Friction bolts (Split sets)

Product Description

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Product Description

The friction bolts （splitsets）are made from high tensile (SUPRAFORM MC 420 or equivarelent) high graded steel
that is roll-formed into a tubular section containing a continuous longitudinal opening along the length of the tube. 

An 8mm steel ring that is matched with 47mm Dia. split set,  is fixed to the collar end (5mm from the edge) of the tube and when the Splitset is installed into the recommended drilled hole size together with the desire bearing plate it establishes a compressive force against the rock. The tapered end of the friction stabiliser enables easy insertion into the drilled hole. The compression of the tubular shape of the Splitset into the recommended smaller diameter hole generates a load transfer from the steel to the rock. 

The tubular shape of the bolt enables increased contact of the steel against the rock generating radial pressure and creating frictional resistance to the pull-out load of the tube from the hole. 

Norminal size: 33mm, 39mm, 46mm and 47mm diameter

Dimensions:

Type

SS33

SS39

SS46

Outer Dia (mm)

33

39

46

Wall Thick (mm)

2—2.5

2—2.5

2.5—3.0

Weight (kg/m)

1.68

1.96

2.8

Bearing Plate (mm)

150 x 150 x 4

150 x 150 x 4

150 x 150 x 4

Borehole Dia (mm)

30—32

36—38

43—45

Bolt Length (m)

0.9—2.4

0.9—3.0

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0.9—3.7

Min Yield Strength (kN)

80

90

120

Min Tensile Strength (kN)

100

115

165

Elongation

≥16%

≥16%

≥16%

Typical Anchorage (kN min.)

20

20

20

 * Black or hot dip galvanized split set are available to meet different mining environmental conditions.

Package and delivery:

 

Over the past few decades, mining engineering and tunnel construction have faced increasingly complex geological environments. Traditional rock bolt technology often cannot effectively solve the reinforcement problem of surrounding rock, which has prompted engineers to look for new solutions. The split set was born under this background. It quickly gained recognition from engineers with its unique design and excellent performance.

The structure of the split set

Split set is a new type anchor of full-length anchoring and active reinforcement of surrounding rock. It has been widely used around the world. It mainly consists of two parts: a high-strength anchor rod and a tray. The surface of the anchor rod has longitudinal slits, which allows it to better adapt to the shape and size of the surrounding rock when installed. When the rock bolt is embedded in the borehole, these gaps can generate friction, thus exerting internal radial pressure on the surrounding rock. In addition, the anchor tray also plays a key role, preventing the surrounding rock from sliding down while providing additional support.

The working principle of split set

The split set is a high-strength anchor rod with longitudinal slits. When installed in a borehole slightly smaller than the pipe diameter, it can immediately exert radial pressure on the hole wall throughout the entire length and prevent the surrounding rock from sliding over its whole length, together with the supporting force of the anchor tray, which puts the surrounding rock in a state of three-directional stress and realizes the stabilization of the rock stratum. In the case of blasting vibration and surrounding rock movement, there is a significant increase in the later anchoring force. When the surrounding rock is significantly displaced, the rock bolt does not lose its support resistance.

Characteristics of split set

Swift and straightforward installation: the installation process can effectively be accomplished solely through impaction, eliminating the necessity for an anchoring adjuvant, thereby ensuring a swift formation of an anchor effect.

Immediate bearing capacity: the split set generates friction with the surrounding rocks and can provide instant bearing capacity after installation.

Easy handling and installation: the rod is hollow, thin-walled, and light in weight, making it easy to transport, manually carry, and install.

High performance: the friction between the anchor rod and the rock mass is high, and it has high shear and tensile strength; the drilling depth is greater than the depth of the rock bolt, and it can provide timely support in the radial and axial directions. It is not suitable for permanent support in soft rock.

High economy: the use of split set support can reduce the input of support materials and reduce direct support costs.

Processing technology of split set

Raw material hot-rolled steel strip - split set production line mold pressing - cutting to total length - welding retaining ring - surface cleaning - electro-galvanizing or hot-dip galvanizing - packaging and storage

The emergence of split sets has changed people's understanding of geotechnical reinforcement and provided us with new ideas and methods for solving engineering problems with various complex geological conditions. Nowadays, split sets play a significant role in mining projects. We have reason to believe that by further researching and improving the technical parameters and design methods of split sets, we can better play its role in geotechnical engineering and provide a strong guarantee for project construction.

Are you interested in learning more about Split Set Mining Systems? Contact us today to secure an expert consultation!