Validation of Automated Data Acquisition System (ADAS) of Baixo Sabor dam

Abstract

This paper presents the main characteristics of the automated data acquisition system of Baixo Sabor dam and the quality assessment of ADAS carried out by comparation of automatic and manual measurements. Baixo Sabor is 123 m high concrete arch dam, and 505 m long at the crest, designed, constructed and explored by EDP, located in the northeast of Portugal in Sabor river (a tributary of Douro river). The first filling of its reservoir, with a volume of about 1095 hm3, took place between December 2013 and April 2016. In operation since August 2016, the ADAS of the Baixo Sabor dam allows the measurement of several physical quantities used for the safety control, analysis and interpretation of the dam behaviour, such as: horizontal and vertical displacements, movements of joints, strain, uplift pressure, foundation displacements, seepage, concrete and air temperatures, and reservoir water level, among others. The assessment to the ADAS quality measurements was performed through the analysis of paired samples with manual readings. For this purpose, comparison graphs and statistical values (means, variances, and correlations) of the two sets of quantities were generated. The analysis of this information has shown the existence of deviations from ADAS measurements that were classified into three types: zero scale errors (shift values), sensitivity errors and atypical values. Based on this analysis, the ADAS databases were corrected and a mechanism for filtering anomalous values was implemented. These measures allowed to ensure the correct operation of the ADAS of Baixo Sabor dam.