SUPPORT BOLTS

Hydraulic expansion bolts

Top quality guaranteed.

These bolts have been manufactured with a high elastic limit; they are made up of a tube with a fold inside and enclosed on the ends. When the bolt has been inserted into the drill hole, it is inflated with a pump, applying a pressure of 300 bar. The bolt is deformed when it has been fully inflated, adapting perfectly to the walls of the surrounding soil and exerting a contact tension throughout the entire length of the tube, creating an immediate anchoring solution that acts by friction, and achieving a tensile strength of between 120 KN and 240 KN, according to the type of bolt and soil, creating a support element immediately and a highly-resistant element that can withstand shear.

All of our bolts are manufactured using European materials with a high elastic limit and have the S355MC quality certificate, according to UNE-EN-10149-2:2014. Likewise, each bolt is marked with an identification number to guarantee the traceability and quality of all of the bolts we manufacture, according to our commitment, ensuring customers see Bulteck as a company in which “top quality is guaranteed”.

Main characteristics and benefits

  • Immediate support
  • Optimal adaptation to uneven terrain surfaces
  • Simple (manual or automatic) installation, greatly increasing the heading progress
  • Quick operator training
  • High completion rates
  • No chemicals or contaminating products required
  • High resistance to shearing efforts
  • Results: +Safety - Execution time = - Costs
Data Standard type Midi type Super type
MINIMUM BREAKING LOAD OF THE BOLT 120 KN 160 KN 240 KN
TUBE STEEL QUALITY S-355-MC S-355-MC S-355-MC
MINIMUM ELONGATION OF THE TUBE STEEL 20% 20% 20%
TUBE WALL THICKNESS 2 mm 2 mm 3 mm
INFLATION PRESSURE 300 bar 240 bar 300 bar
APPROXIMATE DIAMETER OF THE TUBE (NOT EXPANDED) 28 mm 36 mm 36 mm
APPROXIMATE DIAMETER OF THE TUBE (EXPANDED) 41 mm 54 mm 54 mm
RECOMMENDED DIAMETER FOR DRILLING 32/38 mm 43/50 mm 43/50 mm
Row 2 col 1 content Row 2 col 2 content Row 2 col 3 content Row 1 col 1 content
INFLATION BUSHING DIAMETER 30 mm 41 mm 41 mm
WEIGHT (Kg/m) - - -

* Lengths according to the customer’s specifications (max. 6 m)

On-site installation.

The bolts are quickly inserted after the holes have been drilled, either manually or automatically. These are then inflated with high water flow rate pumps, making the bolt expand in a few seconds and providing important benefits, such as the safety of immediately creating a support element to prevent accidents and achieving a high production and heading rate.

The procedure is very simple:
1.) The soil into which the bolt will be inserted is drilled according to the type of bolt and taking into account the characteristics of the soil and drill diameter, according to the type of bolt.
2.) The inflation pump nozzle is attached to the corresponding bolt bushing and it is inserted in the drill hole.
3.) The inflation pump is activated until the specific pressure required for each type of bolt is reached. The pump must be stopped when this pressure is reached.

Friction bolts

This rock stabilising system acts by friction. They are designed with an open tube with a conical end, which is inserted into the drilled hole, and an arched seat plate used as the support. They are fully inserted into a drill with a diameter that is smaller than that of the tube; it is wedge-shaped on one of the ends to help insert it for such purposes. They feature a ring-shaped flange on the other end, which is used as a support plate. Once the bolt has been inserted, it causes friction against the soil, acting as the support element.

The most important aspect during its installation is to check the correct drilling diameter.

They are manufactured in S355JR steel with a black finish or with a subsequent hot galvanised treatment to extend their useful life.

Quick operator training

Simple (manual or automatic) installation, greatly increasing the heading progress.

High-resistance bolts

Optimal adaptation to uneven terrain surfaces.

There are three types, according to its diameter:

Characteristics SS33 SS39 SS47
Tube diameter (mm) 33 39 46
Tube thickness (mm) 2 2,5 3
Weight (kg/m) 1,4 2,16 2,83
Breaking load (Kn) 80 100 150
Steel quality S355JR S355JR S355JR

Benefits

  • Easy to install and creates an immediate support element.
  • Does not require sophisticated equipment for its installation.
  • Safe anchoring. It moves together with the rock, increasing its anchoring resistance.
  • Very effective when exposed to tangential efforts.
  • Designed as a temporary support system.
  • Cheaper than similar anchoring solutions.
  • Optional hot galvanised anti-corrosion treatment.

Corrugated steel bolts

These are conventional round BS500SD corrugated steel bolts used in concrete, onto which a 15-20 cm long thread is made to install the head with an anchoring plate.

The most common bar diameters are 16, 20, 25, 32 and 40 mm. The lengths can be adapted to the customer’s needs.

They can be installed with different resin cartridges or with cement mortar.

Characteristics

TYPE OF STEEL B400S B500S B400SD B500SD
PRODUCT STANDARD UNE36068 UNE36069 UNE36065 UNE36065
ELASTIC LIMIT (Re) (Mpa) 400 500 400 500
UNIT BREAKING LOAD Mt (Mpa) 400 550 480 570

Dimensions

NOMINAL DIAMETER 16 20 25 32
CROSS-SECTION (cm2) 2,01 3,14 4,91 8,04
WEIGHT (Kg/m) 1,58 2,47 3,58 6,31

They are usually supplied with a tightening nut to facilitate the assembly process and ensure that it has been threaded correctly.

Self-tapping bolts

BULTECK’s comprehensive tunnel support solution includes self-tapping bolts, which can be used in soils that prevent holes to be drilled without collapsing due to not being consolidated enough. These bolts feature a permanent tapping tip and threaded drill section with a length of up to 6 metres, with a breaking load ranging from 200 to 1,900 KN. After the self-tapping bolt has been inserted, cement grout is injected through the longitudinal drill hole that is also used to inject water during the drilling procedures, consolidating the bolt as an anchoring element.

Characteristics

Technical data Unit R25N R32L R32N R32S R38N R51L R51N T76N T76S
Outer diameter mm 25 32 32 32 38 51 51 76 76
Inner diameter** mm 14 22 18,5 15 19 36 33 51 45
Cross-section mm2 290 340 430 520 770 890 1070 1900 2500
Breaking load kn 200 220 280 360 500 550 800 1600 1900
Breaking stress N/mm2 690 650 650 690 650 620 750 840 760
Working stress N/mm2 520 530 530 540 520 510 590 630 600
Weight kg/m 2,3 2,7 3,4 4,1 6,1 7,0 8,4 15,0 19,7

** Subject to the supplier’s availability

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