Evaluation of hydrojacking and hydrofracturing behavior in Aghajari formation (Gotvand dam site foundation), Iran

Regarding the construction of large dams, definition of hydraulically and hydro mechanical conditions of rock mass is necessary. This paper summarizes the results and evaluation of hydraulic jacking and hydraulic fracturing tests conducted in Aghajari formation in different depths. Lugeon testing was carried out in selected boreholes in order to study the groundwater characteristics of the Aghajari formation. The results of sealing grouting and consolidation test grouting have been assessed. Hydro jacking phenomenon has the best performance among the phenomena of Aghajari formation during grouting. In addition, the hydrofracturing pressure especially in first stages has been evaluated. On the basis of these behaviors and their interpretations, appreciable changes have been observed in grouting pressures and designed mixes. However, the changes were considered for optimizing the grouting pressure and water tightness design, as well as the economics.

Hydraulic fractures, SPI, P-Q diagrams, Gotvand Dam, Aghajari formation