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《褥墊層厚度對(duì)復(fù)合地基CFG樁土應(yīng)力比影響的試驗(yàn)研究》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、第37卷,第3期公路工程Vo1.37,No.32012年6月HighwayEngineeringJun.,2012褥墊層厚度對(duì)復(fù)合地基CFG樁土應(yīng)力比影響的試驗(yàn)研究徐繼欣,張鴻,周院芳,陳書全,熊茂東。(1.安徽省公路工程檢測(cè)中心,安徽合肥230022;2.南昌工程學(xué)院,江西南昌330099;3.江西公路開發(fā)總公司,江西南昌330038)[摘要】褥墊層厚度設(shè)置是否合理,對(duì)水泥粉煤灰碎石樁(CFG樁)復(fù)合地基的承載與變形特性將產(chǎn)生較大的影響。在江西某高速公路采用CFG樁加固軟土地基試驗(yàn)現(xiàn)場(chǎng),對(duì)不同褥墊層厚度工況
2、下的樁土應(yīng)力比進(jìn)行了現(xiàn)場(chǎng)靜載試驗(yàn)測(cè)試,并模擬各個(gè)工況對(duì)樁土應(yīng)比和土體沉降進(jìn)行了定量數(shù)值計(jì)算,研究結(jié)果表明:數(shù)值計(jì)算結(jié)果與實(shí)測(cè)值較為接近,具有相似的變化規(guī)律,在樁長(zhǎng)和樁間距一定的條件下,樁土應(yīng)力比隨墊層厚度的增加而減小,但褥墊層超過(guò)一定水平,厚度對(duì)樁土應(yīng)力比的影響較小。在路堤荷載作用下,當(dāng)樁間距為1.5m,褥墊層采用中粗砂時(shí),厚度宜為3O一40cm。該研究成果可為該地區(qū)高速公路CFG樁加固軟土地基的設(shè)計(jì)提供參考。[關(guān)鍵詞】高速公路;CFG樁復(fù)合地基;褥墊層厚度;靜載試驗(yàn);數(shù)值模擬;樁土應(yīng)力比[中圖分類號(hào)]U44
3、3.15[文獻(xiàn)標(biāo)識(shí)碼]A[文章編號(hào)]1674—0610(2012)03—0059—04ExperimentalStudyonEffectofCushionThicknesstoPileSoilStressRatioofCFGCompositeFoundationXUJixin,ZHANGHong,ZHOUYuanfang,CHENShuquan,XIONGMaodong(1.AnhuiTestingCenterForHighwayEngineering,Hefei,Anhui230022,China;2.Co
4、llegeofCivilEng.&Architecture,NanchangInstituteofTechnology,Nanchang,Jinagxi330099,China;3.JiangxiHighwayExploitationParentCompany,Nanchang,Jiangxi330038,China)[Abstract]Thedesignofcushionthicknesswillproducebiggereffectonthebearinganddeforma-tionofcementfl
5、yashgravelpile(CFGpile)compositefoundation.Pile-soilstressratioofCFGpilecompositefoundationwasmeasuredundertheconditionoffieldstaticloadtestwithvariablecushionthicknessinoneexpresswayinJiangxiprovince,andquantitativenumericalcalculationforthepilesoftra—tioa
6、ndsettlementofCFGpilecompositefoundationwascarriedout.Theresultsshowthat:thenumericalcalculationresultsandthemeasuredvaluearerelativelyclose,withsimilarchangesinthelaw.Underthecertainpilelengthandpilespacing,thestressratioofpile—soildecreasedwiththeincrease
7、ofcushionthickness.Butwhenthethicknessofcushionisaboveacertainvalue,itinfluencedlessonthestressra—tioofpile—soil.Undertheloadofembankment,thethicknessofcushion,whichwasmadeupofcoarsesand,shouldbe30cmto40cmwhilethepilespacingwas1.5m.Theresearchresultscouldpr
8、ovideref-erenceforthedesignofCFGpilecompositefoundationinthefreewayofthisarea.TheresearchresultsinthispapercouldbeusedasareferenceforthedesignparametersofCFG-pilecompositefoundationsforfreewaysoftfound