Abstract: In line with the variation characteristics of elastic parameters in the rock mass of fracture developed area, we derived a three-dimensional in-situ stress calculation model with aperture deformation method. Building upon engineering practice and theoretical analysis, we proposed three principles for screening test data to calculate the in-situ stress in fracture developed area. On this basis, we conducted actual project-based three-dimensional in-situ stress measurements. The test results were compared with the stress field characteristics, hydraulic fracturing test data, and topography of the project area, showing relatively consistent outcomes. Furthermore, we analyzed the influence of Poisson’s ratio and elastic modulus deviations on the three-dimensional in-situ stress test data using the full space stereographic projection technology. Results demonstrate that the proposed technique accounts for anisotropy characteristics, and yields reliable calculation results with high engineering practical value. In comparison to Poisson’s ratio, the deviation of elastic modulus significantly affects the magnitude, orientation, and inclination of the in-situ stress.

Key words: in-situ stress, fracture developed area, aperture deformation method, elastic parameter variation, screening principle