Prediction of Electric Load for Users Based on BP Neural Network

Abstract

Rock masses in underground engineering are generally subjected to complex three-dimensional stress conditions rather than uniaxial loading. Therefore, triaxial compression testing has become a fundamental approach for investigating the strength, deformation, and failure behavior of rocks. In recent decades, extensive studies have been conducted on rock failure laws under triaxial compression, with particular attention to the effects of confining pressure, crack initiation and propagation, damage evolution, and macroscopic failure modes. Existing studies indicate that confining pressure not only increases the peak strength and residual bearing capacity of rocks, but also suppresses tensile crack growth, promotes shear localization, and drives the transition from brittle failure to ductile failure. In addition, the full failure process of rocks under triaxial compression is characterized by distinct stages, including crack closure, elastic deformation, stable crack propagation, unstable crack propagation, and post-peak failure. Acoustic emission monitoring, ultrasonic wave velocity analysis, and energy-based methods have further improved the understanding of progressive rock damage and failure mechanisms. This paper systematically reviews the current research on the strength evolution, deformation characteristics, failure modes, and major controlling factors of rocks under triaxial compression. On this basis, the limitations of existing studies are discussed, especially with respect to fractured rock masses, layered composite rocks, and complex stress paths. Future research directions are also proposed, including multi-method characterization, multi-field coupling analysis, and the integration of laboratory results with engineering-scale applications. This review may provide a useful reference for the study of rock mechanics and the stability evaluation of deep underground engineering.