Research on the Prediction Methods of Elastic Modulus of Shale

The elastic modulus of shale is of great significance for various projects. However, shale is a typical transversely isotropic rock, and predicting its elastic modulus is challenging. The commonly used method for predicting the elastic modulus of shale is the Niandou model, but the equation form and parameters determination of this model is complicated. Taking account of the anisotropy of elastic modulus of shale, in this paper a simple linear empirical model was proposed. The results show that the proposed empirical model which can predict the elastic modulus with the change of the bedding angle, is simpler than the classical Niandou model and requires less elastic parameters. For the proposed empirical model, the average relative error between the predicted value and the measured value is slightly smaller. Especially when the angle between the bedding plane and the loading direction is at 15°, 30° and 75°, the accuracy is higher than that of the Niandou model.