Elaho River Environmentally Sensitive Blasting
Scope of the Project
- Drilling and blasting using Nxburst Rock Breaking Cartridges
- Remove rock obstruction to allow for fish to migrate upstream
A rock located in the Elaho River needed to be broken into fridge sized pieces before winter when the water levels of stream rises. As the water level rises and the river becomes more aggressive, the broken rock will be washed down the stream from the force of the water. Nxburst was used as an environmentally sensitive and friendly alternative to traditional explosives. The detonation of conventional explosives in or near fish habitat has been demonstrated to cause disturbance, injury and/or death to fish and marine mammals, and/or the harmful alternation, and disruption or destruction of their habitats. 18’ – 20’ holes were drilled on average with 3 – 5 Nxburst cartridges decked in each borehole with 1.5m – 2m of spacing between each hole. Weaker and incompetent zones of the rock to be blasted were efficiently stemmed to reduce blast overpressure, control flyrock and increase fragmentation.
Which GeoBreak Products Were Recommended
Nxburst 50060 charge weights were recommended for this rock obstruction. 500 grams of propellant for the 60mm cartridge for 64mm size borehole.
The expected outcome of using Nxburst was to blast the rock obstruction to the desired fragmentation to allow for the river to wash away the rock during peak rain season.
In 3 separate blasts, Nxburst was used to blast the rock in a controlled fashion without the use the use of a destructive shockwave not disruption to fish habitats, producing by-products from the detonation of conventional explosives and not disrupting the integrity of the rock from the adjacent cliff or logging road.
Final Thoughts From The Project Contractors
The use of Nxburst allows those without blasting experience to provide a blasting service with minimal transportation and storage requirements because of its 1.4s classification (same classification as small arms ammunition). While providing geotechnical solutions related to meshing, drilling and scaling, having a crew that are Nxburst certified blasters adds an added service for projects where there are drilling/blasting in the scope of the work. Similar to Seymour River, an environmentally sensitive approach was used to blast the rock in the Elaho River. Being Nxburst certified creates the opportunity to bid on jobs where there are drilling and blasting work in remote areas where the expertise and background of rope access technicians proves to be beneficial.