Rock Fall Protection System

Even small rockfalls, or debris flows can block the railway track and can have far-reaching economic effects beyond the immediate disruption. Therefore, rockfall protection is a key element in the security and safety of railway track.
The main function of rockfall protection is to prevent and control rocks and debris from falling.There are several products available these days that can be used as rockfall protection systems.

Drapes made from double twisted high-tensile steel wire net (mostly in hexagonal mesh shape) represent an economical and safe solution, which is often used in protecting the railway track from the rockfalls. The wire mesh is designed to be strong enough to withstand the force of the falling rocks.It allows the rock/debris to move freely inside the mesh when it's properly installed.The double twist on the mesh also ensures that the net won't fail if one wire is cut. Anchoring the mesh to the surface can be accomplished by different procedures and depends on the soil characteristics. This solution can also help to establish vegetation also.
When the expected rock fragments are larger than the aperture of the mesh and smaller than approximately 0.5m in diameter, simple double twist rockfall drapery mesh is a tried and tested cost-effective solution. The netting mesh literally “drapes” over the rock slope so that falling debris is contained behind the rockfall netting. It is allowed to fall to the foot of the rock slope in a controlled manner.
The schematic diagram of installing such netting and use of this netting at some of the sites is shown below:

On moderately steep slopes, or slopes where some vegetation may grow, the mesh should be kept as close as possible to the slope. The mesh is secured at the top and bottom of the slope.

Depending on the type and height of the rock slope to be protected, there are many types of rockfall protection systems. Some of them are as under:

This drapery system guides the loose debris to fall safely behind the mesh, at the foot of the slope (Fig. 6). This protects the infrastructure at the foot of the rock slope.

These nettings have high strength with minimum deflection to stabilise rock-mass surface layer and contain any detachments (Fig.7 and Fig.8). They prevent the rock detachment and improve the slope surface stability. They also consolidate the shallow surface layer of the slope.

For higher slopes or debris quantities, when increased loads are expected on the drapery high strength drapery systems are used, which is an engineered combination of double twist steel wire mesh and high tensile steel cables, woven within the mesh during the manufacturing (Fig.9).

These panel are made from single high tensile steel rope, manufactured using twisted cables, woven to form a mesh panel with steel wire knots at each junction (Fig.10). They are used where very high strength and stiffness is required in the face reinforcement.

The combination of a high resistance cable with a soft steel wire makes it a perfect solution for handling both large and small rocks. The HEA panel provides the best performance under static load and stress dissipation to the anchorage points.

4.1 Video about Types of Drapery Systems

4.2 Video on Manual Installation of Drapery Systems

4.3 Video on Installation of Drapery in Difficult Terrains