Abstract: The epoxy resin and glue layer of hollow inclusion cell in CSIRO test participate in the transmission of stress and deformation. The regularity results can be used to improve the properties of medium layer or to improve measurement accuracy. In this paper, a calibration procedure of numerical simulation of physical model test is presented. In association with the quantitative expression of geo-stress measurement accuracy, a suitable mathematical model is established. The influence parameters of hollow inclusion’s medium layer on deformation of strain gauge and measurement accuracy is obtained. Results reveal that in the model with single medium, the deformation of axial strain gauge is very small, and the deformations of other strain gauges increase with the rising of elastic modulus (E) or with the declining of Poisson’s ratio (μ) of the medium layer, and vice versa. The variation of E or μ poses an influence smaller than 0.5% on measurement accuracy. On the other hand in the model with double media, when E and μ of glue layer change to be the same with those of rock, the deformation of axial strain gauge increases slightly, while the deformations of other strain gauges continue to reduce, with the value of magnitude-error dropping markedly and angle error rising slightly. The technical transformation of such regularity can be used to improve the measurement accuracy of hollow inclusions.

Key words: geostress, hollow inclusion cell, medium layer, strain gauge, measurement accuracy, single-medium-model, double-medium-model