宏细观尺度下冻融红砂岩的损伤特性  

Damage characteristics behind freeze-thaw red sandstone at macro and micro scales

作　　者：高红梅 徐立 杨帆 李洪伟 Gao Hongmei;Xu Li;Yang Fan;Li Hongwei(School of Architecture&Civil Engineering,Heilongjiang University of Science&Technology,Harbin 150022,China)

机构地区：[1]黑龙江科技大学建筑工程学院,哈尔滨150022

出　　处：《黑龙江科技大学学报》2025年第2期249-255,共7页Journal of Heilongjiang University of Science And Technology

基　　金：黑龙江省省属高等学校基本科研业务费项目(2023-KYYWF-0533);国家自然科学基金项目(52474218)。

摘　　要：为了研究冻融红砂岩的损伤演化规律,利用单轴压缩试验和CT扫描试验,结合三维重构与损伤理论,从宏、细观两方面研究了冻融红砂岩的损伤演化特征。结果表明:随着冻融过程的深入,红砂岩的单轴抗压强度从42.34 MPa降低到22.86 MPa,弹性模量从11.1 GPa减小为4.06 GPa;提取三维重构冻融红砂岩宏观模型的细观参数,得到红砂岩的平均孔隙半径、孔隙率随着冻融次数的增加而增加;随冻融次数的增加,分形维数由2.29逐渐减小为2.10,冻融15次时分形维数降低幅度最大;红砂岩宏观损伤变量与细观损伤变量重合度较高,从细观变化的角度能够很好地揭示红砂岩宏观的冻融破坏过程。This paper intends to investigate the damage evolution law behind freeze-thaw red sandstone.The achievement is made by using uniaxial compression tests and CT scanning tests,and combining three-dimensional reconstruction and damage theory to study the damage evolution characteristics of freeze-thaw red sandstone from both macro and micro perspectives.The results show that as the freeze-thaw process deepens,the axial compressive strength of red sandstone decreases from 42.34 MPa to 22.86 MPa,and the elastic modulus decreases from 11.1 GPa to 4.06 GPa.Based on the microscopic parameters extracted from a macroscopic model of freeze-thaw red sandstone through 3D reconstruction,the average pore radius and porosity of red sandstone increase with the increase of freeze-thaw cycles.The fractal dimension gradually decreases from 2.29 to 2.10 with the increase of freeze-thaw cycles,and after 15 freeze-thaw cycles,the fractal dimension decreases mostly.There is a bigger overlap between macro damage variables and micro damage variables of red sandstone,indicating that the macro freeze-thaw failure process of red sandstone can be well revealed from the perspective of micro changes.

关 键 词：红砂岩 冻融循环 三维重建 分形维数 损伤变量 

分 类 号：TU45[建筑科学—岩土工程]