岩土工程研究

移动荷载作用下非均匀地基的动力响应分析

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  • 1. 兰州理工大学 土木工程学院,甘肃 兰州 730050;2. 兰州理工大学 西部土木工程防灾减灾教育部工程研究中心,甘肃 兰州 730050
周凤玺,男,1979年生,博士,副教授,主要从事岩土力学、复合材料结构力学等方面的研究与教学工作。

收稿日期: 2014-05-14

  网络出版日期: 2018-06-13

基金资助

国家自然科学基金(No. 11162008,No. 51368038);甘肃省高等学校基本科研业务费专项(No. 1104ZTC140);甘肃省环保厅科研项目(No.GSEP-2014-23)。

Analysis of dynamic response of inhomogeneous subgrade under moving loads

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  • 1. School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education, Lanzhou University of Technology, Lanzhou, Gansu 730050, China

Received date: 2014-05-14

  Online published: 2018-06-13

摘要

基于线弹性动力学理论,结合坐标变换,建立了移动荷载作用下非均匀弹性半平面地基的动力控制方程,利用半解析法研究了移动荷载作用下二维非均匀地基的动力响应问题。采用傅里叶(Fourier)级数展开,假设了响应函数的级数形式,通过理论推导获得了剪切模量随深度任意变化的非均匀地基在移动荷载作用下各物理量的解析表达式。考虑土体的剪切模量沿厚度方向按幂函数梯度变化,通过数值算例分析并讨论了地基非均匀参数、荷载移动速度以及地基表面的剪切模量等对地基力学响应的影响规律,并与均质地基的计算结果进行了比较。数值结果表明:地基中各点的竖向位移随着土体表面剪切模量和表征土体非均匀性的梯度因子的增大而减小,随着荷载移动速度的增大而增大。在移动荷载作用下,非均匀地基与均匀地基的动力响应有着显著的区别。

本文引用格式

周凤玺 ,曹永春 ,赵王刚, . 移动荷载作用下非均匀地基的动力响应分析[J]. 岩土力学, 2015 , 36(7) : 2027 -2033 . DOI: 10.16285/j.rsm.2015.07.026

Abstract

Based on the theory of linear elastodynamics, and combined with the coordinate transformation, the dynamic governing equations for a half-plane inhomogeneous subgrade are developed. The dynamic response of a two-dimensional inhomogeneous subgrade subjected to moving loads is analyzed based on a semi-analytical method. Using Fourier series expansion, and assuming the series form of response function, the analytical expressions of various physical quantities are developed for the inhomogeneous subgrade subjected to moving loads, in which the shear modulus can arbitrarily change with depth. Assuming the shear modulus has an exponential distribution with the thickness, a parametric study is presented to illustrate the influence of the foundation soil inhomogeneity and load moving velocity as well as shear modulus at subgrade surface on the dynamical response of foundation soils. The calculated results are compared with the responses of a homogeneous subgrade, showing that the vertical displacement of soil decreases with the increase of the shear modulus at the surface of subgrade and the inhomogeneous gradient index, and increases with the increase of the load moving velocity. Under a moving load, the dynamic responses of inhomogeneous subgrade are significantly different from that of homogeneous subgrade.
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