基于COMSOL的非饱和土中单桩垂直动力特性研究

PDF(1243 KB)

振动与冲击 ›› 2024, Vol. 43 ›› Issue (12) : 46-52.

论文

叶梓1,2，陈永辉1,2，孔纲强1,2，陈庚1,2，徐洁1,2，胡楠1,2

作者信息 +

Vertical dynamic analysis of the pile in unsaturated soils based on COMSOL

YE Zi1,2，CHEN Yonghui1,2，KONG Gangqiang1,2，CHEN Geng1,2，XU Jie1,2，HU Nan1,2

Author information +

文章历史 +

摘要

地下水位线往往决定了浅层地表存在大量的非饱和土，其动力特性与饱和介质或单相介质相比存在明显的差异，而这部分非饱和土常常是与单桩接触的主要材料，对单桩的动力行为影响显著。本文考虑动力受荷单桩周边土体的非饱和特性，基于非饱和多孔弹性介质的波动方程、单桩运动方程与边界条件，利用多物理仿真软件COMSOL中的偏微分方程（Partial Differential Equation， PDE）模块构建了非饱和土与单桩动力相互作用的数学模型，并考虑土的成层性、横观各向同性和纵向非均质性。在与现有文献对比验证COMSOL模型正确性后，设计多组数值算例，讨论土体饱和度、地层非均质性等因素对单桩垂直动力阻抗的影响。

Abstract

The groundwater level determines that there is a large number of unsaturated soils on the soil surface, and its dynamic characteristics are significantly different from those of saturated medium or single-phase medium. As the main medium interacting with piles, unsaturated media have a critical effect on the dynamic behavior of piles. In this paper, considering the unsaturated characteristics of the soil around a dynamically loaded pile, based on the wave equation of the unsaturated poroelastic medium, the motion equation of the pile and the boundary condition, the Partial Differential Equation module in COMSOL Multiphysics software is used to establish a dynamic mathematical model of the interaction between the pile and the unsaturated soil with complex characteristics, such as stratification, transverse isotropy, inhomogeneity and so on. Meanwhile, several complex characteristics of soils and piles can also be reflected in this model. After verifying the correctness of the COMSOL model by comparing with the existing literature, a series of numerical examples were designed to discuss the influence of factors such as the soil saturation and inhomogeneity on the vertical dynamic impedance of a pile.

导出引用

叶梓1,2，陈永辉1,2，孔纲强1,2，陈庚1,2，徐洁1,2，胡楠1,2. 基于COMSOL的非饱和土中单桩垂直动力特性研究[J]. 振动与冲击, 2024, 43(12): 46-52

YE Zi1,2，CHEN Yonghui1,2，KONG Gangqiang1,2，CHEN Geng1,2，XU Jie1,2，HU Nan1,2. Vertical dynamic analysis of the pile in unsaturated soils based on COMSOL[J]. Journal of Vibration and Shock, 2024, 43(12): 46-52

参考文献

[1] WANG K, WU W, ZHANG Z, et al. Vertical dynamic response of an inhomogeneous viscoelastic pile. Computers and Geotechnics[J]. 2010,37(4):536-544. [2] 刘鑫,王奎华,涂园.双向非均质土中填砂竹节管桩纵向振动理论与试验研究[J].振动与冲击,2020,39(14):43-52+68. LIU Xin, WANG, Kui-hua, TU, yuan. Theoretical and experimental study on the longitudinal vibration of sand-filled nodular pipe piles in bidirectional inhomogeneous soil [J]. Journal of Vibration and Shock, 2012,25(2):72-80. [3] 郑长杰, 丁选明 ,栾鲁宝.黏弹性地基中管桩水平动力特性分析[J]. 岩土力学, 2017,38(01):26-32+40. ZHENG Changjie, DING Xuanming, LUAN Lubao. Analysis of lateral dynamic response of pipe pile in viscoelastic soil layer[J]. Rock and Soil Mechanics, 2017, 38(1):26-32+40. [4] LU J, XU B, WANG J, et al. Dynamic responses of a pile embedded in a layered poroelastic half-space to a harmonic axial loading[J]. Acta Mechanica, 2009,207(1-2):29-49. [5] CAI Y, HU X. Vertical vibrations of a rigid foundation embedded in a poroelastic half space. Journal of Engineering Mechanics[J]. 2010,136(3):390-398. [6] DING X, LUAN L, ZHENG C, et al. Influence of the second-order effect of axial load on lateral dynamic response of a pipe pile in saturated soil layer[J]. Soil Dynamics and Earthquake Engineering, 2017,103:86-94. [7] 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, 2015,77:177-181. [8] CUI C, ZHANG S, YANG G, et al. Vertical vibration of a floating pile in a saturated viscoelastic soil layer overlaying bedrock[J]. Journal of Central South University, 2016,23(1):220-232. [9] XIAO S, WANG K, GAO L, et al. Dynamic characteristics of a large-diameter pile in saturated soil and its application[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2018,42(11):1255-1269. [10] XIAO S, HU A, WANG K, et al. Dynamic response of a large-diameter pile with variable section in layered saturated soil considering construction disturbance effect[J]. Marine Georesources & Geotechnology, 2019,37(3):339-348. [11] 赵密, 黄义铭 ,王丕光, 等.桩顶水平动荷载作用下水-桩-土相互作用的解析解[J].岩土工程学报,2022,44(5):907-915. ZHAO Mi, HUANG Yi-Ming, Wang Pi-Guang, et al. Analytical solution for water-pile-soil interaction under horizontal dynamic loads on pile head. Chinese Journal of Geotechnical Engineering, 2022, 44(5):907-915. [12] 王珏, 高玉峰. 分数导数描述的层状饱和土中考虑扰动效应的直桩垂直阻抗[J]. 振动与冲击, 2020,39(4):185-192, 198. WANG Jue, GAO, Yu-feng. Vertical impedance of a straight pile embedded in disturbed layered saturated soil described by fractional viscoelastic model[J]. Journal of Shock and Vibration, 2020, 39(4):185-192, 198. [13] SMEULDERS D M J, DE LA ROSETTE J P M, VAN DONGEN M E H. Waves in partially saturated porous media[J]. Transport in Porous Media, 1992,9(1-2):25-37. [14] GEORGIADIS K, POTTS D M, ZDRAVKOVIC L. The influence of partial soil saturation on pile behaviour[J]. Géotechnique, 2003,53(1):11-25. [15] 章敏, 王星华, 冯国瑞.非饱和土中端承桩水平振动特性研究[J]. 岩土力学, 2015,36(2):409-422. ZHANG Min, WANG Xing-hua, FENG Guo-rui. Horizontal vibration of an end-bearing pile in unsaturated soil[J]. Rock and Soil Mechanics. 2015,36(02):409-422. [16] 杨紫健, 吴文兵, 张云鹏, 等. 考虑竖向荷载影响的非饱和地基中桩的水平振动[J]. 岩石力学与工程学报, 2022,41(S1):2979-2990. YANG Zi-jian, WU Wen-bing, ZHANG Yun-peng, et al. Horizontal vibration of piles in unsaturated foundations considering vertical loads [J]. Chinese Journal of Rock Mechanics and Engineering, 2022,41(S1):2979-2990. [17] ZHANG M, WANG X, YANG G, et al. Solution of dynamic Green's function for unsaturated soil under internal excitation[J]. Soil Dynamics and Earthquake Engineering, 2014,64:63-84. [18] SHAN Y, MA W, XIANG K, et al. Vertical dynamic response of a floating pile in unsaturated poroelastic media based on the fictitious unsaturated soil pile model[J]. Applied Mathematical Modelling, 2022,109:209-228. [19] YE Z, AI Z Y. Vertical dynamic response of a pile embedded in layered transversely isotropic unsaturated soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2022,148(1):4021169. [20] COMSOL Multiphysics Modeling Guide: Version 5.5. Stockholm[M]. Sweden: COMSOL AB, 2019. [21] 孟庆娟. 饱和土中周期性排桩的减振特性研究[D]. 北京: 北京交通大学, 2019. Meng Qing-juan. Vibration attenuation of plane waves by periodic pile barriers in saturated soil[D]. Beijing: Beijing Jiaotong University, 2019.