Showing 2 results for Alborz Dam
Volume 4, Issue 2 (5-2011)
Abstract
The Alborz dam rock foundation is composed of marl and sandstone. With regard to the proposed plan for the grout curtain in marly rocks (relatively soft and plastic( which is significantly different from the hard and brittle rocks, the boreholes spacing (influence radius slurry), injection pressure (resistance rock), and even the composition and concentration of slurry are important. In the present paper, in order to evaluate the grout curtain of Alborz Dam, emphasis has been placed on two important parameters, namely, the coefficient of permeability and cement take. The results of cement take suggest that the distance between the primary boreholes is long and there is no proper connection between the primary and secondary boreholes. Moreover, grouting results of the fifth and sixth series of grout holes imply that the depth of some of the sixth series of grout holes has not been attained at the water tightening surface. A review of the rate of the cement take - time - pressure graphs and cement take - time graphs on the right abutment indicates that the injection pressure has not been applied in accordance to marly rocks leading to unfavorable phenomenon of opening and closing of joints (hydrojacking). Notably, the check holes results on the right abutment indicate that water tightening at this area has been provided a satisfactory and acceptable job.
Maryam Nikooee, Ali Noorzad, Kaveh Ahangari,
Volume 7, Issue 2 (3-2014)
Abstract
Determination of stress in earthfill dams is one of the most important parameters in dam safety studies. Stress monitoring can be done using total pressure cells which are typically installed during construction. The cell is installed with its sensitive surface in direct contact with the soil to measure total stress of soil and in combination with piezometers to measure pore-water pressure acting in the soil mass. Total pressure cells needs to be installed with care to get reasonable measurements. However, measurements are often incompatible with the theoretical predictions such that pressure cell results usually have some inaccuracies. There are several parameters effecting pressure cell errors. However, in the present paper it is only focused on the height of embankment and the duration of dam construction. For this purpose, a case study, namely Alborz embankment dam located in northern part of Iran was studied. It is an earth dam with clay core with a height of 78 m. Using the monitoring data and considering the effect of embankment height and construction period parameters, a model is presented to predict the pressure cells error with Gene Expression Programming (GEP) procedure by GeneXProTools 4.0 software. The computed coefficient of correlation (R2) for the proposed model is 0.98 showing a good agreement with the monitoring data. The obtained results indicate that the ratio of height difference to time difference for Alborz dam has a significant role in dam pressure cells errors
