干湿循环作用下砂岩的劣化及破坏特性研究.pdf

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1、水利水电技术第48卷2017年第5期干湿循环作用下础岩硇劣化及破坏特性研究向力1，王乐华1，陈招军2，李洁1，马云彪1(1．三峡大学三蛱库区地质灾害教育部重点实验室，湖北宜昌443002；2．中建三局第一建设工程有限责任公司，湖北武汉430074)摘要：针对干湿循环作用下消落带砂岩岩体强度衰减易导致砂岩边坡失稳的问题，以三峡库区秭归县沙镇溪典型库岸边坡砂岩试样为研究对象，采用浸泡一烘干处理方式模拟岩石干湿循环过程，将试样分组进行单轴压缩试验和直接剪切试验研究，并通过数值模拟，从变形的角度分析破坏过程。结果表明：千湿循环对砂岩的

2、劣化作用在初期表现强烈，随着循环次数增加，作用逐渐减弱；在相同循环条件下，砂岩的极限抗剪强度随法向应力的增大而增加，相同法向应力作用下砂岩极限抗剪强度随干湿循环次数的增加而减小；粘聚力和内摩擦角随着干湿循环次数的增加而逐渐减小，总劣化度逐渐增大。试验结果对水库砂岩边坡稳定性分析具有较强的参考价值。关键词：干湿循环；单轴压缩试验；直接剪切试验；数值模拟doi：10．13928／j．cnki．眦he．2017．05．022中图分类号：Tv223．1文献标识码：A文章编号：1000一0860(2017)05一0142．06Stlld

3、yondeteriorati蛐andfanurecharacteristicsof鼢ndstone蛐deremctofwet—drycycleXIANGLil，WANGLehual，CHENZhaojun2，LIJiel，MAYunbia01(1．KeyktbomtoryofGeolo舀calHazardson’nIreeGo唱esReseⅣojrAreaofMinistryofEducation，ChinaThreeGorgesUnjvlersity，Yichang443002，Hubei，China；2．ChinaCons

4、tmction111irdBureauFirstEngineeringCo．，Ltd．，Wuh粕430074，Hubei，China)Abstract：Aimingattheproblemf而mthestren昏hreductionofsandstonemassatwater-level-nuctuationzonetllati8pronetocausetheinstabilit)rofsandstoneslope，thewet-drycyclepmcessofthemckissimulatedwi山tlletreatment

5、modeofsoakir培飘ddryingbytakingthesandstonesamplestakenfbmtIletypicalreservoirbankslopeatSh北henxiTownofZiguiCountywithintheareaoftIleThree(b唱esReservoirasthestudyobjective，forwhichtlleuniaxialcompressiontestandtIledirectsheartesta肥madeonthes锄plesingmups，andthenthefajl

6、ureprocessisanalyzedfbmtheaspectofdeformationtllroughtllerelevantnu—mericalsimlllation．Theresultshowsthattheef玷ctfromthewet-drycycleontlledeterioration0fthesandstoneappearsstmndyatt}leinitia工periodofthecyckaIldthenisgraduallyreducedalongw油theincreaseofthenuIl【lberof

7、tllecycle．Underthes绷ecyclicconditions，theultimateshearstren昏hofthesandstoneisincreasedalongwiththeincreaseoftheno珈alstress，whileitisdecreasedalongwiththeincreaseof也ewet—drycydesunder出esameeff’ec￡softheno硼alstress．Moreover。tllecohesionandimemal衔ctionan—earegraduallyd

8、ecreaseda10ng诵ththeincreaseofthenumberofwet-drycycle．Meanwhile，thetotaldegreeofdeteIiorationisincreasedgraduallyaswell．Thetestresuhhasabet