Problem of monitoring the reliability and safety of operating water-development works

Abstract

1. The monitoring of the condition of water-development works, which is carried out using field observations and investigations will make it possible not only to evaluate the condition of the structures in various stages of construction and service, but also to verify the correctness of the design solutions adopted with respect to the layout of the structures, their construction, and the building technology employed. As practice has demonstrated, design solutions do not always correspond to requirements set forth for the operational reliability of the structures. 2. Results of multiyear field observations and investigations have contributed to improvement of design methods and found reflection in corresponding regulatory-methodical literature. At the same time, there has, up to now, not even been a sufficiently developed procedure with which to determine criteria of the reliable and safe operation of structures. The establishment of these criteria and determination of limiting allowable values of the parameters being monitored should be carried out with allowance for both standard computational requirements, and results of multiyear field observations on the structure. 3. Results of revision to operational-monitoring systems, which can be conducted during scheduled inspections of water-development works, suggest that in the majority of cases, the effectiveness of these systems is inadequate. Unsatisfactory representativeness of field data and a lack of indicators of the condition of the entity being monitored, which are substantiated by proper means—monitoring criteria—are usually basic causes of inadequate effectiveness of operational-monitoring systems. 4. Inadequate representativeness of field data can be explained by both errors in the design of the monitoring system at a given entity, and defects in its implementation, and also by exposure of new monitoring problems during operation, which could not be predicted in the stage of design formulation. That situation where in many cases, the design of monitoring systems is oriented toward the need to confirm only the results of calculations performed under field conditions, and not the models adopted for these calculations also frequently contributes to a reduction in the representativeness of the field data. Support of adequate representativeness of field data where the structure has been in service for an extended time and especially in those cases when the entity was not equipped with embedded monitoring-measuring apparatus that could be restored after failing is a difficult, but very urgent problem,