COMPARISON OF PRE-CONSTRUCTION AND POST CONSTRUCTION SEEPAGE FOR 17.4 MW SATPARA DAM PROJECT, SKARDU

Abstract

This research has addressed typical geological complexities through performance evaluation of
selective foundation seepage control features for embankment dams. Many researchers like Pack (2000)
introduced use of hazard/factual examination through proper site-explicit designing evaluations as the standard
methodology for foundation assessment of dams regardless of the restricted extent of examinations. In that
capacity, 2-DQseepage examination replicas for heterogeneity foundations either utilize a similar foundation
with a careful K-esteem/K-work related with two-sheet methodology, for example a prevailing foundation sheet
by moderately permeable region in middle. The haphazardness of deposition conditions identified with greatest
heterogeneity foundations isn't tended to all things considered for traditional 2-D drainage examinations.
The study is based on case history of Satpara Dam Project founded over moraine deposits. Seepage modelling
was carried for ‘as-designed’ seepage mitigation measures under 2-D sectional flow model for different case
scenarios using Plaxis 8.6. Availablelprojectldatalfrom Sevenlyearsloflconsecutiveloperation showed that
conservation level and consequently a steady state condition was not achieved. Model study shows that as the
Water level increases the seepage value increases simultaneously whereas, real time data collected shows that
seepage decreases with the passage of time so both are inversely proportional to each other. Actual Seepage
percentage has reduced upto 13% corresponding to the same levels achieved during the last seven impounding
which shows that with time seepage reduces. Data for almost 80 instruments was used to develop state reservoir
and the analysis was done by taking level for a particular period which was retained for at least 5 days for the
last 6 impounding’s. Model study shows that as the Water level increases the seepage value increases
simultaneously whereas, real time data collected shows that seepage decreases with the passage of time so both
are inversely proportional to each other. It was observed that during the course of operation of the Dam the
seepage measured indicating that seepage control measures taken for the dam is effective and working properly.