Vibration isolation effects of pile barriers in layered saturated transversely isotropic foundations under moving loads
-
摘要: 利用有限元-边界元耦合法评估了移动荷载下层状横观各向同性饱和土体中排桩的隔振效果。利用有限元法将排桩离散成单桩以及桩单元，基于Bernoulli-Euler梁理论得到桩的有限元矩阵方程；在桩-土边界，土体单元与桩单元进行了等节点离散，并以层状饱和地基的解析层元基本解作为核函数，利用边界积分法得到桩-土界面处地基的柔度矩阵；基于两阶段理论，将侧摩阻力响应与移动荷载直接引起的振动进行耦合，结合边界元法得到饱和地基的边界元方程；考虑Bernoulli-Euler梁和土体之间不发生相对滑移和脱开的位移协调条件，耦合有限元和边界元方程，得到排桩的动力响应方程；计算有无排桩隔振下某一观测点的位移，即可结合隔振理论分析排桩的隔振效率。在验证所提方法准确性的基础上，分析了桩长、桩身刚度、移动荷载速度以及横观各向同性参数对排桩隔振效应的影响。结果表明：最优桩长约等于2倍瑞利波长，超过该值隔振效果提高不大；桩与地基的刚度差越大，隔振效果越好；荷载速度超过剪切波速，桩基隔振表现反而更好。
-
关键词:
- 层状横观各向同性饱和土 /
- 排桩 /
- 移动荷载 /
- 隔振效应 /
- 有限元-边界元耦合法
Abstract: The vibration isolation effects of pile rows in saturated layered transversely isotropic soils due to moving loads are evaluated using the finite-element-boundary-element coupled method. The finite element matrix equations for the pile are obtained based on the Bernoulli-Euler beam theory by discretizing the pile rows into single piles and pile units using the finite element method. At the pile-soil boundary, the soil and pile units are discretized with equal nodes, and the analytical layer-element basic solution for the layered transversely isotropic saturated foundation consolidation problem is used as the kernel function to obtain the flexibility matrix using the boundary integral method. Further, based on the two-stage theory, the influences of lateral friction resistance and the vibration directly caused by the moving loads are coupled, and the boundary element equations are obtained by combining the boundary element method. The displacement coordination conditions of no relative slip and dislocation between the piles and the soils are used to couple the finite element and boundary element equations, and the dynamic response equation for the pile rows is obtained. Then, the displacement of an observation point after the pile rows without and with the pile vibration isolation is calculated separately, and the isolation efficiency is obtained by combining with the vibration isolation theory. The accuracy of the proposed method is verified by comparing with the existing numerical results, and the effects of the load velocity and different pile materials on the vibration isolation effects are analyzed. The results show that two times the Rayleigh wavelength is the optimal pile length, and the vibration isolation effects will not improve greatly beyond the critical value. The greater the difference in stiffness between the pile and foundation, the better the vibration isolation effects. When the load speed exceeds the shear wave speed, the vibration isolation performance -
-
![]()
图 1 移动荷载作用下层状横观各向同性饱和土体中隔振桩基屏障的动力模型
Figure 1. Dynamic model for vibration isolation pile barriers in layered transversely isotropic saturated soils under moving loads
![]()
![]()
图 4 本文在不同桩间距下的平均幅值减小比与有限元解的比对
Figure 4. Comparison between average amplitude reduction ratio for different pile spacings and FE solution
![]()
图 5 不同桩长下在区域-1 < y/λr < 1，0 < x/λr < 2内振幅比Ar的轮廓分布
Figure 5. Contour distribution of amplitude ratio Ar in the region -1 < y/λr < 1, 0 < x/λr < 2 at different pile lengths
![]()
图 6 桩长对振幅比沿x方向上的影响
Figure 6. Effects of pile length on amplitude ratio along x-direction
![]()
图 7 不同桩的刚度下沿x轴的振幅比变化
Figure 7. Variation of amplitude ratio along x-axis for different pile stiffnesses
![]()
图 8 不同桩长下桩的刚度与平均振幅比之间的变化关系
Figure 8. Variation relationship between pile stiffness and average amplitude ratio at different pile lengths
![]()
图 9 不同速度下振幅比沿x轴方向的变化曲线
Figure 9. Variation curves of amplitude ratio along x-axis at different speeds
![]()
图 10 不同桩的刚度下速度对平均振幅比的影响
Figure 10. Effects of velocity on average amplitude ratio at different pile stiffnesses
-
[1] LU J F, XU B, WANG J H. A numerical model for the isolation of moving-load induced vibrations by pile rows embedded in layered porous media[J]. International Journal of Solids and Structures, 2009, 46(21): 3771-3781. doi: 10.1016/j.ijsolstr.2009.06.022
[2] LU J F, XU B, WANG J H. Numerical analysis of isolation of the vibration due to moving loads using pile rows[J]. Journal of Sound Vibration, 2009, 319(3/4/5): 940-962.
[3] ONUR T, DENIZ U, BURAK F N. Assessing vibration isolation performance of single and coupled wave barriers through field experiments[J]. Construction and Building Materials, 2022, 354: 129156. doi: 10.1016/j.conbuildmat.2022.129156
[4] NITISH J, AMARNATH H, PRADIPTA C. Full scale field studies for assessing the vibration isolation performance of single and dual trenches[J]. Transportation Geotechnics, 2023, 39: 100932.
[5] LIANG F Y, LI T D, QIAN Y, et al. Investigating the seismic isolation effect of the cushioned pile raft foundation in soft clay through dynamic centrifuge tests[J]. Soil Dynamics and Earthquake Engineering, 2021, 142: 106554. doi: 10.1016/j.soildyn.2020.106554
[6] CAI C Z, GAO L, HE X H, et al. The surface wave attenuation zone of periodic composite in-filled trenches and its isolation performance in train-induced ground vibration isolation[J]. Computers and Geotechnics, 2021, 139: 104421. doi: 10.1016/j.compgeo.2021.104421
[7] ZHANG X, LU J F. A wavenumber domain boundary element method model for the simulation of vibration isolation by periodic pile rows[J]. Engineering Analysis with Boundary Elements, 2013, 37(7/8): 1059-1073.
[8] LINGS M L, PENNINGTON D S, NASH D F T. Anisotropic stiffness parameters and their measurement in a stiff natural clay[J]. Géotechnique, 2000, 50(2): 109-125. doi: 10.1680/geot.2000.50.2.109
[9] YIMSIRI S, SOGA K. Cross-anisotropic elastic parameters of two natural stiff clays[J]. Géotechnique, 2011, 61(9): 809-814. doi: 10.1680/geot.9.P.072
[10] AI Z Y, CAO Z. Vibration isolation of row of piles embedded in transverse isotropic multi-layered soils[J]. Computers and Geotechnics, 2018, 99: 115-129. doi: 10.1016/j.compgeo.2018.03.002
[11] 艾智勇, 李志雄. 冲刷作用下层状横观各向同性土中群桩水平振动响应[J]. 岩土工程学报, 2016, 38(4): 613-618. doi: 10.11779/CJGE201604004 AI Zhiyong, LI Zhixiong. Horizontal vibration of a pile group in transversely isotropic layered soils under scour conditions[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(4): 613-618. (in Chinese) doi: 10.11779/CJGE201604004
[12] AI Z Y, LI P C, SONG X Y, et al. Analysis of an axially loaded pile in saturated multi-layered soils with anisotropic permeability and elastic superstrata[J]. Computers and Geotechnics, 2018, 98: 93-101. doi: 10.1016/j.compgeo.2018.02.004
[13] YANG S, JIA M C. Analytical layer-element solution for layered transversely isotropic saturated media subjected to rectangular moving loads[J]. Soil Dynamics and Earthquake Engineering, 2023, 171: 107877. doi: 10.1016/j.soildyn.2023.107877
[14] YANG S, JIA M C. Horizontal dynamic behavior of partially embedded pile groups in layer cross-anisotropic poroelastic saturated soils under lateral cyclic and axial coupling loadings[J]. Ocean Engineering, 2023, 281: 114803. doi: 10.1016/j.oceaneng.2023.114803
[15] WOODS R D, BARNETT N E, SAGESSET R. Holography a new tool for soil dynamics[J]. Journal of Geotechnical Engineering Division, ASCE, 1974, 100: 1231-1247. doi: 10.1061/AJGEB6.0000121
[16] TSAI P H, FENG Z Y, JEN T L. Three-dimensional analysis of the screening effectiveness of hollow pile barriers for foundation-induced vertical vibration[J]. Computers and Geotechnics, 2008, 35(3): 489-499. doi: 10.1016/j.compgeo.2007.05.010
-
其他相关附件
下载:
计量
- 文章访问数: 0
- HTML全文浏览量: 0
- PDF下载量: 0
