Open Cut » Overburden Removal
This project aimed to research, develop and implement a design methodology to automate the design of a complete, multi-pass dragline strip. The design methodology was implemented by extending the capabilities of the 3d-Dig dragline simulation system.
The 3d-Dig system has been enhanced to include the following components and capabilities:
· The design of individual dragline Steps including excavation shape, dragline positioning over a range of dig positions and dragline dumping over a range of dump positions.
· The design of a range of dump types and flexible dumping strategies.
· Assembly of a range of dragline Steps to form a complete Procedure for the excavation of a complete Block.
· Assembly of Procedures over a range of Blocks to excavate a complete Sub Pass.
· Assembly of a sequence of Sub Passes to perform the complete excavation of a Pass within a Pit.
· Assembly of a sequence of Passes to perform the complete excavation of a multipass pit.
The enhanced 3d-Dig is currently capable of modelling a suitably configured multipass dragline operation and the primary objectives have been met. The original proposal detailed an iterative excavation and dump adjustment function. This was intended to automatically adjust the width of an extended key cut to build a specified bench. This functionality has not been implemented however the systems capability to excavate only the required material from a given dragline step and the flexibility provided on the dump side by the Dump Hierarchy system has proved capable of achieving the same end.
Before commencing this project a study was done over a range of mines to determine the typical operating methods and operating method components that the system will be required to automate. As a result, one particular multi-pass example was selected as it contained all of the necessary operating methods .The system is currently capable of modelling this operation with predetermined excavation shapes. We are confident the system for auto adjustment of excavations and dumps will successfully perform this task over a wide range of operating methods.
The original specification for the system was to effectively model the dragline behaviour in steady-state areas of the pit with ramps and end walls being modelled in an approximate manner by the system or manually by the user. The system has however demonstrated significant capability to handle non-steady-state digging conditions. The dumping methodology allows for the selection of dumps within the draglines reach but beyond the current block in both advanced and arrears direction. The second of the two worked examples in this report shows a complete operation between an end wall and a centrally located perpendicular coal access ramp. The automated dragline simulation successfully splits the ramp moving material along pit and completes the end wall.
An 
e-newsletter has also been published for this project, highlighting its significance for the industry.