表面倾斜可液化地基变形特性振动台试验研究
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摘要
针对砂土液化诱发的地表震陷和地面侧向移动等地震破坏现象,开展了表面倾斜角度为3°、6°、9°的不同可液化地基变形特性的振动台模型试验,测试分析了该类型场地地表竖向变形和侧向大变形的规律及地基孔压分布。研究结果表明:表面倾斜角度为3°、6°时,地基液化时砂土层表层发生了明显的顺坡流动现象,造成砂土层埋深较浅的一侧地基表面下沉和埋设较深的一侧地基表面抬升,大大加剧了液化地基表面的不均匀震陷;表面倾斜角度为9°工况下,底部可液化土层可能发生局部液化现象,未出现液化土层表层的流动和瞬间滑移现象,但为了释放地基内积聚的孔压,在上覆土层较薄一侧地基产生喷砂冒水等严重震害,造成地面表面局部范围的较大震陷。
Based on the seismic damaging phenomenon such as the liquefaction-induced settlement and ground lateral movement,a series of shaking table tests are completed by considering the different surface tilt degrees of the cone-shaped liquefaction foundation with 3°,6°and 9°respectively.With the respect to the test results,the following characteristics are discussed such as the surface vertical deformation,lateral deformation and dynamic pore water pressure.As the results,the downhill liquefaction flow phenomena are very obvious with the surface tilt degrees being 3 and 6 when the foundation is liquefied.At the shallow side of the sand layer,the ground surface settlement takes place obviously and the ground surface uplifts at another side of the foundation.In addition,with the surface tilt degree being 9 degrees,for the thickness of the overlaying soil layer being large,the downhill flow phenomena does not take place.However,in order to release the dynamic pore pressure accumulated in the foundation,the sand boil and other serious seismic damaging phenomena have taken place at the thinner overlaying soil layer which gives rise to more earthquake-induced settlement.
Based on the seismic damaging phenomenon such as the liquefaction-induced settlement and ground lateral movement,a series of shaking table tests are completed by considering the different surface tilt degrees of the cone-shaped liquefaction foundation with 3°,6°and 9°respectively.With the respect to the test results,the following characteristics are discussed such as the surface vertical deformation,lateral deformation and dynamic pore water pressure.As the results,the downhill liquefaction flow phenomena are very obvious with the surface tilt degrees being 3 and 6 when the foundation is liquefied.At the shallow side of the sand layer,the ground surface settlement takes place obviously and the ground surface uplifts at another side of the foundation.In addition,with the surface tilt degree being 9 degrees,for the thickness of the overlaying soil layer being large,the downhill flow phenomena does not take place.However,in order to release the dynamic pore pressure accumulated in the foundation,the sand boil and other serious seismic damaging phenomena have taken place at the thinner overlaying soil layer which gives rise to more earthquake-induced settlement.
引文
[1]蔡晓光,范丽远.地震液化引起地面侧向大变形研究评述[J].防灾科技学院学报,2010,12(1):11～16.
[2]董津城.唐山地震砂土液化的研究[J].工程勘察,1984,(5):7～14.
[3]张荣祥,顾宝和,石兆吉.地基液化失效和隔震的临界孔隙水压力研究[J].工程勘察,1997,(2):5～7.
[4]Hamada,M,Towhata,I,Yasuda,S,Isoyama R.Study of permanent ground displacement induced by seismic liquefaction[J].Computers and Geotechnics,1987,4(4):197～220.
[5]刘颖,谢君斐.砂土震动液化[M].北京:地震出版社,1984.
[6]中国赴日地震考察团.日本阪神大地震考察[M].北京:地震出版社,1995.
[7]王刚,张建民.砂土液化变形的数值模拟[J].岩土工程学报,2007,29(3):403～409.
[8]刘汉龙,周云东,高玉峰.砂土地震液化后大变形特性试验研究[J].岩土工程学报,2002,2(3):142～146.
[9]陈育民,刘汉龙,周云东.液化及液化后砂土的流动特性分析[J].岩土工程学报,2006,9(3):1139～1143.
[10]蔡晓光,袁晓铭,刘汉龙等.近岸水平场地液化侧向大变形机理及软化模量分析方法[J].地震工程与工程振动,2005,25(3):125～131.
[11]Zhaohui Yang,Ahmed Elgamal.Influence of permeability on liquefaction-induced shear deformation[J].Journal of Engineering Mechanics,2002,128(7):720～729.
[12]王炳辉.江苏沿江(海)地区新近沉积土动力特性的试验研究[D].南京:南京工业大学博士学位论文,2010.
[2]董津城.唐山地震砂土液化的研究[J].工程勘察,1984,(5):7～14.
[3]张荣祥,顾宝和,石兆吉.地基液化失效和隔震的临界孔隙水压力研究[J].工程勘察,1997,(2):5～7.
[4]Hamada,M,Towhata,I,Yasuda,S,Isoyama R.Study of permanent ground displacement induced by seismic liquefaction[J].Computers and Geotechnics,1987,4(4):197～220.
[5]刘颖,谢君斐.砂土震动液化[M].北京:地震出版社,1984.
[6]中国赴日地震考察团.日本阪神大地震考察[M].北京:地震出版社,1995.
[7]王刚,张建民.砂土液化变形的数值模拟[J].岩土工程学报,2007,29(3):403～409.
[8]刘汉龙,周云东,高玉峰.砂土地震液化后大变形特性试验研究[J].岩土工程学报,2002,2(3):142～146.
[9]陈育民,刘汉龙,周云东.液化及液化后砂土的流动特性分析[J].岩土工程学报,2006,9(3):1139～1143.
[10]蔡晓光,袁晓铭,刘汉龙等.近岸水平场地液化侧向大变形机理及软化模量分析方法[J].地震工程与工程振动,2005,25(3):125～131.
[11]Zhaohui Yang,Ahmed Elgamal.Influence of permeability on liquefaction-induced shear deformation[J].Journal of Engineering Mechanics,2002,128(7):720～729.
[12]王炳辉.江苏沿江(海)地区新近沉积土动力特性的试验研究[D].南京:南京工业大学博士学位论文,2010.
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