Dijkmonitoring

Abstract

With the experiment All-in-one Sensor Validation Test the IJkdijk Foundation wishes to gain more insight into the functionality and performance of levee monitoring systems. By monitoring levees dike managers gain more insight into what is happening in and around the levee. This also allows making real-time predictions with regard to the strength of the levee on the basis of innovative dike monitoring systems. In an experimental setting, the functionality of the real-time tracking and predicting of levee strength was demonstrated. In addition, there was the desire to value and compare levee monitoring systems. Key components of monitoring systems are measurement techniques and visualization systems. Nine measurement techniques and three visualization systems are reviewed. In order to get a validated review system an assessment framework was prepared. The assessment framework consisted of a set of relevant criteria for measurement and visualization systems. To value the measurement and visualization systems an experiment was designed. The basis for the experiment consisted of three test levees, scale 1:1. Two test levees were similar in structure: a clay/sand levee on a sand surface. The other test levee consisted of sand with a clay cover on weak subsoil. The construction of the test levees was comparable with levees in practice. In and around the test levees measurement techniques were installed. Project participants determined, depending on the capabilities of their measurement techniques, in which test levee(s) they installed their measurement techniques. The test levees were loaded in an artificially way during one week. In this week the test levees could fail in one of the following failure mechanisms: piping, micro-instability, macro-instability and erosion due to overtopping. For participants it was unknown when and which failure mechanism the test levees would fail. During the experiments, data was collected on amongst others water pressures, temperature and inclination. Data (numerical, maps en photos) were collected and transported to a database using the purpose build network. Data acquisition took place through the AnySense Connect system. Visualization parties took data from this database and presented these data and made on the basis of observations and calculations, predictions about when a certain failure mechanism could occur. The predictions made by the participants during the experiment were collected by the test supervisors and used for the final assessment. It appeared that integration of measurement techniques, analysis models and visualization systems led to the best prediction of the dike strength. After the experiment, according to the assessment framework, the measurement and visualization systems were assessed and validated by an evaluation committee consisting of people with different expertise within the field of levee management. Levee managers are provided with an overview of the performance of different measurement techniques and visualization systems within the All-in-one Sensor Validation Test. With this overview one is able to determine which measurement technique or visualization system suits best their own practical situation and specific needs.