As bunding is a common control for managing uncontrolled rilling of material at a drawpoint, a bund calculator has been added into the inrush management app. It allows the user to input various measurements for each drawpoint including brow to bullnose distances, brow height, rill angles of the drawpoint material, the amount of overbreak experienced. These then combine with global user defined parameters for bund height, bund rill angle and the amount of space needed for operational reasons to test if the designed bund can fit in the available drawpoint crosscut (in a block caving situation) and determines the location of the bund apex from the brow to manage the volume of material that could rill prior to the brow choking off.

Understanding the relationship between seismic energy and moment parameters.

Why event magnitudes differ between software and how to calculate them.

The excavation hazard is calculated on minodes that represent underground tunnels as a series of connected nodes. For more information on minodes and to find out how to create or update them, go to this page: Minode Generator

You can pick any grid cell to view the frequency magnitude chart of events found in the local area. This is the b-value used for this grid point. The b-value is a very sensitive parameter in hazard calculations, and there are cases where the automatic FM modelling algorithm may not work well. There are several markers to help identify potential areas where the FM model may not represent the data accurately:

Log scales and Gutenberg-Richter distributions.

The Grid-based Analysis application can be used to evaluate the spatial distribution of various seismic parameters. There are a range of source parameter options available, and they can give indications to the rock mass behaviour. Some parameters can be considered as a proxy (stand-in) for rock mass stress, while other parameters can be a proxy for the amount of deformation. There are also parameters available that are associated with the rock mass mechanism or event type.

Grid-based seismic hazard assessment using seismic data for spatial hazard mapping and analysis.

Evaluating the spatial distribution of various seismic parameters.

If you pick a minode in the 3D View, the grid point sources that contribute to the hazard at that minode will be plotted, scaled by how much they contribute. Theoretically, every grid point contributes to the hazard at a minode, but there is an accuracy threshold applied with a minimum probability to speed up the calculations. Increasing the accuracy will result in more contributing grid point sources.

Overview

Probabilistic seismic hazard evaluation based on grid and spatial methods.

Event rate calculations and splattering in grid-based hazard assessment.

Estimating seismic hazard for work areas using excavation view analysis.

The hazard assessment app is designed to be simple to use but beneath the interface is a lot of complexity. It is important to be familiar with the underlying calculations and ensure that you are aware of the assumptions and limitations of the analysis. The calculations have been described in the linked pages below.

There are three types of isosurfaces that can be plotted in the Hazard Isosurfaces window. The details behind the calculation of each parameter is linked in the pages below:

Interpreting hazard isosurfaces and spatial distribution of seismic events.

Grid Definition

Mine Geometry Model Minode Generator is a new utility app which enables you to generate your own new minodes from a mine geometry model. If you're not sure what minodes are or why you would want to generate them, see What are minodes? If you're not sure what mine geometry models are, see Mine Geometry Models Application.

A geotech's guide to understanding moment tensors.

Tools for monitoring drawpoint conditions and inrush events.

Dedicated to analysing blast-related seismicity using Modified Omori Law fitting, cumulative event distributions, and related charts for quantifying decay patterns.

Introduction

Dashboard tools for inrush risk reporting and TARPs.

Physical meaning and calculation methods for seismic energy and moment.

How b-value sensitivity affects seismic hazard calculations and event rates.

Quick reference guide to seismic source parameters and their meanings.

Quantifying effects of input parameter variations on seismic hazard.

Understanding short-term seismic response to triggers and methods for analysing aftershock sequences.

Separating clustered and background seismic events using stochastic methods.

Calculating peak particle velocity from seismic events and ground motion.

You can now plot the relationship in a couple of different ways:

That is the question. An explainer on seismic hazard measurement.

Hazard can be tracked over time by specifying a number of time steps and a step interval. The back analysis tool will step the backdate backward through time and summarise the hazard within each mining volume. Mining volumes can be defined in the Configuration area (link to filter volume editing page). The hazard within each mining volume is calculated by accumulating the hazard within each grid cell or for each minode within the volume.

Framework for monitoring and controlling inrush hazards.

MUL refers to the truncating magnitude of the Gutenberg-Richter distribution