A Study of Seepage through Earth Dams with Chimney or Horizontal Filters.

Khalaf Allah, S.; G. Abdallah, M.; El-Masry, A.; S. El-Alfy, K.

doi:10.21608/bfemu.2022.222269

A Study of Seepage through Earth Dams with Chimney or Horizontal Filters.

Document Type : Research Studies

Authors

¹ Assistance Lecturer, Irrigation and Hydraulics Engineering Department, Faculty of Engineering, Mansoura University, Egypt.

² Associate Professor, Irrigation and Hydraulics Engineering Department, Faculty of Engineering, Mansoura University, Egypt.

³ Professor of Irrigation and Hydraulics Engineering Department, Faculty of Engineering, Mansoura University, Egypt.

10.21608/bfemu.2022.222269

Abstract

This research paper aims to study the effect of both chimney and horizontal filters separately on seepage characteristics (free water surface, seepage face length and seepage discharge) through earth dams based an impervious base. This study was conducted through both the experimental method by sand box model and the numerical method by boundary element method (BEM).
Also, the effect of either chimney or horizontal filters on seepage characteristic was included. Comparison between the experimental data and the corresponding numerical results for each type of filters was carried out. Also, a comparison between chimney and horizontal filters was presented. It was found that for the same cross section of the earth dam, decreasing the distance between the dam inlet face and the filter position (D) for two types of filters resulting in lowering free water surface, increasing seepage face length, and increasing the seepage flow rate. The seepage face length S_{r for chimney and horizontal}filters were less than the height of exit point for dam without filter, Also the relative seepage face length S_r/S_wf for chimney drain was larger than the corresponding value for horizontal filter by an average difference value of 58,58%. Although the relative seepage discharge q_sher/q_wsfor horizontal filter was less than that for chimney filter, the seepage discharge, q_frame for both the horizontal and the chimney filters were greater than the seepage discharge through dam without filter.
Concerning filter volume, horizontal filter is preferred on chimney filter to reduce the volume of used material.

Main Subjects