Boussinesq equation-based model for flow in drainage layer of highway  

作　　者：但汉成 罗苏平 李亮 赵炼恒 

机构地区：[1]School of Civil Engineering,Central South University [2]Guizhou Transportation Planning Survey&Design Academe Co.,Ltd. [3]Administration of Quality Supervision of Hainan Transportation Engineering

出　　处：《Journal of Central South University》2012年第8期2365-2372,共8页中南大学学报（英文版）

基　　金：Project(511114) supported by the Natural Science Foundation of Hainan Province, China;Project(2009YBFZ05) supported by Postgraduate Award of Central South University, China;Project(200731) supported by Traffic Technology Fund of Hunan Province, China;Project(2008BAG10B01) supported by the National Key Technology R&D Program, China

摘　　要：In order to study the water flow in the drainage layer of highway under steady-state condition, one-dimensional （1D） Boussinesq equation-based model with Dupuit-Forchheimer assumption was established and the semi-analytical solutions to predict the water-table height were presented. In order to validate the model, a two-dimensional （2D） saturated flow model based on the Laplace equation was applied for the purpose of the model comparison. The water-table elevations predicted by ID Boussinesq equation-based model and 2D Laplace equation-based model match each other well, which indicates that the horizontal flow in drainage layer is dominated. Also, it validates the 1D Boussinesq equation-based model which can be applied to predict the water-table elevation in drainage layer. Further, the analysis was conducted to examine the effect of infiltration rate, hydraulic conductivity and slope of drainage layer on the water-table elevation. The results show that water-table falls down as the ratio of Is to K decreases and the slope increases. If the aquifer becomes confined by the top of drainage layer due to the larger ratio of Is to K or smaller slope, the solution presented in this work can also be applied to approximate the water-table elevation in unconfined sub-section as well as hydraulic head in the confined sub-section.In order to study the water flow in the drainage layer of highway under steady-state condition, one-dimensional (1D) Boussinesq equation-based model with Dupuit-Forchheimer assumption was established and the semi-analytical solutions to predict the water-table height were presented. In order to validate the model, a two-dimensional (2D) saturated flow model based on the Laplace equation was applied for the purpose of the model comparison. The water-table elevations predicted by 1D Boussinesq equation-based model and 2D Laplace equation-based model match each other well, which indicates that the horizontal flow in drainage layer is dominated. Also, it validates the 1D Boussinesq equation-based model which can be applied to predict the water-table elevation in drainage layer. Further, the analysis was conducted to examine the effect of infiltration rate, hydraulic conductivity and slope of drainage layer on the water-table elevation. The results show that water-table falls down as the ratio of Is to K decreases and the slope increases. If the aquifer becomes confined by the top of drainage layer due to the larger ratio of Is to K or smaller slope, the solution presented in this work can also be applied to approximate the water-table elevation in unconfined sub-section as well as hydraulic head in the confined sub-section.

关 键 词：drainage layer HIGHWAY GROUNDWATER Boussinesq equation seepage face 

分 类 号：U412.23[交通运输工程—道路与铁道工程]