Research on In Situ Stress Measurement Based on the Combined Method of DIC and Drilling Stress Relief

Existing structural stress is an important parameter for evaluating the current state of a structure. In order to improve the accuracy of in situ stress measurement in the field, this paper proposes an in situ stress measurement method for existing structures, which combines Digital Image Correlation (DIC) technology with the drilling stress relief method. The method utilizes DIC technology to monitor the local displacement or strain caused by stress release from the drilled hole in real time, and further inverts the in situ stress state of the structure based on this data. First, the principle and specific implementation process of the method are introduced. Then, finite element simulations are used to analyze the influence of factors such as size effects, drill hole diameter, drill hole depth, and initial stress magnitude on the measurement results. Finally, experimental validation of the method’s effectiveness is conducted. The results show that the in situ stress measurement method based on the combination of DIC and stress relief has good application effects and prospects in the stress analysis of existing structures. The accuracy and effectiveness of the method are influenced by factors such as specimen size, drill hole diameter, drill hole depth, and stress magnitude. In practical engineering, a comprehensive evaluation should be made, considering the precision of DIC testing and the magnitude of in situ stress, to select appropriate drilling parameters and measurement ranges. During the subsequent stress inversion process, a size calibration factors is applied to adjust the theoretical results, significantly improving the method’s applicability under finite size conditions, and achieving good results. This research provides important references for the stress testing and evaluation of existing structures with finite sizes.