摘要
白垩系时期的五龙组砂岩,由于其地层年代新,沉积时间较短,岩石内部胶结作用不完全,因此在水化学环境下极易被侵蚀并发生崩解,进而诱发各种灾害。本文以白垩系五龙组砂岩为研究对象,将其置于不同酸碱度的化学溶液中进行岩石的循环崩解试验。通过试验分析了水化学作用下白垩系五龙组砂岩崩解过程中岩石的耐崩解指数;得到每次循环崩解后,各粒径范围内崩解物质量百分比,基于此分析了岩石在水化学环境下的崩解特性;使用微观观察手段和检测手段探究了崩解前后矿物组分变化及崩解过程中岩石的微观结构演变规律;基于热力学以及断裂力学相关理论,构建崩解过程的能量耗散数学模型。研究结果表明:白垩系五龙组砂岩整体崩解速率先增后减并最终趋于稳定,其崩解物粒径分布较集中,主要在0.25 mm以下;在不同水化学环境下,白垩系五龙组砂岩的崩解强度呈现酸性>碱性>中性的差异化特征;将不同崩解循环次数下崩解物颗粒级配分布数据和微观几何结构参数代入能量耗散模型,结合实际情况分析表明岩石崩解能量耗散模型能较好表征岩石的崩解过程。研究成果可为岩石的崩解机制研究提供参考。
The sandstone of the Cretaceous Wulong Formation is highly susceptible to erosion and disintegration in hydrochemical environments due to its young age,relatively short deposition time,and incomplete internal cementation,leading to various disasters.This study focuses on the cyclic disintegration test of the Cretaceous Wulong Formation sandstone in chemical solutions with different acidity and alkalinity.The disintegration resistance index of the rock during the disintegration process under the action of hydrochemistry was analyzed through experiments.After each disintegration cycle,the mass percentage of disintegration in each particle size range was obtained to analyze the disintegration characteristics of the Wulong Formation sandstone in a hydrochemical environment.Microscopic observation and detection methods,including X-ray diffraction and scanning electron microscope tests,were employed to explore changes in mineral components before and after disintegration,as well as the microscopic characteristics of the rock during disintegration.A mathematical model of energy dissipation,reflecting the disintegration process based on thermodynamics and fracture mechanics theories,was constructed.The research results indicate that the overall disintegration rate of the Cretaceous Wulong Formation sandstone increases initially and then decreases,eventually stabilizing.The disintegration intensity of the Wulong Formation sandstone exhibits a differentiated characteristic of acid>alkaline>neutral.The disintegration particle gradation distribution data and micro-geometric structure parameters under different disintegration cycles were incorporated into the energy dissipation model.The analysis demonstrates that the energy dissipation model of rock disintegration can effectively characterize the disintegration process.These findings can serve as a reference for studying the mechanism of rock disintegration.
作者
左清军
朱盛
汤罗圣
吴立
易庆林
李攀
ZUO Qingjun;ZHU Sheng;TANG Luosheng;WU Li;YI Qinglin;LI Pan(National Field Observation and Research Station of Landslides in Three Gorges Reservoir Area of Yangtze River,China Three Gorges University,Yichang 443002,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;Hubei Provincial Communications Planning and Design Institute Co.,Ltd.,Wuhan 430051,China)
出处
《工程地质学报》
CSCD
北大核心
2024年第1期52-63,共12页
Journal of Engineering Geology
基金
国家自然科学基金项目(资助号:41402259)
武汉市重点研发计划项目(资助号:2022012202015024)。
关键词
岩石崩解
能量耗散
水化学环境
干湿循环
Rock disintegration
Energy dissipation
Hydrochemical environment
Dry-wet cycle
