摘要
针对采用颗粒流模型离散单元法模拟陡高边坡压裂型塔柱状危岩失稳动态演绎过程中危岩体下部劣化区和中上部非劣化区灰岩的细观参数快速准确标定的难点问题,以平行黏结本构模型为颗粒流的接触模型,构建基于正交设计的三维离散元单轴压缩试验,结合重庆市南川区甑子岩第二级陡崖的茅口组灰岩室内试验,通过灰色关联度、多因素方差和回归分析的相互验证,以获得灰岩6个主要细观参数与3个宏观参数之间的定量表达式。研究结果显示:灰岩的弹性模量与颗粒接触模量呈正相关线性增长,泊松比与颗粒刚度比呈对数增长,单轴抗压强度随平行黏结切向强度呈正相关线性增长。进一步构建了宏、细观参数之间的多元函数表达式,并提出灰岩材料细观参数标定流程,算例验证结果显示数值模拟试验结果与室内试验结果破坏模式、应力-应变曲线变化规律一致。所提出的方法可用于灰岩细观参数的快速标定,减少了试错法在细观参数标定过程中的盲目性和繁琐性,为该类压裂座溃型危岩失稳解体的PFC3D数值演绎提供了重要支撑。
The problem of fast and accurate calibration of mesoscale parameters in the lower degraded area and the upper non-degraded area of fractured tower column unstable rock in the process of dynamic calculation of instability of fractured tower column with high slope using particle flow code(PFC)discrete element method is discussed.Taking the parallel bond constitutive model as the contact model of particle flow,a three-dimensional discrete element uniaxial compression test based on orthogonal design was constructed.Combined with the laboratory test of Maokou Formation limestone in the second-order cliffs of the Zengziyan rock,Nanchuan District,Chongqing Municipality,the grey correlation degree,multi-factor variance and regression analysis were mutually verified.The quantitative expressions between six main mesoscopic parameters and three macroscopic parameters of limestone are obtained.The elastic modulus of limestone increased linearly with the contact modulus of particles,and poisson's ratio and the particle stiffness ratio increased logarithmically.The uniaxial compressive strength increases linearly with tangential bond strength,and there are multiple function expressions between macro and meso parameters.Furthermore,the multivariate function expressions between macroscopic and microscopic parameters of limestone materials are constructed.According to this,the calibration process of mesoscale parameters of limestone materials is proposed.The numerical simulation results are consistent with the experimental results in terms of failure mode and stress-strain curve.This method can be used for rapid calibration of the mesoscopic parameters of this limestone,reducing the blind complexity of“trial and error method”in the mesoscopic parameter calibration process,and providing important support for the numerical deduction of PFC for the instability and disintegration of this type of fractured rock.
作者
唐红梅
宋刚
周福川
杨健
TANG Hongmei;SONG Gang;ZHOU Fuchuan;YANG Jian(Institute of Geotechnical Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《重庆师范大学学报（自然科学版）》
CAS
北大核心
2024年第4期50-60,共11页
Journal of Chongqing Normal University:Natural Science
基金
国家自然科学基金面上项目(No.51678097)。
关键词
颗粒流模型
正交设计
宏、细观参数
灰岩
灰关联
particle flow code
orthogonal design
macroscopic and microscopic parameters
limestone
grey correlation
