首页|真三轴应力条件下冻结钙质黏土能量特征及影响因素分析

真三轴应力条件下冻结钙质黏土能量特征及影响因素分析

扫码查看
原文链接
  • 万方数据
  • 维普
为深入探讨在真三轴应力路径及多因素交互作用条件下冻结钙质黏土的能量特征及其影响程度，本研究借助ZSZ-2000型真三轴冻土试验平台，采用正交试验的设计方法，开展冻结钙质黏土真三轴压缩试验研究。研究结果揭示:在初始压密阶段及线弹性阶段，冻结钙质黏土的输入能相对较低，增长速率缓慢;随着加载过程的深入，输入能逐步增加，其增长速率亦随之提高;至破坏阶段，输入能-等效应力曲线呈现出明显的跃升特征，此时输入能的急剧上升，说明输入能曲线斜率的变化是冻结钙质黏土内部裂纹非稳定发展的微观表现。同时，输入能曲线的突然急升亦指示了失稳破坏的发生。进一步通过极差分析及AHP层次分析可得一致的输入能影响因素优劣次序:含水率w、中主应力系数b、温度T、含盐量φ、围压σ3。含水率对输入能的负向影响显著，温度和中主应力系数b对输入能有着显著的正向影响关系，随着中主应力系数b值的增加，其对冻结试样输入能的影响程度呈减弱的趋势且存在一个最优中主应力系数b=0。33使试样输入能增幅达到最大。
Energy characteristics and influencing factors of frozen calcareous clay under true triaxial stress
In order to deeply explore the energy characteristics of frozen calcareous clay and the degree of its in-fluence under the conditions of true triaxial stress path and multi-factor interaction,this study carries out the re-search of true triaxial compression test of frozen calcareous clay with the help of ZSZ-2000 true triaxial perma-frost test platform by adopting the design method of orthogonal test. The results show that the input energy of frozen calcareous clay is relatively low and the growth rate is slow in the initial compaction and linear elasticity stages;as the loading process progresses,the input energy gradually increases and so does the growth rate;At the damage stage,the input energy-equivalent stress curve shows an obvious jumping feature,and the sharp in-crease in input energy at this time indicates that the change in slope of the input energy curve is a microscopic manifestation of the unsteady development of cracks within the frozen calcareous clay. At the same time,the sudden sharp rise of the input energy curve also indicates the occurrence of instability damage. The damage curve characteristics of frozen clay are consistent with the characterization of the input energy curve,and it is rea-sonable to use the input energy to characterize the strength of frozen soil samples. Further analysis of extreme variance and hierarchical AHP analysis leads to a consistent order of superiority of the input energy influences:water content ω,mean principal stress coefficient b,temperature T,salinity φ,and circumferential pressure σ3. The moisture content has a significant negative effect on the input energy,the temperature and the mean princi-pal stress coefficient (MPSC) b have a significant positive effect on the input energy,and as the value of MPSC b increases,its effect on the input energy of the frozen specimens tends to decrease,and there is an optimum MPSC b=0.33 to maximize the increase in the input energy of the specimens. It is proposed to use the damage input energy to characterize the strength of permafrost,which provides an intuitive and comprehensive measure of the damage characteristics of permafrost by quantifying the total amount of energy absorbed by permafrost be-fore reaching the damage state. By analyzing the damage input energy,the energy absorption and dissipation mechanism of permafrost in the stress process can be better understood,which is of practical significance for guiding the construction of permafrost projects and promoting the development of theories and models of perma-frost mechanics.

saline frozen soiltrue triaxialstress pathenergy characteristicsimpact analysisAHP hierarchical analysis

曹祎、荣传新、王彬、施鑫、王志、张杰

展开 >

深地工程智能建造与健康运维全国重点实验室,江苏徐州 221116

安徽理工大学土木建筑学院,安徽淮南 232001

河南理工大学河南省地下工程与灾变防控重点实验室,河南焦作 454000

安徽水利水电职业技术学院建筑工程学院,安徽合肥 231603

展开 >

盐渍冻土 真三轴 应力路径 能量特征 影响分析 AHP层次分析

国家自然科学基金项目江苏省研究生科研与实践创新计划项目河南省地下工程与灾变防控重点实验室开放研究基金项目安徽省博士后科学基金项目中国矿业大学研究生创新计划项目

51878005KYCX24_2818KFKT 2023-062022B6352024WLKXJ197

2024

10.7522/j.issn.1000-0240.2024.0102

冰川冻土
中国地理学会 中国科学院寒区旱区环境与工程研究所

冰川冻土

CSTPCD
影响因子：2.546
ISSN：1000-0240
年,卷(期)：2024.46(4)