Geodynamic Research Centre Activities During Construction of the Boguchanskaya HPP

Abstract

The results are presented of the major activities undertaken by the Geodynamic Research Centre during the final stage of Boguchanskaya hydroproject construction.This article presents the progress made by the Geodynamic Research Centre at the Boguchanskaya hydroproject during the final stage of its construction (2006 -2012).As is known, after 1993, the tempo of construction work at the project slowed considerably owing to a lack of funding. The 12-year interruption in construction had an effect on the rocky soil in the dam bed. Therefore, when the decision was made, in 2006, to complete construction of the hydroproject, Institut Gidroproekt was faced with the need, as the general designer, to refine the engineering designs used in the project [1]. In this connection, Geodynamic Research Centre had to update information on the current state of the bed and the portion of the hydraulic engineering installations that had been constructed before the hiatus, as well as to update monitoring observations and carry out numerical calculations of the stress-strain state of the dam bed and its abutments.Considering the complexity and diversity of issues requiring immediate resolution, as well as the significance and great responsibility of the hydroproject under construction, the Centre used all of the forms of surveying and investigation at its disposal, including geodetic, geophysical, geomechanical, seismometric-engineering, seismological-engineering, and calculation methods.Individual results of Centre activities have been published [2 -8], but basically, they are contained in report materials that have been transmitted to the customer and are not available to the broad circle of interested specialists, i.e., hydraulic engineers and surveyors. Therefore, considering the unique nature of the Boguchanskaya hydroproject and the diverse nature of the problems that have arisen during construction, it seems expedient in set forth, in abridged form, the most significant and previously unpublished results of integrated multi-year surveys and investigations. 2 Investigation of Concrete Dam Bed Properties and ConditionOne of the key items concerning surveys at the Boguchanskaya hydroproject, from its very inception, has been determining the deformation and strength properties of the dolerites that underlie the concrete dam bed.As is known, design yield parameters were determined during the survey phase primarily from geophysical data [9], while no experimental determinations were made of shear parameters in the massif or along the "concrete -rock" interface. So, when the task arose of evaluating the current state of the dolerite massif after a long hiatus in dam construction (from 1993 to 2005), so as to be able to refine the design yield and strength characteristics for rock in the facility bed, in 2007 -2008 the Centre undertook integrated (geomagnetic, geophysical, and computational) investigations. At the same time, issues arose of verifying the capability of using the previously used correlation dependence between the static a...