Swellex Rock Bolts

• Description
• Parameters

• Swellex Descriptions:

  Swellex expandable rock-bolting system has gained wide recognition in the mining and tunneling industry. This unique rock bolt consists of a welded tube folded in upon itself, sealed at one end. It is re-expanded using a high pressure water flow provided by a special pump and adapter. The bolt is expanded inside the borehole drilled into the excavation wall. The installation process is easy and very similar to other rock bolt installation processes, making Swellex rock bolts accessible to all operators.

  Classifications:

  Premium line:

  The Premium line is a typical tunnelling bolt, with a high yield load and good deformability. It provides a competitive strength combined with the classic Swellex system performance. Pm rock bolts can also be used in mining when low to medium stress conditions require a stiff Swellex rock bolt with a high yield load. However, Pm line Swellex are deformable enough to provide a safe behaviour in rising stress conditions and can be used in most typical mining environments.
  

  
  

  Manganese line:

  The Manganese line was developed to suit large stress changes occuring in some mining and tunneling projects. Made from a very specifi c steel type, Mn rock bolts receive a heat treatment to improve their mechanical properties. Manganese line Swellex rock bolts have a unique yielding behaviour that can be matched only with the proper steel manufacturing. As a result, they provide a high ultimate load and a large deformation capability. Because of these outstanding mechanical properties and the quality assurance associated with the Swellex system, the Manganese line has been a mining success.

  

  Specifications:

  Description	Bolt Type						Unit
  	Pm12	Pm16	Pm24	Mn12	Mn16	Mn24
  Type of steel	S275JR/S355MC			S355JR
  Minimum breaking load	110	160	240	110	160	200	kN
  Minimum yield load	100	140	200	90	120	180	kN
  Minimum elongation **	10	10	10	20	20	20	%
  Inflation pressure	300	300	300	300	300	300	Bar
  Profile diameter	27.5	36.0	36.0	27.5	36.0	36.0	mm
  Original tube, diameter	41.0	54.0	54.0	41	54	54	mm
  Material thickness	2.0	2.0	3.0	2	2	2	mm
  Upper bushing, diameter	28.0	38.0	38.0	38	38	38	mm
  Inflation bushing, diameter	30/36	41/48	41/48	30/36	41/48	41/48	mm
  Optimal hole diameters*	35 - 38	45 - 51	45 - 51	35 - 38	45 - 51	45 - 51	mm
  Range hole diameters	32 - 39	43 - 52	43 - 52	32 - 39	43 - 52	43 - 52	mm
  Connection diameter including welds	—	—	—	—	—	—	mm
  Recommended collar diameter	—	—	—	—	—	—	mm
  Bitumen coated option	Yes	Yes	Yes	Yes	Yes	Yes
  Plastic coated option	Yes	Yes	Yes	—	—	—

  Swellex Features:

  The Swellex rock bolt is made out of a welded steel tube folded on itself and sealed at one extremity, while the other extremity is set with a special head bushing used for inflation and retaining of the face plates typically used in rock bolting.

  The expansion of the bolt, inside the drilled borehole, creates a friction and interlocking anchor, which provides instant reinforcement and support.

  Swellex rock bolts can be considered as a full column support as they provide reinforcement and support on the whole length of the borehole.

  Due to its unique anchorage mechanism, the Swellex bolt can adapt to a wide variety of ground conditions and provide good to excellent anchor age capacity in most rock types. The steel profile can also adapt to shear movements, and in softer materials the Swellex bolt accommodates large shear displacements without failure.

  The simplicity of the system can explain its per formance. The operator simply drills a hole in the rock, inserts the bolt and then inflates it to a pre-determined pressure using a dedicated inflation system. The pump stops when reaching the recommended inflation pressure that guarantees the quality of the installation.

  Swellex rock bolts can easily be pull tested. In fact, a Swellex rock bolt has the easiest pull test operation of any rock bolt type.

  Swellex Applications:

  Swellex rock bolts are extremely versatile and can be used in a variety of excavation, from tunneling to mining. A very typical application in tunneling is to use Swellex as pattern bolts to support, reinforce or consolidate the periphery of an excavation. The density of bolting depends of the size of the excavation and the self-supporting qualities of the rock mass. In mining, common applications like roof and hanging wall bolting have adopted. Swellex as a rapid and performing stabilisation device. Because Swellex is expanded inside a borehole smaller than the folded tube circumference, it is not sensitive to hole diameter, rock quality or water conditions and provides a good anchorage capacity in most tunneling and mining conditions.

  Swellex Face Plate:

  Face plates are used to create a local surface support around the borehole collar area. With point load anchor bolts, the plate is used to transfer the displacement of the rock mass into the rock bolt, without it no load transfer can take place. Full column support like grouted bolts and friction bolts need a face plate to maintain rock mass loading on the area of the collar only as most of the loading occurs along the bolt body. Face plates are used to maintain local roof stability, to prevent keyblock movement, and retain surface support like mesh.

  
  

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