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1、第39卷第2期煤田地質(zhì)與勘探Vb1.39NO.22011年4月COALGB0】L()GY&E.0Rr10NApr.2011文章編號(hào):1001—1986(2011)o2-0047—05列車振動(dòng)荷載作用下原狀黃土動(dòng)力特性試驗(yàn)萬(wàn)戰(zhàn)勝,楊,王家鼎(1.長(zhǎng)安大學(xué)公路學(xué)院,陜西西安710064;2.中煤西安設(shè)計(jì)工程有限責(zé)任公司,陜西西安,710054;3.西北大學(xué)地質(zhì)系大陸動(dòng)力學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室,陜西西安710069)摘要:在動(dòng)三軸試驗(yàn)的基礎(chǔ)上,對(duì)列車振動(dòng)荷載作用下原狀黃土的動(dòng)力特性進(jìn)行研究。試驗(yàn)結(jié)果表明:原狀黃土在一定的動(dòng)應(yīng)力作用下,應(yīng)變隨著振次的增大而增大,隨固結(jié)應(yīng)力的增大而減小。應(yīng)變與動(dòng)應(yīng)力在一定
2、條件下近似為雙曲線模型。當(dāng)動(dòng)應(yīng)力比較小時(shí),應(yīng)變與動(dòng)應(yīng)力呈近似的直線關(guān)系,但隨著動(dòng)應(yīng)力增大超過(guò)了某一臨界值時(shí),原狀黃土所產(chǎn)生的應(yīng)變急劇增加,且增加速率隨著振動(dòng)次數(shù)的增加而增加。在一定的振動(dòng)次數(shù)下,土樣的應(yīng)變隨振動(dòng)頻率的增大而減小,且頻率越小的土樣越先出現(xiàn)轉(zhuǎn)折點(diǎn)。原狀黃土在固結(jié)應(yīng)力比為1時(shí),動(dòng)彈性模量隨著動(dòng)應(yīng)變的增加而減小,且逐漸趨于穩(wěn)定。動(dòng)阻尼比隨應(yīng)變?cè)龃鬀](méi)有明顯的增大趨勢(shì),分布比較離散,但其值均在0.10~0.30的范圍以內(nèi)變化。關(guān)鍵詞:列車振動(dòng)荷載;原狀黃土;動(dòng)應(yīng)力;動(dòng)應(yīng)變;動(dòng)彈性模量;動(dòng)阻尼比中圖分類號(hào):TU4文獻(xiàn)標(biāo)識(shí)碼:ADOI:10.3969/j.issn.1001—1986.20
3、11.02.O1lExperimentalstudyondynamicpropertiesofintactloessundertrainvibratingloadWANZhansheng.YANGZhe.WANGJiading(1.HighwayCollege,Chang~nUniversity,30'an710064,China;2.ChinaCoalXi"anDesigneeringCo.,Ltd,Xi'an710054,China;3.GeologicalDepartmentofNorthwestUniversity,StateKeyLaboratoryofContinentalDy
4、namics,Xi'an710069,China)Abstract:Basedonalotofdynamictriaxialtests.somedynamiccharacteristicsonintactloessunderthetrainvi.brationloadarestudies.Thetestresultsshowedthatwhentheintactloesswasundercertaindynamicstress,strainincreasedwiththeincreaseofthenumberofvibration.a(chǎn)nddecreasedwiththedecreaseof
5、consOlidatiOnstress.Therelationbetweenstressandstraincanbefittedwithhyperbolicmodelundercertainconditions.Whendynamicstresswassmaller,straincouldbefittedlinearlywithdynamicstress.Butwithdynamicstressincreasedmorethanacertainthreshold,strainofintactloesswouldbeincreaseddramatically.Andthegrowthrate
6、ofstrainincreasedwiththeincreaseofthenumberofvibration.Underthecertainnumberofvibration,strainofloessdecreasedwiththeincreaseofvibrationfrequency.Andthefrequencywassmaller,theturningpointappearedearlier.Dynamicmodulusofintactloessdecreasedwiththeincreaseofdynamicstrainandthetrendwasbasicallysimila
7、rwhenisequalto1.Dynamicdampingratiodidnothaveobviousincreasingtrendbuthadscatterdistributionwhenthestrainincreased.itsdiscretevalueswereintherangeof0.10to0.30.Keywords:trainvibratingload;intactloess;dynamicstress