工程地质学报2024，Vol.32Issue(1)：96-107,12.DOI:10.13544/j.cnki.jeg.2021-0775
水岩循环对变质砂岩微观结构损伤与宏观力学劣化影响机理研究
STUDY ON THE INFLUENCE MECHANISM OF WETTING-DRYING CY-CLES ON METAMORPHIC SANDSTONES MICROSTRUCTURE DAMAGE AND MACROSCOPIC MECHANICAL DETERIORATION
摘要
Abstract
To study the effect of different mineral compositions and microstructures on the weakening of metamor-phic rock macroscopic physical and mechanical parameters during wetting-drying cycles,wetting-drying cycle tests were conducted.The evolution mechanism and mutual relationship of macroscopic physical and mechanical parame-ters with the microscopic mineral composition and structure of metamorphic sandstone were investigated.The results show that the physical and mechanical parameters of the rock decrease with an increase in the number of wetting-dr-ying cycles,and the decrease ratio slows down with an increase in the number of cycles.Uniaxial compressive tests of rock samples after cycling demonstrate that the initial crack compaction phenomenon appears in the stress-strain curve and becomes more obvious with an increase in the number of cycles.The failure characteristics of rock sam-ples change from shear failure to tensile failure with an increase in the cycle numbers.Combined with XRD and SEM tests,the changes in mineral composition and microscopic pore area are statistically analyzed.It is concluded that the hydration and dissolution of chlorite,mica,plagioclase,and the hydration and expansion of microscopic pores are the main reasons for rock damage.Therefore,the concepts of mineral composition degradation degree(Dm)and microstructure degradation degree(Dc)are proposed to quantify rock water-rock cycle microscopic dam-age,and a regression model for the weakening of rock physical and mechanical parameters under the influence of mineral composition and microstructure under the water-rock cycle is established.The proposed model provides a reference for predicting the value of rock physical and mechanical parameters under various wetting-drying cycle numbers.关键词
水岩循环/物理力学参数/微观结构变化/弱化机制/岩石损伤特性Key words
Wetting-drying cycles/Mechanical parameters/Microstructure changes/Weakening mechanism/Rock damage characteristics分类
天文与地球科学引用本文复制引用
曹廷,何刘,王维,顾峰..水岩循环对变质砂岩微观结构损伤与宏观力学劣化影响机理研究[J].工程地质学报,2024,32(1):96-107,12.基金项目
中国电建集团成都勘测设计研究院有限公司科研项目(资助号:P39718).This research is supported by the Scientific Research Project of POWERCHINA Chengdu Engineering Corporation Limited(Grant No.P39718). （资助号:P39718）
