Monitoring results of alborz earth dam during construction

Abstract

Monitoring is one of the most important controlling factors in all earth structure studies. Monitoring is regarded as an important factor in controlling dam security, comparing real action with predicted planning and making good experience and opportunity for future planning. In this paper, we study the pore water pressure, total pressure and settlement in Alborz earth dam by making comparisons between the data taken from the instrument and back analysis on the model. Alborz dam is located in north of Iran. Alborz reservoir was selected to be built on Babolrod River in the conjunction of Gazo and Chakhani. It is within forty-fivekilometers south-east of Babol and 269 kilometers north-east of Tehran. The crest length and width are 838 and 12 (m), the dam height is 78 (m). All the back analysis are achieved by FLAC software from the beginning to the end of the construction, when the dam height is 50 (m). This instrument datum that is installed on earth dam shows that pore water pressure in the core has a normal approach during construction. When the core earth fill height is 50 (m), its maximum pore water pressure coefficient is about 0.5. It is less than its considered amount (0.6). It is expected that it will reach 0.4 at the end of the dam construction. Upstream and downstream shell and core settlement, achieved by data are in turn, 55, 35, and 48 (cm), placed on the earth dam permissible sections which are 1 to 2 percent of the dam height. Meanwhile, as it had been predicted, at the end of the dam construction, core settlement reached 135 cm. Generally, all of the installed instruments worked properly.