Dynamic compressive characteristics of a green sandstone under coupled hydraulic-mechanical loading: Experiments and theoretical modeling  

作　　者：Bangbiao Wu Geli Zhao Ying Xu Kaiwen Xia 

机构地区：[1]State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,School of Civil Engineering,Tianjin University,Tianjin,300072,China [2]Yalong River Hydropower Development Company,Ltd.,Chengdu,610065,China [3]Institute of Geosafety,China University of Geosciences(Beijing),Beijing,100083,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2025年第1期126-138,共13页岩石力学与岩土工程学报(英文)

基　　金：the funding support from the National Natural Science Foundation of China(Grant Nos.52079091,42141010,and 42377147).

摘　　要：Deep rock is under a complex geological environment with high geo-stress, high pore pressure, and strong dynamic disturbance. Understanding the dynamic response of rocks under coupled hydraulic-mechanical loading is thus essential in evaluating the stability and safety of subterranean engineering structures. Nevertheless, the constraints in experimental techniques have led to limited prior investigations into the dynamic compression behavior of rocks subjected to simultaneous high in-situ stress and pore pressure conditions. This study utilizes a triaxial split Hopkinson pressure bar (SHPB) system in conjunction with a pore pressure loading cell to conduct dynamic experiments on rocks subjected to hydraulic-mechanical loading. A porous green sandstone (GS) was adopted as the testing rock material. The findings reveal that the dynamic behavior of rock specimens is significantly influenced by multiple factors, including the loading rate, confining stress, and pore pressure. Specifically, the dynamic compressive strength of GS exhibits an increase with higher loading rates and greater confining pressures, while it decreases with elevated pore pressure. Moreover, the classical Ashby-Sammis micromechanical model was augmented to account for dynamic loading and pore pressure considerations. By deducing the connection between crack length and damage evolution, the resulting law of crack expansion rate is related to the strain rate. In addition, the influence of hydraulic factors on the stress intensity factor at the crack tip is introduced. Thereby, a dynamic constitutive model for deep rocks under coupled hydraulic-mechanical loading was established and then validated against the experimental results. Subsequently, the characteristics of introduced parameter for quantifying the water-induced effects were carefully discussed.

关 键 词：Deep rock Split hopkinson pressure bar(SHPB) Compressive behavior Pore pressure Coupled hydraulic-mechanical loading 

分 类 号：TU45[建筑科学—岩土工程]