# The influence of elastic modulus and compressive strength on the significance of rock failure

## TL;DR

This paper uses simulations to show how rock failure is influenced more by elastic modulus than compressive strength, with smaller elastic modulus variations causing significant rock deformation and failure.

## Contribution

The study reveals that elastic modulus heterogeneity has a greater impact on rock deformation and failure than compressive strength heterogeneity.

## Key findings

- Smaller elastic modulus heterogeneous regions lead to rock failure regardless of model size.
- Elastic modulus has a greater influence on rock deformation and failure than compressive strength.
- Local heterogeneous regions in large models can cause overall failure, while small models require larger heterogeneous areas.

## Abstract

By using numerical simulation methods, the influences of the numerical values of compressive strength and elastic modulus, non-uniformity and the size of heterogeneous regions on the deformation and failure of rocks are analyzed. The research results show that in each group of numerical simulations with different variables, the greater the cumulative acoustic emission (AE) energy, the greater the dilatancy capacity. When the numerical model is destroyed as a whole, the dilatancy capacity rises sharply, and the destruction of the heterogeneous regions of compressive strength and elastic modulus is the reason for the significant increase in the dilatancy capacity of the rock sample. When the overall size of the numerical model is relatively small, the material failure requires a large heterogeneous area of compressive strength, that is, the overall size is the dominant factor. When the overall size of the numerical model is large, a tiny heterogeneous region of compressive strength can lead to overall failure, that is, the local size is the dominant factor. Regardless of whether the numerical model is large or small in size, a smaller elastic modulus heterogeneous region will lead to the failure of the numerical model. The parameters such as the failure mode, dilatancy capacity, AE quantity and AE energy of the numerical model all indicate that under the influence of same external factors, the elastic modulus has a much greater influence on the deformation and failure of rocks than that of the compressive strength.