Retrofitting load measurement devices on existing anchored structures

Anchored structures are an essential part of infrastructure corridors, as they enable high cuts and the reinforcement of existing structures. As pre-stressed elements, anchors allow for economical construction with low-deformation, making them critical components for ensuring stability. Consequently, comprehensive monitoring is often required alongside inspections, especially when the reliability of the load-bearing elements is in question - e.g., due to creep or corrosion of metallic components. Based on research activities due to the ageing of such structures, several options have been investigated to retrofit load measurement devices to already installed pre-stressed anchors. In addition to different types of coupling methods, this paper presents first results from a trial in which, through the retrofitting of an external thread to strands, a new method for load monitoring is investigated. These methods are particularly useful when information about the current anchor load is lacking, as they provide better insight into the condition of the tension elements and, furthermore, the overall behavior of the structure. The paper shows some approaches already in use and the results of an initial test series, in which the potential of a new approach to amend a load measuring device to an already installed pre-stressed anchor is investigated and validated.