Calling In A Rockfall Company To Prevent Danger
When whole rocks or rock fragments detach themselves from a hill or mountain, they can roll, slide, topple, or fall to the ground, often bouncing against cliffs and flying through the air. Rockfalls happen very quickly and without warning as the pieces of rock acquire velocity as they move. They are different from rockslides, which occur when sheets or masses of rocks move downhill as a unit.
Preventing And Containing Rockfalls
To prevent rockfalls, specialists will be called in by government bodies, environmental groups, or corporations to analyze the land and recommend either active or passive mitigation:
- Active mitigation involves bolting loose rocks in place, slope retention, or shot crete (spraying concrete over the surface) – all attempts to prevent rockfalls from occurring
- Passive mitigation attempts to control the outcome of rockfall by using drape nets, catchment, fences, defaults, diversion dams, or other measures to contain the damage.
Some approaches include a mixture of active and passive techniques to contain current falls and prevent future ones.
A company to handle rockfalls may be called in after an incident has happened or when there are concerns that rocks may fall due to structural (i.e – fractures, planer features) environmental (i.e.- rain, wind, freestyle, tree roots), or anthropogenic interventions by humans (i.e. – poor blasting practices, vibrations from construction equipment or vehicles). The firm would do a thorough rockfall hazard analysis and prepare a plan to minimize and manage future risks that might occur spontaneously or as the result of future human activity, such as mining or home development.
In examining the site and determining further action, the rockfall company would do a field investigation, as well as a literature search that would examine historic and current geological maps and an aerial photo review of the area.
Site Evaluations Help Determine The Best Mitigation Strategy
The purpose of the site investigation is to answer six questions.
- Is there a rockfall problem and where is it located?
- What type of rockfall events were there in the past and what caused them?
- What was the nature of past rockfall as to their source, travel path and run outzone?
- What was the motion of the rock as it traveled down the slope? Did they slide, roll, or bounce?
- What size rocks were dislodged versus the ones that remain in place?
- How far did the rocks roll past the base of the slope?
Based on what the company learns about projected rockfalls, they will develop a strategy that might include avoidance, stabilization, protection, or management. Whether they choose active or passive mitigation or a combination of both types of techniques depends on factors such as complexity, effectiveness, aesthetics (in some cases), ongoing maintenance requirements, durability, feasibility, environmental impact and costs. After developing a qualitative comparison of mitigation types, the company presents their findings and recommendations to the company that hired them, and, if accepted, begins to implement their suggestions.
Consult An Experienced Rockfall Company
Triptych Construction offers over 30 years of experience in rockfall mitigation on mountains and slopes, highways, railways, dams and more. For information or a quote, contact us at (541) 673-4903.
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