陡倾层状岩质边坡动力响应大型振动台模型试验研究.pdf

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1、JournalofEngineeringGeology工程地质学报1004—9665／2012／20(2)．0242．07陡倾层状岩质边坡动力响应大型振动台模型试验研究术李振生巨能攀侯伟龙李果(成都理工大学地质灾害防治与地质环境保护国家重点实验室成都610059)摘要结合5·12汶川地震诱发的大量次生地质灾害，设计并完成了比例为1：100的边坡大型振动台模型试验，讨论了相似关系和模型的设计、传感器的布置、模型的建造过程，编制了动荷载加载制度。试验结果表明，边坡对输入动荷载具有放大作用，沿坡面向上

2、，PGA放大系数呈上升趋势，并具有一定的节律性，其节律性变化规律受坡体岩性、结构面组合和动荷载振动方向的影响；动荷载x向振动时的坡面峰值重力加速度(PGA)放大系数明显大于z向振动时的坡面PGA放大系数，说明坡体在向振动时的动力响应更为强烈；坡体内PGA放大系数在铅直向上呈线性放大，在水平向上表现为节律性变化。试验结果有助于了解陡倾层状岩质边坡在不同动荷载作用下的响应规律，对研究其变形失稳机制和抗震结构设计提供了依据。关键词岩质边坡动力响应规律振动台模型试验PGA放大系数中图分类号：P642．2

3、2文献标识码：ALARGE．SCALESHAKINGTABLEMoDELTESTSFoRDYNAMICRE．SPoNSEoFSTEEPSTRATIFIEDRoCKSLoPESLIZhenshengJUNengpanHOUWeilongLIGuo(SateKeyLaboratoryofGeohazardPreventionandGeoenvironmentProtectionChengduUniversityofTechnology，Chengdu610059)AbstractThispaperi

4、sbasedonalargenumberofsecondarygeologicaldisastersinducedbytheWenchuanEarthquake．Itdesignsandcompletesalarge—scaleshakingtablemodeltestofslopeswiththescaleof1：100．Itdiscussesthedesignofsimilarityrelationandthemodel，sensorlayout，processofmodelconstruc

5、tionaswellastheseismicwaveloadingsystem．Theresultsshowthatthemodelslopeshaveamplificationeffecttotheinputdynamicload．Upwardalongwiththeslopesurfaces，thePGAamplificationcoefficientshavearisetendencyandsomerhythmic．Thevariationlawofrhythmicisaffectedby

6、thelithologyofslopes，combinationofstructuralsurfaceandvibrationdirectionofthedynamicloads．CoeficientsofthePGAamplificationalongsurfaceofslopesaresignifi—cantlygreaterforthevibrationdirectionofdynamicloadtohorizontal()thanforthedirectionofdynamicloadt

7、overtical(Z)，whichshowsthatthedynamicresponseofslopesisstrongerwhenthevibrationdirectionX．ThePGAamplificationcoefficientsintheverticaldirectionoftheslopebodyareamplifiedlinearly．Theyinthehorizontaldi—rectionchangeinrhythm．Theresultscanhelptounderstan

8、dthedynamicresponserulesofsteepstratifiedrockslopesintheeffectofdifferentkindsofdynamicloads，andprovideabasistostudythemechanismofdeformationandinstabilityofslopesunderearthquakeandthedesignofanti—earthquakestructure．KeywordsRockslope，Dynamicresponse