饱和土中大直径缺陷桩振动特性研究
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摘要
为了研究成层饱和土中带缺陷的大直径灌注桩的振动特性,首先基于饱和多孔介质理论和平面应变理论建立饱和土中考虑施工效应影响的桩土纵向振动模型,利用剪切复刚度传递方法得到桩周土体对桩身的竖向作用;然后考虑桩身横向惯性效应,结合边界条件,利用阻抗函数传递方法得到桩顶复阻抗,利用傅里叶逆变换得到桩顶速度时域响应;接着通过与已有理论解和工程实测曲线进行拟合对比,证明本文解的合理性;最后对桩身缺陷特性、桩周土体性质等参数进行分析,结果显示:缺陷的大小、长度和位置、桩身横向惯性效应以及桩周土性质都会对低应变完整性检测结果产生较大影响。
In this paper,the dynamic characteristics of defective large diameter piles cast-in-place in saturated soil are investigated. Firstly,the frictional forces of the soil acting on the pile shaft according to the Biot′s theory of porous elastic medium considering the construction disturbance are obtained by using the complex stiffness transfer method. Then,the dynamic impedance and velocity response of the pile top are obtained considering the transverse inertia effect and combining the boundary conditions. Afterwards,the reliability of the obtained solution is verified by fitting the existing solution to the measured curve. Finally,a parametric study is conducted to give insight to the sensitivity of dynamic characteristics in low-strain integrity testing on defective piles.
In this paper,the dynamic characteristics of defective large diameter piles cast-in-place in saturated soil are investigated. Firstly,the frictional forces of the soil acting on the pile shaft according to the Biot′s theory of porous elastic medium considering the construction disturbance are obtained by using the complex stiffness transfer method. Then,the dynamic impedance and velocity response of the pile top are obtained considering the transverse inertia effect and combining the boundary conditions. Afterwards,the reliability of the obtained solution is verified by fitting the existing solution to the measured curve. Finally,a parametric study is conducted to give insight to the sensitivity of dynamic characteristics in low-strain integrity testing on defective piles.
引文
[1]高广运,杨成斌,高盟,等.持力层对大直径扩底灌注桩竖向承载性状的影响[J].岩土工程学报,2012,34(7):1 184–1 191.(GAO Guangyun,YANG Chengbin,GAO Meng,et al.Influences of bearing stratum on vertical bearing behaviors of large diameter cast-in-place belled piles[J].Chinese Journal of Geotechnical Engineering,2012,34(7):1 184–1 191.(in Chinese))
[2]高盟,高广运,顾宝和,等.一种大直径扩底桩的沉降计算实用方法[J].岩土工程学报,2012,34(8):1 448–1 452.(GAO Meng,GAO Guangyun,GU Baohe,et al.Practical method for settlement calculation of large-diameter belled piles[J].Chinese Journal of Geotechnical Engineering,2012,34(8):1 448–1 452.(in Chinese))
[3]朱斌,杨永垚,余振刚,等.海洋高桩基础水平单调及循环加载现场试验[J].岩土工程学报,2012,34(6):1 028–1 037.(ZHU Bin,YANG Yongyao,YU Zhengang,et al.Field tests on lateral monotonic and cyclic loadings of offshore elevated piles[J].Chinese Journal of Geotechnical Engineering,2012,34(6):1 028–1 037.(in Chinese))
[4]赵春风,李俊,邱志雄,等.广东地区大直径超长钻孔灌注桩荷载传递特性试验研究[J].岩石力学与工程学报,2015,34(4):849–855.(ZHAO Chunfeng,LI Jun,QIU Zhixiong,et al.Experimental research on load transfer of large-diameter and super-long bored pile in Guangdong area[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(4):849–855.(in Chinese))
[5]BIOT M A.Theory of propagation of elastic waves in a fluid-saturated porous solid.I.Low-frequency range[J].Journal of the Acoustical Society of America,2005,28(2):179–191.
[6]BIOT M A.Mechanics of deformation and acoustic propagation in porous media[J].Journal of Applied Physics,2004,33(4):1 482–1 498.
[7]李强,王奎华,谢康和.饱和土中端承桩纵向振动特性研究[J].力学学报,2004,36(4):435–442.(LI Qiang,WANG Kuihua,XIE Kanghe.Vertical vibration of an end bearing pile embedded in saturated soil[J].Acta Mechanica Sinica,2004,36(4):435–442.(in Chinese))
[8]CAI Y,HU X.Vertical vibrations of a rigid foundation embedded in a poroelastic half space[J].Journal of Engineering Mechanics,2010,136(3):390–398.
[9]ZHENG C,KOURETZIS G P,SLOAN S W,et al.Vertical vibration of an elastic pile embedded in poroelastic soil[J].Soil Dynamics and Earthquake Engineering,2015,77(1):177–181.
[10]刘林超,杨骁.基于薄层法的饱和土桩纵向振动研究[J].岩土力学,2010,31(1):92–98.(LIU Linchao,YANG Xiao.Study of longitudinal vibrations of pile in saturated soil based on layer method[J].Rock and Soil Mechanics,2010,31(1):92–98.(in Chinese))
[11]李强,王奎华,谢康和.饱和土中大直径嵌岩桩纵向振动特性研究[J].振动工程学报,2005,18(4):500–505.(LI Qiang,WANG Kuihua,XIE Kanghe.Dynamic response for vertical vibration of large diameter pile in saturated soil[J].Journal of Vibration Engineering,2005,18(4):500–505.(in Chinese))
[12]杨骁,唐洁.成层饱和土中考虑横向惯性的单桩纵向振动[J].岩土力学,2013,34(6):1 560–1 566.(YANG Xiao,TANG Jie.Vertical vibration of single pile with transversal inertia effect in stratified saturated soil[J].Rock and Soil Mechanics,2013,34(6):1 560–1 566.(in Chinese))
[13]LV S,WANG K,WU W,et al.Longitudinal vibration of a pile embedded in layered soil considering the transverse inertia effect of pile[J].Computers and Geotechnics,2014,62(1):90–99.
[14]王奎华,杨冬英,张智卿.基于复刚度传递多圈层平面应变模型的桩动力响应研究[J].岩石力学与工程学报,2008,27(4):825–831.(WANG Kuihua,YANG Dongying,ZHANG Zhiqing.Study on dynamic response of pile based on complex stiffness transfer model of radial multizone plane strain[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(4):825–831.(in Chinese))
[15]王奎华,杨冬英,张智卿.两种径向多圈层土体平面应变模型的对比[J].浙江大学学报:工学版,2009,43(10):1 902–1 908.(WANG Kuihua,YANG Dongying,ZHANG Zhiqing.Comparison on two kinds of radial multi-zone plane strain models[J].Journal of Zhejiang University:Engineering Science,2009,43(10):1 902–1 908.(in Chinese))
[16]LYSMER J,RICHART JR F E.Dynamic response of footings to vertical loading[J].Geotechnical Special Publication,1966,92:1 091–1 117.
[17]GAO L,WANG K,WU J,et al.Analytical solution for the dynamic response of a pile with a variable-section interface in low-strain integrity testing[J].Journal of Sound and Vibration,2017,395:328–340.
[2]高盟,高广运,顾宝和,等.一种大直径扩底桩的沉降计算实用方法[J].岩土工程学报,2012,34(8):1 448–1 452.(GAO Meng,GAO Guangyun,GU Baohe,et al.Practical method for settlement calculation of large-diameter belled piles[J].Chinese Journal of Geotechnical Engineering,2012,34(8):1 448–1 452.(in Chinese))
[3]朱斌,杨永垚,余振刚,等.海洋高桩基础水平单调及循环加载现场试验[J].岩土工程学报,2012,34(6):1 028–1 037.(ZHU Bin,YANG Yongyao,YU Zhengang,et al.Field tests on lateral monotonic and cyclic loadings of offshore elevated piles[J].Chinese Journal of Geotechnical Engineering,2012,34(6):1 028–1 037.(in Chinese))
[4]赵春风,李俊,邱志雄,等.广东地区大直径超长钻孔灌注桩荷载传递特性试验研究[J].岩石力学与工程学报,2015,34(4):849–855.(ZHAO Chunfeng,LI Jun,QIU Zhixiong,et al.Experimental research on load transfer of large-diameter and super-long bored pile in Guangdong area[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(4):849–855.(in Chinese))
[5]BIOT M A.Theory of propagation of elastic waves in a fluid-saturated porous solid.I.Low-frequency range[J].Journal of the Acoustical Society of America,2005,28(2):179–191.
[6]BIOT M A.Mechanics of deformation and acoustic propagation in porous media[J].Journal of Applied Physics,2004,33(4):1 482–1 498.
[7]李强,王奎华,谢康和.饱和土中端承桩纵向振动特性研究[J].力学学报,2004,36(4):435–442.(LI Qiang,WANG Kuihua,XIE Kanghe.Vertical vibration of an end bearing pile embedded in saturated soil[J].Acta Mechanica Sinica,2004,36(4):435–442.(in Chinese))
[8]CAI Y,HU X.Vertical vibrations of a rigid foundation embedded in a poroelastic half space[J].Journal of Engineering Mechanics,2010,136(3):390–398.
[9]ZHENG C,KOURETZIS G P,SLOAN S W,et al.Vertical vibration of an elastic pile embedded in poroelastic soil[J].Soil Dynamics and Earthquake Engineering,2015,77(1):177–181.
[10]刘林超,杨骁.基于薄层法的饱和土桩纵向振动研究[J].岩土力学,2010,31(1):92–98.(LIU Linchao,YANG Xiao.Study of longitudinal vibrations of pile in saturated soil based on layer method[J].Rock and Soil Mechanics,2010,31(1):92–98.(in Chinese))
[11]李强,王奎华,谢康和.饱和土中大直径嵌岩桩纵向振动特性研究[J].振动工程学报,2005,18(4):500–505.(LI Qiang,WANG Kuihua,XIE Kanghe.Dynamic response for vertical vibration of large diameter pile in saturated soil[J].Journal of Vibration Engineering,2005,18(4):500–505.(in Chinese))
[12]杨骁,唐洁.成层饱和土中考虑横向惯性的单桩纵向振动[J].岩土力学,2013,34(6):1 560–1 566.(YANG Xiao,TANG Jie.Vertical vibration of single pile with transversal inertia effect in stratified saturated soil[J].Rock and Soil Mechanics,2013,34(6):1 560–1 566.(in Chinese))
[13]LV S,WANG K,WU W,et al.Longitudinal vibration of a pile embedded in layered soil considering the transverse inertia effect of pile[J].Computers and Geotechnics,2014,62(1):90–99.
[14]王奎华,杨冬英,张智卿.基于复刚度传递多圈层平面应变模型的桩动力响应研究[J].岩石力学与工程学报,2008,27(4):825–831.(WANG Kuihua,YANG Dongying,ZHANG Zhiqing.Study on dynamic response of pile based on complex stiffness transfer model of radial multizone plane strain[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(4):825–831.(in Chinese))
[15]王奎华,杨冬英,张智卿.两种径向多圈层土体平面应变模型的对比[J].浙江大学学报:工学版,2009,43(10):1 902–1 908.(WANG Kuihua,YANG Dongying,ZHANG Zhiqing.Comparison on two kinds of radial multi-zone plane strain models[J].Journal of Zhejiang University:Engineering Science,2009,43(10):1 902–1 908.(in Chinese))
[16]LYSMER J,RICHART JR F E.Dynamic response of footings to vertical loading[J].Geotechnical Special Publication,1966,92:1 091–1 117.
[17]GAO L,WANG K,WU J,et al.Analytical solution for the dynamic response of a pile with a variable-section interface in low-strain integrity testing[J].Journal of Sound and Vibration,2017,395:328–340.