Discontinuity development patterns and the challenges for 3D discrete fracture network modeling on complicated exposed rock surfaces  

作　　者：Wen Zhang Ming Wei Ying Zhang Tengyue Li Qing Wang Chen Cao Chun Zhu Zhengwei Li Zhenbang Nie Shuonan Wang Han Yin 

机构地区：[1]College of Construction Engineering,Jilin University,Changchun,130026,China [2]Liaoning Nonferrous Geological Exploration and Research Institute Co.,Shenyang,110013,China [3]School of Earth Sciences and Engineering,Hohai University,Nanjing,210098,China [4]Northeastern University,Shenyang,110819,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第6期2154-2171,共18页岩石力学与岩土工程学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2022YFC3080200);the National Natural Science Foundation of China(Grant No.42022053);the China Postdoctoral Science Foundation(Grant No.2023M731264).

摘　　要：Natural slopes usually display complicated exposed rock surfaces that are characterized by complex and substantial terrain undulation and ubiquitous undesirable phenomena such as vegetation cover and rockfalls.This study presents a systematic outcrop research of fracture pattern variations in a complicated rock slope,and the qualitative and quantitative study of the complex phenomena impact on threedimensional(3D)discrete fracture network(DFN)modeling.As the studies of the outcrop fracture pattern have been so far focused on local variations,thus,we put forward a statistical analysis of global variations.The entire outcrop is partitioned into several subzones,and the subzone-scale variability of fracture geometric properties is analyzed(including the orientation,the density,and the trace length).The results reveal significant variations in fracture characteristics(such as the concentrative degree,the average orientation,the density,and the trace length)among different subzones.Moreover,the density of fracture sets,which is approximately parallel to the slope surface,exhibits a notably higher value compared to other fracture sets across all subzones.To improve the accuracy of the DFN modeling,the effects of three common phenomena resulting from vegetation and rockfalls are qualitatively analyzed and the corresponding quantitative data processing solutions are proposed.Subsequently,the 3D fracture geometric parameters are determined for different areas of the high-steep rock slope in terms of the subzone dimensions.The results show significant variations in the same set of 3D fracture parameters across different regions with density differing by up to tenfold and mean trace length exhibiting differences of 3e4 times.The study results present precise geological structural information,improve modeling accuracy,and provide practical solutions for addressing complex outcrop issues.

关 键 词：Complicated exposed rock surfaces Discontinuity characteristic variation Three-dimensional discrete fracture network modeling Outcrop study Vegetation cover and rockfalls 

分 类 号：TU45[建筑科学—岩土工程]