求解液化土表位移两种简化理论模型的比较研究
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摘要
水平液化场地地表往返位移是基础和地下工程抗震设计的关键因素。本文将液化场地单层模型与下卧非液化层的双层模型位移解进行比较,通过参数分析,比较研究单层模型与双层模型位移的差别,得到土层位移是由液化层和非液化层共同决定。仅在液化层与非液化层厚度可比拟且土层为完全液化时,液化层对土表位移起控制作用,场地土层可用单层模型模拟,此外均不能按单层模型进行简化。提出双层模型土层变形四种模式,指出仅在非液化层薄且硬及入射波频率低时,双层模型可以用单层模型简化,但对大多数工况不能进行这样的简化。
Cyclic displacement on horizontal liquefiable sites is a key factor for seismic design of foundations and underground structures. The theoretical displacement solutions to a single-layer model and a double-layer model which model horizontal liquefiable strata are compared. By parameter analysis, the displacements of the two models are comparatively analyzed. The ground surface displacement on liquefied sites is simultaneously determined by liquefied and non-liquefied layers. Only the thicknesses of liquefiable and non-liquefiable layers are not significantly different and the liquefiable layer completely liquefies, then the ground surface displacement is controlled by the displacement of liquefied layer. The horizontal strata can be modeled by a single-layer model. Also if the non-liquefied layer is stiff and thin, meanwhile the frequency of inputted waves is low, and then the double-layer model can be simplified by the single-layer model. But in most actual engineering cases the double-layer model cannot be simplified by a single-layer model.
Cyclic displacement on horizontal liquefiable sites is a key factor for seismic design of foundations and underground structures. The theoretical displacement solutions to a single-layer model and a double-layer model which model horizontal liquefiable strata are compared. By parameter analysis, the displacements of the two models are comparatively analyzed. The ground surface displacement on liquefied sites is simultaneously determined by liquefied and non-liquefied layers. Only the thicknesses of liquefiable and non-liquefiable layers are not significantly different and the liquefiable layer completely liquefies, then the ground surface displacement is controlled by the displacement of liquefied layer. The horizontal strata can be modeled by a single-layer model. Also if the non-liquefied layer is stiff and thin, meanwhile the frequency of inputted waves is low, and then the double-layer model can be simplified by the single-layer model. But in most actual engineering cases the double-layer model cannot be simplified by a single-layer model.
引文
[1]周云东,刘汉龙,高玉峰,等.液化地震液化后大位移室内试验研究探讨[J].地震工程与工程振动,2002,22(1):152-157.
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[3]刘惠珊,徐凤萍,李鹏程.液化引起的地面大位移对工程的影响及其研究现状[J].工程抗震,1997,(2),21-26.
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[5]张建民.地震液化后地基侧向变形对桩基础的影响[C]∥第八届土力学及岩土工程学术会议论文集.北京:万国学术出版社,1999.
[6]袁晓铭,曹振中,孙锐,等.汶川8.0级地震液化特征初步研究[J].岩石力学和工程学报,2009,28(6):1288-1296.
[7]Chen L W,Yuan X M,Cao Z Z,et al.Liquefaction macrophenomena in the great Wenchuan earthquake[J].Earthquake Engineering and En-gineering Vibration,2009,8(2):219-229.
[8]孙锐,袁晓铭,李雨润,等.循环荷载下液化对土层水平往返变形的影响[J].西北地震学报,2009,31(1):8-14.
[9]李学宁,刘惠珊,周根寿.液化层减震机理研究[J].地震工程与工程振动,1992,12(2):84-91.
[10]Towhata I,Park J P,Orense R P.Use of spectrum intensity for immediate detection of subsoil liquefaction[J].Soils and Foundations,1996,36(2):29-44.
[11]廖振鹏.工程波动理论导引[M].北京:科学出版社,1996.
[2]刘汉龙.地震液化区分布范围对地面大位移的影响[J].河海大学学报,2001,29(5):1-6.
[3]刘惠珊,徐凤萍,李鹏程.液化引起的地面大位移对工程的影响及其研究现状[J].工程抗震,1997,(2),21-26.
[4]刘恢先主编.唐山地震震害[M].北京:地震出版社,1989.
[5]张建民.地震液化后地基侧向变形对桩基础的影响[C]∥第八届土力学及岩土工程学术会议论文集.北京:万国学术出版社,1999.
[6]袁晓铭,曹振中,孙锐,等.汶川8.0级地震液化特征初步研究[J].岩石力学和工程学报,2009,28(6):1288-1296.
[7]Chen L W,Yuan X M,Cao Z Z,et al.Liquefaction macrophenomena in the great Wenchuan earthquake[J].Earthquake Engineering and En-gineering Vibration,2009,8(2):219-229.
[8]孙锐,袁晓铭,李雨润,等.循环荷载下液化对土层水平往返变形的影响[J].西北地震学报,2009,31(1):8-14.
[9]李学宁,刘惠珊,周根寿.液化层减震机理研究[J].地震工程与工程振动,1992,12(2):84-91.
[10]Towhata I,Park J P,Orense R P.Use of spectrum intensity for immediate detection of subsoil liquefaction[J].Soils and Foundations,1996,36(2):29-44.
[11]廖振鹏.工程波动理论导引[M].北京:科学出版社,1996.
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