Research on Mechanical Properties and Deformation-Fracture Energy Consumption Characteristics of Plateau Frozen Rocks

TL;DR

This study investigates how low temperatures and moisture affect the mechanical properties, deformation, fracture behavior, and energy consumption of plateau frozen rocks, providing insights for safer and more efficient resource extraction.

Contribution

It offers a comprehensive analysis of frozen sandstone's mechanical and energy characteristics under temperature and moisture effects, integrating experimental and numerical methods.

Findings

Freezing increases sandstone strength and brittleness.

Porosity of sandstone increases by 63.15% with decreasing temperature.

Frozen rocks absorb more energy during deformation than at room temperature.

Abstract

The exploitation of mineral resources in plateau regions is confronted with critical challenges including low blasting efficiency, excessive energy consumption,and compromised operational safety when dealing with low-temperature water-bearing frozen rock masses.This study systematically investigates the dynamic-static mechanical properties,deformation-fracture behaviors,and energy consumption characteristics of plateau frozen sandstone under the coupled effects of temperature and moisture content (5%-15%).The research methodology integrates field sampling, low-pressure low-temperature simulation tests, graded impact loading tests, and numerical inversion analysis. Results demonstrate that freezing significantly enhances the dynamic strength and brittleness of saturated sandstone.The pore structure undergoes substantial evolution with decreasing temperature, with the porosity increasing by 63.15%.Based on PFC3D microscopic simulations, the mechanism of frost heave damage and the regulatory effect of water-ice phase transition on rock mechanical behaviors are elucidated.A quantitative analysis method for energy dissipation is proposed, revealing that the energy absorption increment of frozen rocks is higher than that of room-temperature samples.The findings provide a theoretical basis and technical support for optimizing blasting parameters, realizing directional energy release,and promoting green construction of frozen rock masses in high-altitude areas.