A new floor heave mechanism considering the influences of the in-situ stress lateral coefficient and rock tensile strength

Abstract

Floor heave is a disaster that is frequently encountered in tunnel engineering. Existing explanations of floor heave mechanisms have many limitations, and the most important of which is that the stress concentration, release and transfer phenomena and the influences of the in-situ stress lateral coefficient and tensile strength are ignored. Therefore, the combined finite-discrete element method (FDEM) is used to study the failure process of floor rock masses and propose a new mechanical mechanism of floor heave that can consider the influences of the in-situ stress lateral coefficient and tensile strength. The type I fracture energy corresponding to different tensile strengths is calibrated using a direct tensile simulation test. Then, the floor heave mechanism is investigated under different lateral coefficients and tensile strengths, and five different floor heave modes are proposed under different in-situ stress lateral coefficients and tensile strengths. The floor heave modes controlled by the various in-situ stress lateral coefficients and tensile strengths are different, but they can all be explained by the maximum concentrated tangential stress.

Keywords:

• Floor heave
• combined finite-discrete element method (FDEM)
• tensile strength
• in-situ stress lateral coefficient
• stress concentration

Acknowledgments

The work in this paper was based on the Y-Code of Munjiza et al. and the Y-Geo and Y-GUI of Grasselli’s Geomechanics Group (http://www.geogroup.utoronto.ca/).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (42107171, 41941018 and U21A20153).