摘要
三峡库区岸坡岩体劣化的关键在于岩体节理的持续扩展。本文采用分形理论对消落带上下岸坡测窗岩体劣化程度、劣化破碎相变时间及发展趋势进行了分析。研究表明:岩体节理劣化分布具有分形属性,可将缺项值Λ(r)曲线陡缓转折点视为REV(表征单元)岩体尺寸下限;整体来看,劣化使得岩体节理生长向更加均匀、密布的趋势发展,呈现升维特征;进一步利用节理升维值ΔD_(b)建立了劣化程度分级标准,升维值ΔD_(b)与面积节理数增量ΔJ_(ov)、地质强度指标变化值ΔGSI满足指数函数关系;最后探讨并提出了2种节理分维数劣化演变模式,采用岩体劣化破碎相变时间计算式可进行相应的演化预测分析,且岩体劣化破碎相变时间预测是基于割线的估计。由于分维数D_(b)具有较高的统计稳定性,能够满足工程应用需求。研究成果为库区岸坡劣化程度调查以及劣化演化预测提供了新的方法。
The key to the deterioration of bank slope rock mass in the Three Gorges Reservoir area lies in the continuous expansion of rock mass joints.The fractal theory is used to study the deterioration degree,deterioration crushing phase transition time,and development trend of the bank slope measuring window rock mass in the upper and lower drawdown zone.The main conclusions are as follows:the distribution of rock mass joint deterioration has fractal properties,and the steep and gentle turning point of theΛ(r)curve can be regarded as the lower limit of the REV rock mass size.On the whole,deterioration makes the growth of rock mass joints develop to a more uniform and denser trend,showing the characteristics of dimension increase.Further,the deterioration classification standard is established by using the joints fractal dimension increment△Db.Fractal dimension increment value△D_(b),the increment of area joint number△J_(ov),and the variation of geological strength index△GSI satisfy the exponential function relationship.Finally,two joints fractal dimension deterioration evolution modes are proposed.The corresponding evolution prediction and analysis can be carried out by using calculation formula of rock mass deterioration and crushing phase transition time,and the prediction of rock mass deterioration and crushing phase transition time is based on secant estimation.Due to the high statistical stability of fractal dimension D_(b),it can meet the needs of engineering applications.This research provides a new method for the investigation of bank slope deterioration degree and the prediction of deterioration evolution in the Three Gorges Reservoir area.
作者
闫国强
黄波林
殷跃平
胡雷
陈云飞
YAN Guoqiang;HUANG Bolin;YIN Yueping;HU Lei;CHEN Yunfei(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang,Hubei 443002,China;College of Civil Engineering&Architecture,China Three Gorges University,Yichang,Hubei 443002,China;China Institute of Geological Environment Monitoring,Beijing 100081,China)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2023年第7期2399-2407,共9页
Acta Geologica Sinica
基金
国家自然科学基金项目(编号42077234)
重庆市地质灾害防治中心(编号KJ-2021047)联合资助的成果。
关键词
岩体劣化
破碎相变时间
分形理论
演化预测
三峡库区
rock mass deterioration
crushing phase transition time
fractal theory
evolution prediction
Three Gorges Reservoir area
