工程地质学报2023，Vol.31Issue(6)：1833-1841,9.DOI:10.13544/j.cnki.jeg.2021-0609
冻融循环下粉砂质泥岩强度劣化特性及细观机理研究
STRENGTH DEGRADATION CHARACTERISTICS AND MESO-MECHA-NISM OF SILTY MUDSTONE UNDER FREEZE-THAW CYCLES
摘要
Abstract
This paper aims to investigate the strength degradation characteristic and microscopic mechanism of silty mudstone under freeze-thaw cycles.It carries out the uniaxial compression tests and the mercury intrusion tests on silty mudstone samples under different freeze-thaw cycles.After the uniaxial compression test,the fracture of the rock sample is scanned by SEM.The influence of the number of freeze-thaw cycles on the strength characteristics,failure mode and porosity of the silty mudstone is obtained.The mechanism of strength deterioration of silty mud-stone under freeze-thaw cycles is discussed in depth.The research results show the follows.(1)With the number of freeze-thaw cycles increases,the uniaxial compressive strength and elastic modulus of silty mudstone decrease.The decay rate of uniaxial compressive strength keeps decreasing.The strain increases continuously when the rock sam-ple fails.The decay rate of elastic modulus increases.The failure form of silty mudstone changes from brittleness to plasticity.(2)With the increase of the number of freeze-thaw cycles,the macroporous porosity,the mesoporous po-rosity and the total porosity increase exponentially,and the increase in mesopores is dominated.With the freeze-thaw cycle continues,some of the micropores are transformed into mesopores,and the porosity of the micropores in-creases at first and then decreases.(3)The mechanism of the decrease in uniaxial compressive strength and elastic modulus of silty mudstone under freeze-thaw cycles is as follows.The alternating water-ice phase increases the inter-nal porosity of the rock mass,some of the micropores are connected and transformed into mesopores,resulting in an increase mesoporous porosity.It can be observed that for the silty mudstone under the freeze-thaw cycle,the in-crease in mesoporous porosity is the most important factor leading to the deterioration of its strength.关键词
粉砂质泥岩/冻融循环/强度劣化/细观机理Key words
Silty mudstone/Freeze-thaw cycle/Strength degradation/Meso-mechanism分类
天文与地球科学引用本文复制引用
付宏渊,段鑫波,史振宁..冻融循环下粉砂质泥岩强度劣化特性及细观机理研究[J].工程地质学报,2023,31(6):1833-1841,9.基金项目
国家自然科学基金(资助号:51908069,51838001),长沙理工大学研究生科研创新项目(资助号:CX2020SS06),湖南省自然科学基金项目(资助号:2022JJ40491),湖南省教育厅优秀青年基金(资助号:22B0295).This research is supported by the National Natural Science Foundation of China(Grant Nos.51908069,51838001),Changsha University of Sci-ence and Technology Graduate Research Innovation Project(Grant No.CX2020SS06),National Natural Science Foundation of Hunan Province(Grant No.2022JJ40491)and Excellent Youth Foundation of Education Department of Hunan Province(Grant No.22B0295). （资助号:51908069,51838001）
