PARAMETRIC STUDY OF DRILLING METHOD PERFORMED ON ONE-WAY POST-TENSIONED SLABS

Determination of the stress state in concrete structures is a very important, but difficult task. In the case of new structures, it is possible to easily instal measurement instruments which can provide important data as a part of real-time monitoring. However, the evaluation of stresses in existing structures is much more challenging. Currently, stress relief methods are a well-established approach for the evaluation of the actual state of existing structures. The so-called Drilling method (also known as Stress-relief coring technique) is one of the possible techniques for such analysis. For practical use of this method, knowledge of pivotal factors which influence stress relief is crucial. Therefore, this paper presents a parametric study performed on a one-way post-tensioned slab which can help to understand the effect of the depth of the core and the distance from the edge of the hole (position of strain gauges) on the change in stress in the vicinity of the drilled core. Finally, based on the obtained data, the recommendations for the subsequent experimental program will be summarized. According to the study, it seems that the depth of drilled core does not significantly influence the stress relief and the main impact can be attributed to distance from the edge of the hole.