摘要
开展了不同围压下软岩和硬岩两种堆石料的室内三轴试验,并对得到的邓肯-张和南水模型参数进行分析,发现不同岩性的两种堆石料均在低围压时表现为应变软化和剪胀特性,高围压时表现为应变硬化和剪缩特性;邓肯-张和南水模型在不同岩性堆石料的剪切强度、弹性模量和体变模量反映上均有差异,模型试验参数均可用于堆石坝的应力、应变计算分析。邓肯-张模型表达式和参数的拟合方法均比较简单、直观,参数的物理概念明确,虽易于被工程师接受和应用,但不能反映堆石料的剪胀特性;南水模型的剪切强度和弹性模量参数取值与邓肯-张模型一致,但在体变模量参数上与邓肯-张模型有别,能更为准确地反映堆石料剪胀特性。另外还发现,采用不同围压三轴试验结果整理得到的模型参数存在明显差异,低围压下三轴试验获得的模型参数用来预测高堆石坝变形得出的结果偏小。从工程安全的角度出发,建议采用高围压下堆石料三轴试验得到的模型参数来预测高堆石坝变形。
In this paper,the indoor triaxial tests of soft rock and hard rock rockfill under different confining pressures are carried out,and the parameters of Duncan-Zhang and Shen Zhujiang models are analyzed.It is found that the two rockfill materials with different lithologies exhibit strain softening and dilatancy characteristics under low confining pressure,and strain hardening and shear shrinkage characteristics under high confining pressure.Duncan-Zhang and Shen Zhujiang models have differences in the reflection of shear strength,elastic modulus and bulk modulus of rockfill materials with different lithology.The model test parameters can be used for the calculation and analysis of stress and strain of rockfill dams.The Duncan-Zhang model expressions and parameter fitting methods are relatively simple and intuitive,and the physical concepts of the parameters are clear.Although it is easy to be accepted and applied by engineers,it cannot reflect the dilatancy characteristics of rockfill materials.The values of the shear strength and elastic modulus parameters of the Shen Zhujiang model are consistent with the Duncan-Zhang model,but are different from the Duncan-Zhang model in terms of bulk modulus parameters,which can more accurately reflect the dilatancy characteristics of rockfill materials.In addition,it is also found that there are significant differences in the model parameters obtained from the triaxial test results of different confining pressures.The model parameters obtained from the triaxial test under low confining pressure are used to predict the deformation of the high rockfill dam and the result is too small.From the perspective of engineering safety,it is recommended to use model parameters obtained from triaxial tests of rockfill materials under high confining pressure to predict the deformation of high rockfill dams.
作者
石北啸
吴鑫磊
常伟坤
SHI Beixiao;WU Xinlei;CHANG Weikun(Key Laboratory of Reservoir&Dam Safety of the Ministry of Water Resources,Nanjing 210024,China;Geotechnical Engineering Department of Nanjing Hydraulic Research Institute,Nanjing 210029,China;School of Water Conservancy and Hydroelectric Power,Hebei University of Engineering,Handan 056038,China)
出处
《华北水利水电大学学报（自然科学版）》
北大核心
2021年第4期70-76,共7页
Journal of North China University of Water Resources and Electric Power：Natural Science Edition
基金
国家重点研发计划项目(2018YFC1508502)
国家自然科学基金项目(51679149,51779152)
江西省水利厅重大科技项目(202124ZDKT06)。
关键词
堆石坝
三轴试验
邓肯-张模型
南水模型
模型参数
rockfill dam
triaxial test
Duncan-Zhang model
Shen Zhujiang model
model parameter
作者简介
石北啸(1976-),男,教授级高级工程师,博士后,从事粗颗粒料力学试验与土石坝安全方面的研究。E-mail:shibeixiao@nhri.cn。
