Case Study:

Supply of engineered consolidated barrier seals.

Project Overview

As part of Ulan Underground’s longwall extraction plan, the mine was required to segregate a series of longwall blocks from the next longwall panel. Previously, this meant that an additional gateroad panel was driven and a solid coal barrier was left between goaves.

The Project involved the construction of extra-large barrier pillars to effectively prevent water and atmosphere transfer between goaves after longwall extraction has occurred.

Challenges

The challenged associated with this project were;

• Large water head loads expected (30m)
• The pillars had to withstand double goaf loading while still being effective
• Scheduling the install of the barrier pillars to keep up with longwall retreat rates.
• Ability to install effective seals within the required time frame.

Barrier pillar Ulan No.3 with formwork removed

Solution

Using cutting edge engineering, MPA incorporated the cut-through closure expected in each of the barrier seal locations in the design. The cut-through closure provided a normal force on the seals and therefore mobilised a frictional force to resist the design loads. The result was a cost effective and efficient consolidated barrier seal design.

Results

The installation of these seals removed the necessity of developing an additional gateroad after leaving a solid coal barrier pillar and therefore dramatically eliminating substantial development time and costs regularly incurred by Ulan Underground.