Rockfall Hazards Mitigation

Rockfall refers to quantities of rock falling freely or uncontrolled from a natural slope or man-made excavation. However, the term is also synonymous with the collapse of rock from an underground mine roof or open pit mine high wall, also known as the fall of ground.

Rockfalls are also a major hazard in excavations for highways and railways in mountainous terrain. However, a rockfall event may also be initiated by climatic and biological events that cause changes in the forces acting on a rock.

In a mining environment, rockfall may occur due to rock blasting-induced vibration and other related disturbances on a rock mass.

Rockfall hazard mitigation systems refer to the structural elements used for mitigation of the potential hazards resulting from uncontrolled falls of ground or rockfall.

In general, rockfall events range from minor falls of ground to larger falls of ground that affect the safety of people and may also cause damage to public infrastructure. However, in the mining environment, rockfall events include substantial slope failures that cause serious damage to critical mine infrastructure and may also lead to loss of life.

In a general environment, the effects of rockfall events may range from simple damage to private property to injury or loss of life. It may also lead to major disruptions of critical economic systems, such as the closure of critical road networks. Similarly, in the mining industry, a rockfall event can have a detrimental effect on the safety and economic position of the mining operation.

A rockfall event may be the result of factors both internal and external to the rock mass, combined with the action of gravity. The external factors may include chemical changes on the surface of the rock mass, temperature variations, surface scour by water and wind action, forces exerted by plant roots, and blasting methods. The internal factors are connected with residual geological stresses in the rock and with fractures or discontinuities. Of all the foregoing factors, the one that has the greatest effect is undoubtedly the action of water and the freeze/thaw cycles.

Rockfall hazard mitigation aims at minimizing the potential effects of rockfall events through the design and construction of rockfall systems. Rockfall protection systems are engineered to be durable, effective, and to save lives.

Hoff Geotechnik has successfully completed several complex projects for various types of clients across the world. Our experience covers the design, supply, and construction of various rockfall hazard mitigation and slope stabilization systems. Our optimal solutions are expertly designed by our consulting division, which conducts geotechnical analysis, design, and construction services. All our designs and construction services are led by an in-house team of experienced engineers and technicians.

Above all, Hoff Geotechnik has been able to demonstrate its capability to safely construct mine rockfall hazard mitigation and slope stabilization systems in excavations that have been declared unsafe and/or high-risk. Our rockfall hazard mitigation and slope stabilization systems have allowed our clients to enter or access parts of their mining operations that were previously considered unsafe to operate. Our offering is a turn-key offering encompassing the design and construction of a wide range of rockfall hazards and mitigation systems. 

Our range of rockfall protection systems includes the following:

• Pinned drapery wire-mesh system

• Simple or open drapery system

• Attenuated wire-mesh system

• Rockfall protection barrier fence

• Debris flow protection barrier fence 

• Rockfall scaling or/and purging of unstable rocks

Why US

Rockfall hazards mitigation is usually carried out using rope access and other limited access methods. However, there are distinct differences between standard rope access construction procedures and the rockfall hazards mitigation procedures. Also, the nature of hazards; and the level of skill required is vastly different from the ones required in standard rope access projects. The idea that one can simply switch from a standard rope access construction project to rockfall hazards mitigation project without further training and expertise has resulted in major, and sometimes fatal injuries. Hoff Geotechnik is a specialist company founded and run by experienced geotechnical engineers. Our main specialisation is rockfall hazards mitigation and limited access slope stabilization. We have developed safe working procedures based on over 20 years of practical and first-hand experience. We have also had an opportunity to learn from many of the industry incidents that occurred between 2003 and currently. Hoff Geotechnik is a preferred rockfall hazards mitigation contractor by all safety focused mining companies in Africa because we have demonstrated safe procedures over many years of operations. 

Get in touch with us to enquire about our services today.