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1、浙江大學(xué)博士學(xué)位論文循環(huán)荷載作用下復(fù)合土與復(fù)合地基性狀研究姓名:候永峰申請(qǐng)學(xué)位級(jí)別:博士專業(yè):巖土工程指導(dǎo)教師:龔曉南2000.4.1浙江人學(xué){,≮i:t淪義摘螢堡查4生塑!!生!!!l/4形摘要當(dāng)前我國(guó)正在大力進(jìn)行交通建設(shè),很多高速公路、機(jī)場(chǎng)跑道是建在深厚軟粘土地基上的。通過(guò)各種地基處理方法形成的復(fù)合地基一般均能滿足穩(wěn)定性和使用要求,但對(duì)工后沉降如何計(jì)算,目前還沒有通用的方法。循環(huán)荷載作用下飽和軟粘土、復(fù)合土及復(fù)合地基的性狀是計(jì)算工后沉降時(shí)必需考慮的問(wèn)題,所以研究循環(huán)荷載作用下復(fù)合土及復(fù)合地基的性狀具有重要意義。本文運(yùn)用HX。100型多功能三軸儀研究了水泥摻入
2、比相同時(shí),不同置換率的復(fù)合土在循環(huán)荷載作用下的性質(zhì),分析了循環(huán)應(yīng)力比、加荷周數(shù)、圍壓對(duì)復(fù)合土應(yīng)變和}L壓的影響。根據(jù)試驗(yàn)結(jié)果計(jì)算出復(fù)合土的軟化指數(shù),通過(guò)回歸分析得出了復(fù)合土軟化指數(shù)和孔壓的計(jì)算公式。通過(guò)動(dòng)態(tài)彈塑性有限元分析了考慮材料應(yīng)變軟化的道路下復(fù)合地基在循環(huán)荷載作用下的性質(zhì),研究了復(fù)合地基加固范圍、置換率和下臥層性質(zhì)變化對(duì)路面變形的影響。對(duì)比了考慮材料應(yīng)變軟化時(shí)與不考慮材料應(yīng)變軟化時(shí),各種因素對(duì)路面變形的影響程度。通過(guò)工程實(shí)例分析和計(jì)算結(jié)果與實(shí)測(cè)結(jié)果的對(duì)比,得出了將荷載簡(jiǎn)化為平面時(shí)的荷載修正系數(shù)。關(guān)鍵詞:循環(huán)荷載循環(huán)應(yīng)力比復(fù)合土加荷周數(shù)復(fù)合地基潞面變形塹里:
3、查蘭竺土蘭篁堡蘭塑墨堡查些一型堅(jiān)坐!—!旦AbstractAtpresent,themeansoftransportationarebeingconstructedingreatforce.Manyspeedwayand1.unwayofairdromeareconstructedondeepsoftclaysThecompositefoundationcanbcuptothemustardofstabilityandusing,butthereisnouniversalmethodforcalculatingthesettlementofbackwork.’F
4、hepropertiesofsaturatedsoftclay,compositesoilandcompositefoundationundercyclicloadingisnecessarytobeconsideredwhencalculatedtheviaticsettlementofbackwork.ThereforitismeaningfultostudypropertiesofsamrNedsoftclays,compositesoilandcompositefoundationundercyclicloading.Throughthedynamict
5、raxialtestingapparatus(Hx一100),underthesamecementmixingratio,thepropertiesofcompositeofdifferentreplacementratiosoilundercyclicloadingarestudied.theeffectofcyclicstressratio.replacementratioandambientstresstothestrainandporepressureofthecompositesoilareanalyzed.Accordingastheresultso
6、ftests,thedegradationindexofcompositesoiliscalculatedandtheformulaforcalculatingthedegradationindexandporepressureisproposedthroughtheregressionanalysisUsingthedynamicelastoplasticfiniteelementmethod,thesettlementofthecompositefoundationunderroadwayisanalyzed.Theeffectsofreinforceare
7、a,replacementratioandthepropertiesofsubstratumtothesettlementofroadsurfacearestudied.’rhrou曲theanalysisofengineeringandthecomparisonofresultsofcalculatingwithresultsofobservation,thecoefficientofrevisingwhenthecalculationmodelisplaneisproposed.Keywords:cyclicloadingstraindegradationp
8、orepressurec