This is generally related to the water table being above the toe or to perched water tables. The water does not accumulate resulting in standing water, there is a discharge path.
The main issue with wet walls is that they difficult to identify. The only way is for the blast crew to examine the dip rope after each hole and check if the tape is wet above any identified standing water. Consequently the dip rope must be dried (usually by dragging in dust) before each hole.
Where non-water-resistant explosives are loaded it is essential to identify wet walls to prevent product erosion and slumping.
Wet walls are measured from the toe of the hole to the highest wet area. Note that wet walls can not be less than standing water.
Example. The blast crew member records a 30m hole with 2m standing water but notices the tape is wet on the bottom 5m. This hole has 5m wet wall.
With Warning Explosion
These units of competency are recommended for current Drill and Blast Engineers, Superintendents, Supervisors and Senior Shotfirers wishing to increase both their design and management skills.
Course assessment is by completion of classroom and online components and by assignment submission.
Class size is limited to eight persons on a first come basis.
Course leader is Peter Duniam BE. MPM. Director of Blast Management International with over thirty years industry experience.
5 DAY COURSE
MAY 11-15, 2020
$2,900 per person includes lunch each day, 500 page colour manual and statement of attainment for the completed competencies.
ENQUIRIES & BOOKINGS
Phone (07) 3348 5144
0409 001 186
Note this class is not suitable for persons without comprehensive drill and blast experience in either an engineering or operational role.