3-D fracture network dynamic simulation based on error analysis in rock mass of dam foundation  

基于误差分析的水电工程坝基岩体三维裂隙网络动态模拟研究（英文）

作　　者：ZHONG Deng-hua WU Han WU Bin-ping ZHANG Yi-chi YUE Pan 钟登华;吴含;吴斌平;张亦弛;岳攀

机构地区：[1]The State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University),Tianjin 300072,China [2]YALONG River Hydropower Development Company,Ltd.,Chengdu 610051,China

出　　处：《Journal of Central South University》2018年第4期919-935,共17页中南大学学报（英文版）

基　　金：Project(51321065)supported by the Innovative Research Groups of the National Natural Science Foundation of China;Project(2013CB035904)supported by the National Basic Research Program of China(973 Program);Project(51439005)supported by the National Natural Science Foundation of China

摘　　要：Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337.大坝坝基岩体裂隙对水电工程坝体安全与稳定的影响巨大,建立准确的坝基岩体三维裂隙网络模型是坝基稳定及灌浆与渗流分析的基础。以往研究多注重对裂隙几何参数(尺寸、产状、位置、密度)的研究,估计方法复杂众多,且大多忽略了各类方法适用性及对参数估计的精度;缺乏研究裂隙模型精度及检验模型准确性的方法。针对上述问题,基于误差分析,以降低模型与实测数据偏差、提升模型准确性为目的,提出基于误差分析的水电工程坝基岩体三维裂隙网络动态建模方法。首先,对4位学者(ODA,KULATILAKE,MAULDON和SONG)提出的体密度估计方法以及另3位学者(EINSTEIN,SONG,TONON)提出的四种裂隙尺寸估计方法的误差进行对比分析,以确定较优的参数估计方法;其次,引入分形维数并基于相对绝对误差建立表征模型与实测数据偏差的误差指标;最后,根据上述成果,构建三维裂隙网络动态建模方法,以最小化误差指标为目标函数,利用下山单纯形法动态调整裂隙体密度及直径参数初始值,修正模型误差指标,最终得到统计意义上符合要求的三维裂隙网络模型。将该方法应用于某水电工程坝基三维裂隙模拟中,结果表明,三维裂隙网络模型精度较高,对实测数据的拟合程度高。

关 键 词：rock mass of dam foundation 3-D fracture network dynamic simulation fractal dimension error analysis relative absolute error(RAE) downhill simplex method 

分 类 号：TV223[水利工程—水工结构工程]