不同厚度饱和砂土中群桩结构动力响应试验研究
|
摘要
液化土中桩基础动力响应规律一直是工程抗震领域关注的热点问题。本文基于非液化砂土和不同厚度饱和砂土中的2×2群桩结构模型振动台试验,通过输入一定峰值加速度和频率的正弦波,对群桩在非液化土层和两种不同厚度饱和砂土层中的横向动力响应特性进行振动台试验研究。研究结果表明:在正弦波输入情况下,非液化砂土中群桩承台加速度和位移时程与台面输入时程相比,波形变化规律与峰值大小均相差不大;而对两种不同厚度饱和砂土中承台加速度和位移峰值放大较多,在相对较薄的饱和砂土中群桩承台加速度峰值较台面输入放大了1.83倍,较台面输出位移峰值放大了1.58倍;在相对较厚的饱和砂土中承台加速度和位移峰值则分别放大了2.18倍和1.91倍,说明在相同输入条件下,较厚的饱和砂土在发生液化后群桩承台的动力响应更加显著。
The dynamic response law of pile foundations on liquefied soil is a perennial hot topic in the field of earthquake resistance engineering.In this work,the lateral dynamic response characteristics of pile groups in a nonliquefied soil layer and saturated sand layers with two different thicknesses are studied under the input of a sine wave with a certain peak acceleration and frequency through the model shaking table tests of 2×2 pile groups.Results show that under the input of the sine wave,the time histories of acceleration and displacement at the pile cap in nonliquefied sand are not significantly different from those of the input.The peak acceleration and peak displacement at the pile cap drastically increase in saturated sand with two different thicknesses.Specifically,the peak acceleration and peak displacement at the pilecap are magnified by 1.83 and 1.58 orders,respectively,in thin saturated sand,and by 2.18 and 1.91 orders,respectively,in thick saturated sand.Under the same input condition after liquefaction,the dynamic response of the pile cap is more remarkable in thick saturated sand than that in thin saturated sand.
The dynamic response law of pile foundations on liquefied soil is a perennial hot topic in the field of earthquake resistance engineering.In this work,the lateral dynamic response characteristics of pile groups in a nonliquefied soil layer and saturated sand layers with two different thicknesses are studied under the input of a sine wave with a certain peak acceleration and frequency through the model shaking table tests of 2×2 pile groups.Results show that under the input of the sine wave,the time histories of acceleration and displacement at the pile cap in nonliquefied sand are not significantly different from those of the input.The peak acceleration and peak displacement at the pile cap drastically increase in saturated sand with two different thicknesses.Specifically,the peak acceleration and peak displacement at the pilecap are magnified by 1.83 and 1.58 orders,respectively,in thin saturated sand,and by 2.18 and 1.91 orders,respectively,in thick saturated sand.Under the same input condition after liquefaction,the dynamic response of the pile cap is more remarkable in thick saturated sand than that in thin saturated sand.
引文
[1]李雨润,魏星,梁艳,等.液化土—桩—承台结构横向动力响应分析方法研究综述[J].地震工程与工程振动,2012,32(3):180-186.LI Yurun,WEI Xing,LIANG Yan,et al.State-of-art of Study on Dynamic Interaction of Liquefiable Soil-Pile-Cap Structure[J].Earthquake Engineering and Engineering Vibration,2012,32(3):180-186.
[2]凌贤长,王东升.液化场地桩—土—桥梁结构动力相互作用振动台试验研究进展[J].地震工程与工程振动,2002,22(4):51-59.LING Xianzhang,WANG Dongsheng.Study on Shaking Table Test for Seismic Interaction of Pile-Soil-Bridge Structure in Case of Soil Liquefaction Caused by Earthquake[J].Earthquake Engineering and Engineering Vibration,2002,22(4):51.59.
[3]王睿,张建民,张嘎.侧向流动地基单桩基础离心机振动台试验研究[J].工程力学,2012,29(10):98-105.WANG Rui,ZHANG Jianmin,ZHANG Ga.Centrifuge Shaking Table Test on Single Pile in Lateral Spreading Soil[J]Engineering Mechanics,2012,29(10):98-105.
[4]HUSSIEN M N,TOBITA T,IAI S,et al.Soil-Pile-Structure Kinematic and Inertial Interaction Observed in Geotechnical Centrifuge Experiments[J].Soil Dynamics and Earthquake Engineering,2016,89:75-84.
[5]梁发云,陈海兵,黄茂松,等.结构—群桩基础地震响应离心振动台模型试验[J].建筑结构学报,2016,37(9):134-141.LIANG Fayun,CHEN Haibing,HUANG Maosong,et al.Model Test on Seismic Response of Superstructure and Pile Group[J].Journal of Building Structures,2016,37(9):134-141.
[6]KT Chau,CY Shen.Nonlinear Seismic Soil-pile-structure Interactions:Shaking Table Testsand FEM Analyses[J].Soil Dynamics and Earthquake Engineering,2009,29(2):300-310.
[7]袁晓铭,李雨润,孙锐.地面横向往返运动下可液化土层中桩基响应机理[J].土木工程学报,2008,41(9):103-110.YUAN Xiaoming,LI Yurun,SUN Rui.Mechanism of Pile Foundation Response in Liquefiable Soils Under Seismic Cyclic Ground Motion[J].China Civil Engineering Journal,2008,41(9):103-110.
[8]李雨润,张中乐,魏星,等.FBG传感系统在桩基侧向动力响应中的应用研究[J].地震工程与工程振动,2013,33(2):185-191.LI Yurun,ZHANG Zhongle,WEI Xing,et al.Application of FBG Sensing System in Lateral Dynamic Response of Pile[J].Earthquake Engineering and Engineering Vibration,2013,33(2):185-191.
[9]李程程,曹振中,李瑞山.场地液化侧移等级判别标准及其可靠性分析[J].岩土工程学报,2016,38(9):1668-1677.LI Chengcheng,CAO Zhenzhong,LI Ruishan.Assessment Criterion for Level of Liquefaction-induced Lateral Spread and Its Reliability Analysis[J].Chinese Journal of Geotechnical Engineering,2016,38(9):1668-1677.
[10]王海,王永志,刘荟达,等.伺服电机驱动振动台研制及系统性能评价[J].重庆交通大学学报(自然科学版),2017,36(4):114-120.WANG Hai,WANG Yongzhi,LIU Huida,et al.Development of Servo-motor Driven Shaking Table and Performance Assessment of Its System[J].Journal of Chongqing Jiaotong University(Natural Science),2017,36(4):114-120.
[11]孙海峰,景立平,王宁伟,等.振动台多功能叠层剪切箱研制[J].岩石力学与工程学报,2011,30(12):2498-2506.SUN Haifeng,JING Liping,WANG Ningwei,et al.Development of Multifunctional Laminar Shear Container for Shaking Table Test[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(12):2498-2506.
[12]马险峰,孔令刚,方薇,等.砂雨法试样制备平行试验研究[J].岩土工程学报,2014,36(10):1791-1801.MA Xianfeng,KONG Linggang,FANG Wei,et al.Parallel Tests on Preparation of Samples with Sand Pourer[J].Chinese Journal of Geotechnical Engineering,2014,36(10):1791-1801.
[13]叶涛萍.振动台试验结构模型若干相似问题研究[D].邯郸:河北工程大学,2013.YE Taoping.The Studying of Some Similar Problems in Shaking Table Test Structure Model[D].Handan:Hebei Univwesity of Engineering,2013.
[14]姜忻良,徐炳伟,李竹.土-桩-结构振动台模型试验相似理论及其实施[J].振动工程学报,2010,23(2):225-229.JIANG Xinliang,XU Bingwei,LI Zhu.Similitude Laws and Its Application in Shaking Table Test of Soil-Pile-Structure Interaction System[J].Journal of Vibration Engineering,2010,23(2):225-229.
[2]凌贤长,王东升.液化场地桩—土—桥梁结构动力相互作用振动台试验研究进展[J].地震工程与工程振动,2002,22(4):51-59.LING Xianzhang,WANG Dongsheng.Study on Shaking Table Test for Seismic Interaction of Pile-Soil-Bridge Structure in Case of Soil Liquefaction Caused by Earthquake[J].Earthquake Engineering and Engineering Vibration,2002,22(4):51.59.
[3]王睿,张建民,张嘎.侧向流动地基单桩基础离心机振动台试验研究[J].工程力学,2012,29(10):98-105.WANG Rui,ZHANG Jianmin,ZHANG Ga.Centrifuge Shaking Table Test on Single Pile in Lateral Spreading Soil[J]Engineering Mechanics,2012,29(10):98-105.
[4]HUSSIEN M N,TOBITA T,IAI S,et al.Soil-Pile-Structure Kinematic and Inertial Interaction Observed in Geotechnical Centrifuge Experiments[J].Soil Dynamics and Earthquake Engineering,2016,89:75-84.
[5]梁发云,陈海兵,黄茂松,等.结构—群桩基础地震响应离心振动台模型试验[J].建筑结构学报,2016,37(9):134-141.LIANG Fayun,CHEN Haibing,HUANG Maosong,et al.Model Test on Seismic Response of Superstructure and Pile Group[J].Journal of Building Structures,2016,37(9):134-141.
[6]KT Chau,CY Shen.Nonlinear Seismic Soil-pile-structure Interactions:Shaking Table Testsand FEM Analyses[J].Soil Dynamics and Earthquake Engineering,2009,29(2):300-310.
[7]袁晓铭,李雨润,孙锐.地面横向往返运动下可液化土层中桩基响应机理[J].土木工程学报,2008,41(9):103-110.YUAN Xiaoming,LI Yurun,SUN Rui.Mechanism of Pile Foundation Response in Liquefiable Soils Under Seismic Cyclic Ground Motion[J].China Civil Engineering Journal,2008,41(9):103-110.
[8]李雨润,张中乐,魏星,等.FBG传感系统在桩基侧向动力响应中的应用研究[J].地震工程与工程振动,2013,33(2):185-191.LI Yurun,ZHANG Zhongle,WEI Xing,et al.Application of FBG Sensing System in Lateral Dynamic Response of Pile[J].Earthquake Engineering and Engineering Vibration,2013,33(2):185-191.
[9]李程程,曹振中,李瑞山.场地液化侧移等级判别标准及其可靠性分析[J].岩土工程学报,2016,38(9):1668-1677.LI Chengcheng,CAO Zhenzhong,LI Ruishan.Assessment Criterion for Level of Liquefaction-induced Lateral Spread and Its Reliability Analysis[J].Chinese Journal of Geotechnical Engineering,2016,38(9):1668-1677.
[10]王海,王永志,刘荟达,等.伺服电机驱动振动台研制及系统性能评价[J].重庆交通大学学报(自然科学版),2017,36(4):114-120.WANG Hai,WANG Yongzhi,LIU Huida,et al.Development of Servo-motor Driven Shaking Table and Performance Assessment of Its System[J].Journal of Chongqing Jiaotong University(Natural Science),2017,36(4):114-120.
[11]孙海峰,景立平,王宁伟,等.振动台多功能叠层剪切箱研制[J].岩石力学与工程学报,2011,30(12):2498-2506.SUN Haifeng,JING Liping,WANG Ningwei,et al.Development of Multifunctional Laminar Shear Container for Shaking Table Test[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(12):2498-2506.
[12]马险峰,孔令刚,方薇,等.砂雨法试样制备平行试验研究[J].岩土工程学报,2014,36(10):1791-1801.MA Xianfeng,KONG Linggang,FANG Wei,et al.Parallel Tests on Preparation of Samples with Sand Pourer[J].Chinese Journal of Geotechnical Engineering,2014,36(10):1791-1801.
[13]叶涛萍.振动台试验结构模型若干相似问题研究[D].邯郸:河北工程大学,2013.YE Taoping.The Studying of Some Similar Problems in Shaking Table Test Structure Model[D].Handan:Hebei Univwesity of Engineering,2013.
[14]姜忻良,徐炳伟,李竹.土-桩-结构振动台模型试验相似理论及其实施[J].振动工程学报,2010,23(2):225-229.JIANG Xinliang,XU Bingwei,LI Zhu.Similitude Laws and Its Application in Shaking Table Test of Soil-Pile-Structure Interaction System[J].Journal of Vibration Engineering,2010,23(2):225-229.