冻融红砂岩的微观孔隙结构与损伤特征
Microscopic pore structure and damage characteristics behind freeze-thaw red sandstone
兰永伟 1高宏伟 2刘朋飞 3张恒4
作者信息
- 1. 黑龙江科技大学 矿业工程学院,哈尔滨 150022
- 2. 晋能控股装备制造集团长平公司,山西 晋城 048004
- 3. 宁夏红墩子煤业有限公司,宁夏 银川 750000
- 4. 黑龙江科技大学 建筑工程学院,哈尔滨 150022
- 折叠
摘要
为研究冻融作用下红砂岩微观孔隙结构和损伤特征,采用冻融循环试验、压汞试验和数值模拟等方法,研究了冻融红砂岩的孔容、孔隙度、冻胀应力的变化规律,以冻胀应力、孔隙度为参数,获得了冻融红砂岩的宏、细观损伤特征.结果表明:随着冻融次数增加,红砂岩试件两端矿物颗粒脱落现象明显,中间部位损伤逐渐增大,试件内部孔隙不断演化和扩展,大孔孔容增大明显,孔隙度与冻融次数之间呈指数函数关系;随着冻融次数增加,红砂岩的冻胀应力不断增加,冻胀应力与冻融次数之间服从三次多项式关系,两端冻胀应力分布范围逐渐扩大,冻融损伤是从两端开始,逐渐延伸至中部区域,与冻融后的表观损伤结果基本一致;随着冻融次数增加,红砂岩宏、细观损伤变量不断增加,宏、细观损伤变量变化规律基本一致.
Abstract
This paper intends to investigate the microscopic pore structure and damage characteristics behind red sandstone under freeze-thaw action.By using freeze-thaw cycle test,mercury injection test and numerical simulation,the study explores the variation laws behind pore volume,porosity and frost heave stress on the freeze-thaw red sandston,and obtains the macro and micro damage characteristics behind freeze-thaw red sandstone by using the frost heave stress and porosity as parameters.The results show that with the increase of the freeze-thaw times,the mineral particles at both ends of the red sandstone speci-men fall off apparently,the damage in the middle part increases gradually,the internal porosity of the specimen evolves and expands continuesly with the increase of the pore volume of large pores,and the ex-ponential function relationship exists between porosity and freeze-thaw times;with the increase of freeze-thaw times,the frost heave stress of red sandstone increasse continuesly,and the relationship between frost heave stress and the freeze-thaw times follows a cubic polynomial relationship.The distribution range of the frost heave stress at both ends gradually expands,and the freeze-thaw damage starts from both ends and then extends to the middle region,as which is basically consistent with the apparent damage results after freeze-thaw.With the increase of freeze-thaw times,the macro and micro damage variables of red sandstone continue to increase,and basically consistent with the change law.
关键词
冻融循环/微观孔隙结构/孔隙度/表观损伤/热应力Key words
freezing-thawing cycle/microscopic pore structure/porosity/apparent damage/thermal stress引用本文复制引用
基金项目
黑龙江省省属高等学校基本科研业务费项目(2023-KYYWF-0533)
出版年
2024
国家科技期刊平台
NSTL
万方数据