A Rough Discrete Fracture Network Model for Geometrical Modeling of Jointed Rock Masses and the Anisotropic Behaviour

Peitao Wang,Meifeng Cai,Zhenwu Qi,Cao Liu,Zhichao Liu

doi:10.3390/app12031720

Peitao Wang, Meifeng Cai + Show 3 more

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https://doi.org/10.3390/app12031720

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Abstract

The geometry of the joint determines the mechanical properties of the rock mass and is one of the key factors affecting the failure mode of surrounding rock masses. In this paper, a new rough discrete fractures network (RDFN) characterization method based on the Fourier transform method was proposed. The unified characterization of the complex geometric fracture network was achieved by changing the different Fourier series values, which further improved the characterization method of the RDFN model. A discrete element numerical calculation model of the complex RDFN model was established by combining MATLAB with PFC code. Numerical simulation of the anisotropic mechanical properties was performed for the RDFN model with a complex joint network. Based on the results, the geometry of the joint network has a significant influence on the strength and failure patterns of jointed rock masses. The failure modes of the opening are highly affected by the orientation of the fracture sets. The existence of the rough fracture sets could influence the failure area of different excavation situations. The study findings provide a new characterization method for the RDFN model and a new characterization approach for stability analysis of complex jointed rock masses.

Highlights

The structural planes, which are randomly distributed in nature, are important factors dominating the mechanical properties of jointed rock masses
Many scholars have carried out several studies on mechanical behaviours using the discrete fracture network (DFN) model
The failure modes of the opening are highly affected by the orientation of the fracture sets

Summary

Introduction

The structural planes, which are randomly distributed in nature, are important factors dominating the mechanical properties of jointed rock masses. Multiple structural planes intersect each other and cut the complete rock mass into multiple parts, affecting the mechanical properties and inducing significant anisotropy in the rock mass [1,2,3,4,5,6,7,8]. To analyse the rock mechanics problems with different geometric forms of complex joints and the spatial distribution of complex joints, related simulation studies on the complex joint network model of jointed rock masses have been gradually carried out. Wang et al [9] employed the DFN model to quantitatively analyse the permeability tensor characteristics and the directional characteristics of rock mass seepage under different geometric distributions of jointed rock masses. Wang et al [10]

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