Geotechnical Instrumentation of Embankment Dams

Abstract

The thesis aims at highlighting the importance of geotechnical instrumentation as the tool of dam safety engineers which provides the information necessary to evaluate the performance of embankment dams and gives early warnings of changes that could endanger their safety. It also gives a brief of the requirements of planning an embankment instrumentation system which include defining the objectives of the system and applying the systematic planning approach which contains, among other steps, defining the parameters to be monitored and the selection of the appropriate device or instrument for monitoring and recording data. Data collected form monitoring systems should be properly analyzed by instrumentation engineers which necessitates familiarity with the basic geotechnical concepts related to dam design and engineering. The thesis gives a brief of some these concepts. It is emphasized that the safety of the dam should be maintained throughout its deferent life phases i.e. design phase; construction phase; first filling phase; and operation phase, with some detail of the types of readings to be taken during the last one. A detailed description of the types of instruments used for the monitoring of Roseires Dam Heightening Project (RDHP) and Dam Complex of Upper Atbara Project (DCUAP) is presented to give an idea of how instruments are installed, how readings and measurements are taken and how results are presented as well as an overview of the automatic monitoring system of (RDHP). Instrumentation readings of two example sections from the two projects together with readings of the pressure cells in (RDHP) and seepage observations in (DCUAP) are used to illustrate how instrumentation data are analyzed to come to an evaluation of the safety of the embankments in terms of the different monitored parameters. The thesis is concluded by some recommendations from the author which he believes to be of high importance to be considered.