Rock Reinforcement is used to indicated method of enhancing the rock mass strength and hence improving the ability of rock mass to contain the engineering excavation without deforming excessively. Rock Support is used to indicated method of applying supporting loads or displacement constraints as additional structural elements, so that the engineering excavation retains its integrity.

1. ROCK REINFORCEMENT
AND
ROCK SUPPORT
Presented by Lamanna Luigi Franco
e-mail: lamannaluigifranco1@gmail.com
MINES
MINING

2. 1. Rockbolts and dowels
A single tensioned rockbolt usually consists of an anchorage, a steel shank, a face plate, a tightening nut and
sometimes a deformable plate. For short term applications, the bolt may be left ungrouted, but for permanent or
long term applications and use in corrosive environments, rockbolts are usually fully grouted with cement or resin
grout for improving both pull-out strength and corrosion resistance.
2. Cable bolts
Cable bolts are long, grouted, high tensile strength steel elements used to reinforce rock masses. They may be
used as pre-or post-reinforcement and may be left untensioned or be pre- or post-tensioned.
MATERIALS & TECHNIQUES
Terminology
Rock Reinforcement is used to indicated method of enhancing the rock mass strength and hence improving the
ability of rock mass to contain the engineering excavation without deforming excessively.
Rock Support is used to indicated method of applying supporting loads or displacement constraints as additional
structural elements, so that the engineering excavation retains its integrity.

3. SUPPORT & REINFORCEMENT PRINCIPLE
Principles of [a] Rock Reinforcement and [b] Rock Support
Required Function :
1. Preventive & Emergency
Action
2. Stabilization
MUKTI
TRIYANTO
Effects of corrosion on rock
anchors injected with cement
mortar after only 6 months.
(Spearing et al., 2010)

4. PRE-REINFORCEMENT
In mining applications, pre-reinforcement is often provided by grouted rods or cables that are not pre-tensioned and
so may be described as being passive rather than active.
Such pre-reinforcement is effective because it allows the rock mass to deform in a controlled manner and mobilise its
strength, but limits the amount of dilation and subsequent loosening that can occur.
The effectiveness of this form of reinforcement is critically dependent on the bonding obtained between the
reinforcing element and the resin [NO grout], and between the resin [NO grout] and the rock.
TYPICAL
EXAMPLES
OF
THE
PRE-
REINFORCEMENT
OF
ROCKBOLTS
IN
MINING
AND
TUNNEL

5. ADHESION
RESIN INJECTION
CEMENT
RESIN ORGANO-MINERAL FOAM FOR STRATA CONSOLIDATION
- CONVENIENT
- SIMPLE
- SUITABLE FOR WEAKENED AND WEATHERED ROCK FORMATIONS.
- INCREASED LOAD BEARING CAPACITY
- HIGHLY FRACTURED AREAS CAN BE CONSOLIDATED DURING THIS
INSTALLATION PROCESS
- PERFECT FOR VERTICAL AND OVERHEAD ROUTING
ROCKBOLTS
THESE ARE REINFORCING ELEMENTS WHICH ARE TENSIONED DURING INSTALLATION. THEY CONSIST OF A ROD AND MECHANICAL OF
GROUTED ANCHORAGE (RESIN INJECTION) COUPLED WITH SOME MEANS OF APPLYING AND RETAINING THE ROD TENSION.
MECHANICAL FIXING ARE SUITABLE FOR HARD ROCK, WHEREAS GROUTED, FIXED LENGTH BOLTS CAN BE USED IN MOST ROCK TYPES.
THE LENGTH VARIES BETWEEN 2 TO 20 / 40 M FOR RESIN INJECTION BARS.
YES
NO
TYPE OF ANCHORED ROCKBOLTS
RESIN CARTRIDGES

6. INJECTION RESIN ORGANO-
MINERAL FOAM
INJECTION WITH TRADITIONAL
RESIN OR CEMENT-BASED
PRODUCTS
TYPICAL EXAMPLE OF BREAKING
OF GROUT-BASED PRODUCTS
THE PRODUCT HAS GREATER
PENETRATION INTO CRACKS
(0.005 INCHES)
FRACTURED ROCK
THE ”RESIN ORGANO-MINERAL
FOAM" IS ABLE TO ABSORB THE
DEFORMATIONS WITHOUT
BREAKING
BAR
BAR
GROUT (RESIN) PERMEATED SOIL
GROUT ROCK BOLT SUJECT TO LATERAL FORCE

7. Rock bolting in discontinuous rock masses. [a] Single set of discontinuities in strong
rock. [b] Single set of discontinuities in weak rock. [c] Multiple discontinuities.
EXCAVATION
EXCAVATION
EXCAVATION
NO SUPPORT REQUIRED
SPECIFIC SUPPORT REQUIRED –
ROCK BOLTS ORIENTATED WITH
RESPECT TO DISCONTINUITIES
GENERAL SUPPORT REQUIRED –
ROCK BOLTS INSTALLED ON
STANDARDIZED PATTERN
A

8. Use of grouted reinforcing bars
To pre-reinforce a drawpoint in
a large mechanised mine.
The brow area, shown shaded,
is blasted last, after
reinforcement has been
installed from the drawpoint
and from the trough drive
(after Hoek
and Brown, 1980).
A
Type of resin to be used in
highly fractured rock
MUKTI
TRIYANTO

9. Lamanna Luigi Franco CHEMIX srl
132, via dei Serpenti
00184 ROME, ITALY, U.E.
email: lamannaluigifranco1@gmail.com
Advance Polymer Technology
8, via Berlinguer
21010 GOLASECCA (VARESE), ITALY, U.E.
email: p.magro@chemix.it
EXPERTS ON THE TECHNOLOGY OF TUNNEL AND MINES MATERIALS
DISCLAIMER
This PDF is an amateur product which can not be applied Article. 5 of the Italian Law No 8 February 1948 n. 47, since the updating of the information
contained in it has no regular periodicity (art. 1 paragraph 3, of the law 7 March 2001 n. 62).
This PDF is not represent a journalistic head or whatever and posts published are intended to stimulate discussion and the technical study, criticism and
freedom of expression of thought, in the manner and within the terms permitted by current Italian legislation.
How known all over the world the material published on the Internet is public domain. Nevertheless, if someone would recognize their own material with
Copyright and did not want see it published on this PDF, it only has to give notice to the manager and will be immediately eliminated.
We declare, moreover, they are not responsible for the comments included in the post. Any reader comments, damaging the image or repute of third
persons, are not to be attributed to us, not even if these are expressed in an anonymous or encrypted.