀李果(成都理工大學(xué)地質(zhì)災(zāi)害防治與環(huán)境保護(hù)國家重點實驗室成都610059)摘要、“5·12”汶川地震的強(qiáng)震作用誘發(fā)產(chǎn)生了大量崩塌地質(zhì)災(zāi)害,且多發(fā)生于碎裂結(jié)構(gòu)巖體中。崩塌后斜坡后緣巖體及前緣堆積體的穩(wěn)定性和后緣巖體對前緣堆積體穩(wěn)定性的影響研究同樣是震后災(zāi)害所面臨的問題。以干河溝溝口斜坡為例,在分析該斜坡結(jié)構(gòu)特征及崩塌機(jī)理的基礎(chǔ)上,采用二維離散元軟件UDEC模擬了斜坡在天然或強(qiáng)震條
2、件下的穩(wěn)定狀態(tài)和可能失穩(wěn)過程;運用極限平衡法對陡壁巖體再次崩塌,產(chǎn)生新物質(zhì)堆載在現(xiàn)有崩塌堆積體后緣前、后分別建立模型進(jìn)行了穩(wěn)定性分析。研究結(jié)果表明:碎裂巖體崩塌過程可分為應(yīng)力重分布、潛在崩塌體形成和地震誘發(fā)崩塌3個階段。崩塌堆積體在考慮后緣堆載作用之前,在天然或地震環(huán)境下均處于相對穩(wěn)定狀態(tài),考慮堆載作用之后,其可能會在地震條件下失穩(wěn)。離散元法和極限平衡法的組合使用,對于解決同類斜坡的同類問題切實可行。關(guān)鍵詞強(qiáng)震碎裂巖體崩塌后壁堆積體穩(wěn)定性中圖分類號:P642.21文獻(xiàn)標(biāo)識碼:ARoCKFALLMECHANISMoFCATACLASTICRoCKMASSANDINFLU.ENCE
3、oFBACKWALLUPoNTHESTABILITYoFACCUMULATIoNUN.DERSTRoNGEARTHQUAKEZHAOWeihuaHUANGRunqiuZHAOJianjunJUNengpanLIGuo(StateKeyLaboratoryofGeologicalHazardPreventionandGeologicalEnvironmentProtection,ChengduUniversityofTechnology,Cheng—du,Sichuan610059)AbstractTheWenchuan8.0ea~hquaketriggeredahugenumb
4、erofrockfallhazards.Thehazardsmosthappenedincataclasticrockmass.Therespectivestabilityofthebackwallandthefrontaccumulationoftheslopeandthein—fluenceofthebackwalluponthestabilityofaccumulationareproblemsthatarefacedbypeopleaftertheearth—quake.ThispapertakestheGanhekourockfallingaccumulationas
5、aexample.Itisbasedonanalysisofthestruc—turefeatureandgeneticmechanismoftheslope.Itusesthe2DDiscreteElementMethod-UDECtosimulatethestabilitystatusandpossiblefailureprocessoftheslopeundernatureorearthquakecondition.Itusesthelimitequi—libriumtheorybasedmodelsandanalysethestabilityofaccumulation
6、beforeorafterloadedbynewsubstancegener—atedbynewrockfal1.Theresultsshowthatthegeneticprocessofrockfallingaccumulationcandividedtostressre—distribution,theformationofpotentialrockfallmassandrockfallinducedbyearthquakethreephases.Be~reload—ingfunction,theaccumulationisrelativelystablebothunder
7、natureorearthquakecondition.Butafterconsidering$收稿日期:2010—08—20;收到修改稿日期:2011一O1一l2.第一作者簡介:趙偉華,地質(zhì)工程專業(yè).Email:fhqwfnwxfzhao@qq.conJournalofEngineeringGeology工程地質(zhì)學(xué)報2011thefunctionofloading,itmayfailunderearthquake.Thecombineduseofdiscreteelementmethoda