LABORATORY STRAIN-HOLDING TESTS OF SET-UP OF JACKED-IN PILES IN SAND
-
摘要: 工程实践中发现砂土中的挤土桩承载力亦有时效性,超静孔隙水压力消散理论无法解释该现象。利用应力路径三轴仪进行应变保持试验,模拟沉桩及随后的桩周土体的应力状态和物理性质的改变,经分析试验结果得出,砂土中静压桩承载力时效性是由于桩周土体蠕变膨胀引起桩壁上作用的水平应力增大的结果。Abstract: It is well-established that the shaft capacity of piles jacked-in increases with time.In clays,this behaviour arises predominantly from the dissipation of positive excess pore pressures.In sands,this increase in the absence of pore pressure dissipation can't be attributed to the aforementioned mechanisms.A series of triaxial strain-holding tests are conducted,and a hypothesis is proposed to explain pile set-up in sand that an increase in radial stress due to restrained creep dilation of the soil close to the pile shaft causes an increase in shaft resistance.
-
Key words:
- sand /
- bearing capacity of jacked-in pile /
- pile set-up /
- strain-holding tests
-
Axelsson,Gary.Long-Term Set-Up of Driven Piles in Sand[D].Stockholm:Trita-AMI PHD 1035,Division of Soil and RockMechanics,Department of Civil and Environmental Engineering,RoyalInstitute of Technology,2000; [2] ChowF C,Jardine RJ,Nauroy J F,et al.Time-Related Increase inShaft Capacities of Driven Piles in Sand[J].G啨otechnique,1997,47(2):353-361; [3] Lehane B M,Jardine R J,Bond AJ,et al.Mechanisms of ShaftFriction in Sand from Instrumented Piles Tests[J].Journal ofGeotechnical Engineering,ASCE,1993,119(1):19-35; [4] Schmertmann J H.The Mechanical Aging of Soils[J].Journal ofGeotechnical Engineering,ASCE,1991,117(9):1288-1330; [5] Baligh M M.Strain Path Method[J].Journal of GeotechnicalEngineering,Div.ASCE,1985,111(9):1108-1136; [6] Elisabeth TB,Kenichi S.Mechanisms of Setup of Displacement Pilesin Sand:Laboratory Creep Tests[J].Canadian Geotechnical Journal,2005,42(5):1391-1407; [7] White DJ,Bolton MD.Displacement and Strain Paths During Plane-Stain Model Pile Installationin Sand[J].G啨otechnique,2004,54(6):375-397; [8] 孙钧.岩土材料流变及其工程应用[M].北京:中国建筑工业出版社,1999; [9] 维亚洛夫C C.土力学的流变原理[M].北京:科学出版社,1987; [10] Jardine R J,Standing J R,Chow F C.Some Observations of theEffects of Time on the Capacity of Piles Driven in Sand[J].G啨otechnique,2006,56(4):227-244; [11] Bullock PJ,Schmertmann J H,Mcvay MC,et al.Side Shear SetupⅡ:Results fromFlorida Test Piles[J].Journal of Geotechnical andGeoenvironmental Engineering,ASCE,2005,131(3):301-310; [12] Zhao Y.Pile Set-Up in Sand[D].Cambridge,U K:EngineeringDepartment,Cambridge University,2002.
点击查看大图
计量
- 文章访问数: 95
- HTML全文浏览量: 7
- PDF下载量: 56
- 被引次数: 0