The reservoir leakage problem of the Samanalawewa Hydropower Project, Sri Lanka | |
| Author | Gunatilake, A. A. Jagath Kinsly |
| Call Number | AIT Thesis no. GT-93-30 |
| Subject(s) | Seepage Samanalawewa Hydropower Project Hydroelectric power plants--Sri Lanka |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GT-93-30 |
| Abstract | Severe leakage problem was encountered during the first filling of the Samanalawewa reservoir, Sri Lanka. The Samanalawewa Scheme was aimed to generate electricity by exploiting the 300 m difference in elevation between the two adjacent rivers, Walawe and Katupath Oya. With the completion of lOSm high rock and earth fill dam on the Walawe River, impounding began in June 1991 and the first signs of leakage appeared nine days after the impounding. Intensive grouting operation has been carried out by injecting 15,000 tons of cement through the cutoff grouting adit, excavated in the right abutment. Second trial impounding began in March 1992 and a severe water burst occurred with over 7 cumecs discharge around 320 m downstream of the dam when the reservoir level reached 21 meters below its design height of 100 m. All the piezometers installed in the right abutment which closely responded to reservoir level, dropped by 20 m within 24 hrs by quickly responding to the water burst. The study of the field geological investigation and the analysis and interpretation of existing information on geology, hydrology, geochemistry and grouting operation reveal that the existing 1.6 km long 110 m deep cutoff grout curtain in the right abutment is in effective as it is not deep enough to cutoff the seepage water from the reservoir. The several leakage paths exist along the deep open faults below the grout curtain which are well connected with the highly permeable aquifer in the right Bank. |
| Year | 1993 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GT-93-30 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Prinya Nutalaya; |
| Examination Committee(s) | Balasubramaniam, A.S.;Noppadol Phien-wej Orsmael, J.L. Van; |
| Scholarship Donor(s) | AITAA; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology |