一维渗透力与浮力

发布时间：2018-04-19 09:13

  本文选题：渗透力 + 浮力　； 参考：《力学学报》2017年05期

【摘要】：为简化分析,针对一维渗流问题,研究提出了土力学中渗透力和浮力的两种推导方法,作为传统的宏观尺度孔隙水隔离体法的有益补充.弹性力学平衡微分方程、土力学Terzaghi有效应力方程和流体力学简化Bernoulli方程构成本文分析渗透力和浮力的3个基本方程.在基本方程基础上,容易推导出相应的骨架和孔隙水两种隔离体的平衡微分方程,从而在静力平衡范畴内揭示渗透力和浮力的内涵.单位体积饱和土体的渗透力,源于总水头压力的梯度,而浮力则源于位置水头压力在竖向的梯度,这两者统一于骨架或孔隙水的平衡微分方程.实际工程关注的有效应力计算问题,一般可以直接应用3个基本方程来确定;只有在简化条件下可按渗透力和浮力计算土体中有效应力分布规律.还讨论了若干研究热点问题,重点探讨了当前一种渗透力新定义j=nγ_wi在形式上的合理性以及在实际应用中可能存在的风险,并验证了一维渗透力的一种经典精细化表述结果中考虑渗流速度时间导数的严谨性.在土力学渗透力和浮力问题研究中应重视和正确应用Terzaghi有效应力方程.
[Abstract]:In order to simplify the analysis, two derivation methods of permeability and buoyancy in soil mechanics are proposed to solve the one-dimensional seepage problem, which can be used as a useful supplement to the traditional macro-scale pore water isolator method.The equilibrium differential equation of elastic mechanics, the Terzaghi effective stress equation of soil mechanics and the simplified Bernoulli equation of hydrodynamics constitute three basic equations for the analysis of permeability and buoyancy in this paper.On the basis of the basic equations, it is easy to deduce the corresponding equilibrium differential equations of two isolators, skeleton and pore water, so as to reveal the connotation of permeability and buoyancy in the category of static equilibrium.The permeability of saturated soil per unit volume originates from the gradient of the total head pressure, while the buoyancy comes from the vertical gradient of the position head pressure, which is consistent with the equilibrium differential equation of skeleton or pore water.Three basic equations can be directly used to determine the effective stress calculation problem concerned in practical engineering, and the effective stress distribution law in soil can be calculated according to permeability and buoyancy only under simplified conditions.Some hot research issues are also discussed, with emphasis on the formal rationality of a new definition of penetrability and the possible risks in practical application.It is verified that the time derivative of seepage velocity is considered in a classical refined expression of one dimensional permeability.The effective stress equation of Terzaghi should be paid attention to and applied correctly in the study of soil mechanics permeability and buoyancy.
【作者单位】： 北京交通大学土木建筑工程学院;陕西省公路桥梁与隧道重点试验室;
【基金】：国家自然科学基金(51278028,41172221) 中央高校基本科研业务费专项资金(310821161119,2014JBM087)资助项目
【分类号】：TU43
，

本文编号：1772486