Rock Joint Surfaces Measurement and Analysis of Aperture Distribution under Different Normal and Shear Loading Using GIS

TL;DR

This study introduces a GIS-based method for analyzing rock joint aperture distribution, revealing how normal and shear loads affect joint matching and aperture characteristics.

Contribution

A novel approach using GIS to measure and analyze 3D surface characteristics and aperture distribution of rock joints under different loading conditions.

Findings

Normal load reduces aperture frequency, indicating better joint matching.

Shear displacement increases aperture, indicating surface unmatching.

Aperture distribution changes are visualized and interpreted under various loads.

Abstract

Geometry of the rock joint is a governing factor for joint mechanical and hydraulic behavior. A new method of evaluating aperture distribution based on measurement of joint surfaces and three dimensional characteristics of each surface is developed. Artificial joint of granite surfaces are measured,processed, analyzed and three dimensional approaches are carried out for surface characterization. Parameters such as asperity's heights, slope angles, and aspects distribution at micro scale,local concentration of elements and their spatial localization at local scale are determined by Geographic Information System (GIS). Changes of aperture distribution at different normal stresses and various shear displacements are visualized and interpreted. Increasing normal load causes negative changes in aperture frequency distribution which indicates high joint matching. However, increasing shear displacement causes a rapid increase in the aperture and positive changes in the aperture frequency distribution which could be due to unmatching, surface anisotropy and spatial localization of contact points with proceeding shear.