ABSTRACT
The monitoring of embankment behaviour means, measurements made, directly or indirectly, by instruments installed, or by visual inspections. Thus, monitoring will cover all stages: at construction, during first filling, and subsequently during operation, particularly in sudden drawdown conditions. This entails measurements at greater frequency for a shorter foreseeable future, during construction and first filling and at less frequently for a long-term behaviour during operation. These measurements exclude monitoring needed at an unplanned stage due to unforseen changes in environment caused by seismic activity or unusual floods. This clearly makes a distinction between the instruments used for short- and long-term monitoring, particularly with respect to durability, simplicity and practical convenience of measurements. It is difficult to lay down a rigid approach for monitoring, at different stages, as design and construction methods influence instrumentation and consequently measurement methods. Every dam becomes unique, even if the design, construction and instrumentation methods remain unchanged and the embankment is placed in different environmental conditions, natural, social or political. Dam designs are normally based on previous experiences with problems and their solutions, but this does not diminish the importance of instrumentation and monitoring of performance of new dams, as interaction with environment may be different.
