回填土场地强震动性质讨论
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摘要
本文旨在讨论位于回填土场地上及回填土场地深挖基坑内的强震动观测仪所获得地震动是否是真实自由场地震动,若不是,其影响如何?结合回填土场地的强震动观测台站建设的实际情形,建立了回填土场地和回填土场地深挖基坑的有限元分析模型,基于集中质量显式动力有限元数值模拟方法,分析了回填土的波速和厚度、基坑尺寸对自由场地震动的影响.同时,提出了通过用重塑土置换回填土以降低回填土对自由场地震动影响的措施,并对重塑土置换回填土的效果进行了数值模拟分析.结果表明:回填土上和回填土深挖基坑内的地震动峰值和反应谱值与原始场地的均有明显的差异,随着回填土厚度和基坑深度的增加,其差异越大;通过重塑土置换回填土可以减小回填土对场地地震动的影响.本文所得关于回填土、基坑和重塑土的影响规律可为回填土场地上强震动观测结果的合理利用以及强震动观测台站建设提供依据.
This paper aims to quantitatively study the impact of backfill and foundation pits on free-field ground motion.A finite element model for this issue is established based on the actual situation.Using the numerical simulation method of the concentrated mass explicit dynamic finite element,we analyze the effects of the shear wave velocity,the thickness of backfill soil,and the size of foundation pit on free-field ground motion.At the same time,the remodeling soil analysis models are established to analyze the effect of remolded soil on free-field ground motion.Theresults show that both the backfill soil and foundation pits can affect the free-field ground motion peaks and the values of response spectrum significantly.With the increase of the thickness of backfill soil and the depth of foundation pits,the influence is more noticeable.Replacing the backfill by remolding soil can reduce the effect of the backfill on the free field.The results can provide a basis for the rational use of the strong ground motion records on the backfill site and the construction of the strong ground motion observation stations.
This paper aims to quantitatively study the impact of backfill and foundation pits on free-field ground motion.A finite element model for this issue is established based on the actual situation.Using the numerical simulation method of the concentrated mass explicit dynamic finite element,we analyze the effects of the shear wave velocity,the thickness of backfill soil,and the size of foundation pit on free-field ground motion.At the same time,the remodeling soil analysis models are established to analyze the effect of remolded soil on free-field ground motion.Theresults show that both the backfill soil and foundation pits can affect the free-field ground motion peaks and the values of response spectrum significantly.With the increase of the thickness of backfill soil and the depth of foundation pits,the influence is more noticeable.Replacing the backfill by remolding soil can reduce the effect of the backfill on the free field.The results can provide a basis for the rational use of the strong ground motion records on the backfill site and the construction of the strong ground motion observation stations.
引文
China Earthquake Administration.2006.DB/T 17-2006Specification for the construction of seismic station strong motion station(in Chinese).Beijing:Seismological Press.
Guan H M,Liao Z P.1997.A method for eliminating instability of multi-transmitting boundary.Earthquake Engineering and Engineering Vibration(in Chinese),17(4):1-8.
Li X J.2014.Technical Guideline for Construction of Earthquake Early Warning System(in Chinese).Beijing:Seismological Press,1-57.
Liao Z P.1984.A finite element method for near-field wave motion in heterogeneous materials.Earthquake Engineering and Engineering Vibration(in Chinese),4(2):1-14.
Liao Z P.1996.Extrapolation non-reflecting boundary conditions.Wave Motion,24(2):117-138.
Liao Z P.1996.Introduction to Wave Motion Theories in Engineering(in Chinese).Beijing:Science Press,1-322.
Liao Z P.1997.Numerical simulation of near-field wave motion.Advances in Mechanics(in Chinese),27(2):193-212.
Liao Z P.1998.A decoupling numerical simulation of wave motion.Developments in Geotechnical Engineering,83:125-140.
Liao Z P,Huang K L,Yang B P,et al.1984.Transient wave transmission boundary.Science in China:Series A(in Chinese),(6):556-564.
Liao Z P,Liu J B.1992a.Fundamental problems in finite element simulation of wave motion.Science in China(Series B),35(11):1353-1364.
Liao Z P,Liu J B.1992b.Numerical instabilities of a local transmitting boundary.Earthquake Engineering&Structural Dynamics,21(1):65-77.
Xie Z N,Liao Z P.2008.A note for the mechanism of highfrequency instability induced by absorbing boundary conditions.Acta Seismologica Sinica(in Chinese),30(3):302-306.
Yang B P,Chen Q B.1992.Application of explicit finite element method in earthquake engineering.World Earthquake Engineering(in Chinese),8(4):31-40.
Yang B P,Yang X M.1997.Seismic response of structures on complex sites.Earthquake Engineering and Engineering Vibration(in Chinese),17(2):10-15.
Zhou Z H,Liao Z P.2001.A measure for eliminating drift instability of the multi-transmitting formula.Acta Mechanica Sinica(in Chinese),33(4):550-554.
关慧敏,廖振鹏.1997.一种改善多次透射边界稳定性的措施.地震工程与工程振动,17(4):1-8.
李小军.2014.地震预警系统建设技术指南.北京:地震出版社,1-57.
廖振鹏.1996.工程波动理论导引.北京:科学出版社,1-322.
廖振鹏.1997.近场波动的数值模拟.力学进展,27(2):193-212.
廖振鹏.1984.近场波动问题的有限元解法.地震工程与工程振动,4(2):1-14.
廖振鹏,黄孔亮,杨柏坡等.1984.暂态波透射边界.中国科学A辑,(6):556-564.
廖振鹏,刘晶波.1992.波动有限元模拟的基本问题.中国科学:B辑,(8):874-882.
谢志南,廖振鹏.2008.人工边界高频振荡失稳机理的一点注记.地震学报,30(3):302-306.
杨柏坡,陈庆彬.1992.显式有限元法在地震工程中的应用.世界地震工程,8(4):31-40.
杨柏坡,杨笑梅.1997.复杂场地上结构地震反应的研究.地震工程与工程振动,17(2):10-15.
中国地震局.2006.DB/T 17-2006地震台站建设规范强震动台站.北京:地震出版社.
周正华,廖振鹏.2001.消除多次透射公式飘移失稳的措施.力学学报,33(4):550-554.
Guan H M,Liao Z P.1997.A method for eliminating instability of multi-transmitting boundary.Earthquake Engineering and Engineering Vibration(in Chinese),17(4):1-8.
Li X J.2014.Technical Guideline for Construction of Earthquake Early Warning System(in Chinese).Beijing:Seismological Press,1-57.
Liao Z P.1984.A finite element method for near-field wave motion in heterogeneous materials.Earthquake Engineering and Engineering Vibration(in Chinese),4(2):1-14.
Liao Z P.1996.Extrapolation non-reflecting boundary conditions.Wave Motion,24(2):117-138.
Liao Z P.1996.Introduction to Wave Motion Theories in Engineering(in Chinese).Beijing:Science Press,1-322.
Liao Z P.1997.Numerical simulation of near-field wave motion.Advances in Mechanics(in Chinese),27(2):193-212.
Liao Z P.1998.A decoupling numerical simulation of wave motion.Developments in Geotechnical Engineering,83:125-140.
Liao Z P,Huang K L,Yang B P,et al.1984.Transient wave transmission boundary.Science in China:Series A(in Chinese),(6):556-564.
Liao Z P,Liu J B.1992a.Fundamental problems in finite element simulation of wave motion.Science in China(Series B),35(11):1353-1364.
Liao Z P,Liu J B.1992b.Numerical instabilities of a local transmitting boundary.Earthquake Engineering&Structural Dynamics,21(1):65-77.
Xie Z N,Liao Z P.2008.A note for the mechanism of highfrequency instability induced by absorbing boundary conditions.Acta Seismologica Sinica(in Chinese),30(3):302-306.
Yang B P,Chen Q B.1992.Application of explicit finite element method in earthquake engineering.World Earthquake Engineering(in Chinese),8(4):31-40.
Yang B P,Yang X M.1997.Seismic response of structures on complex sites.Earthquake Engineering and Engineering Vibration(in Chinese),17(2):10-15.
Zhou Z H,Liao Z P.2001.A measure for eliminating drift instability of the multi-transmitting formula.Acta Mechanica Sinica(in Chinese),33(4):550-554.
关慧敏,廖振鹏.1997.一种改善多次透射边界稳定性的措施.地震工程与工程振动,17(4):1-8.
李小军.2014.地震预警系统建设技术指南.北京:地震出版社,1-57.
廖振鹏.1996.工程波动理论导引.北京:科学出版社,1-322.
廖振鹏.1997.近场波动的数值模拟.力学进展,27(2):193-212.
廖振鹏.1984.近场波动问题的有限元解法.地震工程与工程振动,4(2):1-14.
廖振鹏,黄孔亮,杨柏坡等.1984.暂态波透射边界.中国科学A辑,(6):556-564.
廖振鹏,刘晶波.1992.波动有限元模拟的基本问题.中国科学:B辑,(8):874-882.
谢志南,廖振鹏.2008.人工边界高频振荡失稳机理的一点注记.地震学报,30(3):302-306.
杨柏坡,陈庆彬.1992.显式有限元法在地震工程中的应用.世界地震工程,8(4):31-40.
杨柏坡,杨笑梅.1997.复杂场地上结构地震反应的研究.地震工程与工程振动,17(2):10-15.
中国地震局.2006.DB/T 17-2006地震台站建设规范强震动台站.北京:地震出版社.
周正华,廖振鹏.2001.消除多次透射公式飘移失稳的措施.力学学报,33(4):550-554.