膨胀土边坡加筋作用的对比模型试验.pdf

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1、第27卷第7期中国公路学报VoI．27NO．72014年7月ChinaJournalofHighwayandTransportJuly2014文章编号：1001—7372(2014)07—0024—08膨胀土边坡加筋作用的对比模型试验肖杰，杨和平，符浩，唐成远(长沙理工大学交通运输工程学院，湖南长沙410004)摘要：为获得大气干湿循环条件下土工格栅加筋柔性支护治理膨胀土边坡坍滑的工作机理，用南宁外环膨胀土制作了一侧加筋一侧素土的室外大型边坡模型，分别埋设体积含水率探头、水平与竖向土压力盒、柔性位移计等测试元件，实施人工降雨模拟干湿循环并跟踪监测两侧坡体的含水率、土压力变化及不同部位格栅的应变

2、变化。结果表明：加筋侧土体的相对平衡含水率及其波动范围均比未加筋侧小；加筋侧的水平与竖向土压力比明显小于未加筋侧；各层格栅越靠近坡面，其应变变化越快，峰值出现越早，沿水平深度呈“凸”形分布，但远小于其允许应变值；验证了膨胀土堑坡柔性支护的“框箍”作用机理。关键词：道路工程；膨胀土边坡；模型试验；土工格栅加筋；干湿循环中图分类号：U416．14文献标志码：AComparisonModelTestonEffectofGeogridReinforcementforExpansiveSoilSlopeXIAOJie，YANGHe—ping，FUHao，TANGXian—yuan(SchoolofTra

3、fficandTransportationEngineering，ChangshaUniversityofScience&Technology，Changsha410004，Hunan，China)Abstract：Inordertounderstandthemechanismofgeogridreinforcementflexiblesupportfortreatmentofexpansivesoilslopeslidingundertheconditionofdry—wetcycles，outdoorlarge—scaleslopemodelsreinforcedandunreinforc

4、edbygeogridweremadewithexpansivesoilfromNanningOuterRingexpressway．Volumetricmoistureprobes，horizontalandverticalearthpressurescellsandflexibledisplacementmeterswereburiedinthemodels．Artificialrainfallwasusedtosimulatethedry—wetcycles．Thechangesinwatercontents，verticalandhorizontalearthpressuresofbo

5、thslopesandthestrainsofdifferentlocationsofgeogridweremonitored．Theresultsshowthattherelativeequilibriumwatercontentanditsfluctuationrangeofreinforcedslopeareall1essthanthoseofunreinforcedslope．Thehorizontalandvertica1earthpressureratioofreinforcedslopeissignificantlessthanthatofunreinforcedslope．Th

6、egeogridstrainchangesfasteranditspeakoccursearlierwithgeogridclosertoslopesurface．Thevariationingeogridstrainisinconvexalongthehorizontaldirection，butallthestrainsarefarlessthanmaximumallowablestrain．Therefore，theframehoopmechanismofgeogridreinforcementflexiblesupportfortreatmentofexpansivesoilslope

7、isverified．Keywords：roadengineering；expansivesoilslope；modeltest；geogridreinforcement；wet-drycycle收稿日期：2013-10—12基金项目：国家自然科学基金项目(50978035，51108049)；交通运输部西部交通建设科技项目(2009353311060)；道路灾变防治及交通安全教育部工程研究中心开