首页|基于耗散能的砂岩三轴压缩损伤破坏演化阶段划分及特征分析

基于耗散能的砂岩三轴压缩损伤破坏演化阶段划分及特征分析

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采用MTS816 岩石力学测试系统开展常规三轴压缩试验,分析粉砂岩力学性能及能量演化规律.对应力-应变曲线分别积分计算出砂岩三轴压缩下的弹性能密度、耗散能密度与输入能密度,分析三者随围压增加的规律,并基于耗散能理论进行演化阶段划分及应力特征分析.结果表明:砂岩的峰值应力、峰值3 种能量密度和裂纹扩展能耗比与围压呈现出较强的正线性关系;在围压10、15 MPa下岩石闭合应力水平归零,起裂应力水平呈现下降趋势,岩石压密阶段消失,直接进入弹性阶段,导致岩石出现起裂应力增长放缓、弹性阶段缩短和塑性阶段增长现象;起裂应力放缓并没有影响砂岩峰值应力和裂纹扩展能耗比随围压增长趋势.
Classification and Characteristic Analysis of Damage Evolution Stages of Triaxial Compression of Sandstone Based on Dissipated Energy
MTS816 rock mechanics testing system is used to carry out conventional triaxial compression experi-ments to analyze the mechanical properties and energy evolution law of siltstone.The stress-strain curves are inte-grated to calculate the elastic energy density,dissipated energy density and input energy density of sandstone un-der triaxial compression,analyze the law of the increase of the three with peripheral pressure.Based on the dissi-pated energy theory,the evolution stage is divided and the stress characteristics are analyzed.The results show that the peak stress,the three kinds of peak energy density and the energy consumption ratio of crack extension of sandstone show a strong positive linear relationship with the peripheral pressure;under the peripheral pressure of at 10MPa and 15MPa,the rock closure stress level goes to zero,the crack initiation stress level shows a decrea-sing trend,the rock compression stage disappears,and the rock directly enters the elastic stage,which leads to a slowdown in the growth of crack initiation stress,shortening of the elastic stage,and growth of the plastic stage;the slowdown in the crack initiation stress has no effect on the growth of the peak stress and the crack extension energy consumption ratio of the sandstones with the peripheral pressure.

rock mechanicssandstoneenergy evolutioncharacteristic stress

倪双喜、刘洋、谈坤、杨语翔、倪良波

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安徽建筑大学 建筑结构与地下工程安徽省重点实验室,安徽 合肥 230000

岩石力学 砂岩 能量演化 特征应力

安徽省自然科学基金安徽省高校优秀拔尖人才培育资助项目国家自然科学基金

2108085ME192gxyq202003351604006

2024

兰州工业学院学报
兰州工业学院

兰州工业学院学报

影响因子:0.205
ISSN:1009-2269
年,卷(期):2024.31(1)
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