Displacements study of a dam using low-cost GNSS receivers, high precision leveling and Finite Element Model

Emerging low-cost Global Navigation Satellite System (GNSS) receivers are gaining prominence in geosciences and surveying engineering, finding application in diverse positioning research endeavors. The primary aim of this study was to assess the structural integrity using low-cost GNSS technology, whose usability has advanced significantly. The fundamental premise of the research is the assumption that the lifespan of the dam has reached its end in accordance with international regulations. Over a span of four years and across multiple campaigns, a combination of low-cost GNSS, high precision leveling data, and Finite Element Modeling techniques were employed to monitor deformations at the Sanalona dam. A notable deformation was identified at the central curtain of the dam. Utilizing low-cost GNSS equipment, horizontal deformations of up to 10 cm and vertical deformations of up to 30 cm were recorded. These values do not jeopardize the operational objectives of the dam as per the stipulations of the U.S. Army Corps of Engineers (USACE). The Sanalona Dam continues to operate effectively within the bounds of international regulations, even when subjected to extraordinary phenomena. The findings of this study hold relevance for the wider adoption of low-cost GNSS equipment in civil engineering structures and other demanding geodetic applications, including historic infrastructures. Moreover, the study underscores the viability of conducting precise dam surveys utilizing low-cost GNSS devices in campaign mode.