Environmental Engineering Reference
In-Depth Information
Figure 10.
Bolts tests.
Figure 11.
General overview of the scaffolding system.
6
MaTeRials anD WoRk eQUiPeMenT
6.4
Bolts
With the maximum loads to stand by the bolts
supplied by the designer over 4,500 fiberglass and
polyester bolts were manufactured for this work.
Fiberglass and polyester bolts were preferred
to metal bars because resistance to saline environ-
ment. it should not be forgotten that los Jameos
lies is situated near the atlantic coast. also this
type of bolts is rather lighter than conventional.
6.1
Scaffolding
in order to have easy and safe access to all points
of the cave, both to intervene and to inspect, after
studying several possibilities, the placement of
fixed scaffolding was decided. in the area of the
lightweight reinforced concrete slab the scaffold-
ing served as a falsework a total of 6000 m
3
of
european tubular scaffold were used.
7
conclUsion
6.2
Epoxy resins
Two components epoxy resins were used, able to
harden, adhere and acquire their mechanical char-
acteristics even under water. The reason for the
use of this material, specially formulated, was the
large amount of water introduced into the rock
during drilling. indeed, more than 4500 meters of
boreholes were drilled to rotation, with diamond
crowns, requiring water for cooling.
The essential features of the resins used for
injection, were:
The restoration of los Jameos del agua is the first
important work of this type in such a volcanic
environment. The success of the work has been
completed with some magnificent, both structural
and aesthetic results, with a perfect restoration to
the natural environment. The specific conditions
of the works resulted in the development of new
materials and machinery, some of which have been
the subject of patents.
8
sTaTisTics
Resistance to compression: 700 kg/cm
2
Resistance to traction: 300 kg/cm
2
elastic modulus: 20.000 kg/cm
2
Pot-life: 45 min
Total amount
3.000.000 €
epoxy resins injected
43.000 kg
expansive resins
5.000 kg
short bolts
2.000 items
6.3
Injection pump
Given the high viscosity of the resins to inject and
the need to pump them at very high pressures, it
required a pump design itself, capable of up to
600 bar pressure pump output. also a few spe-
cial injectors were designed to fill the holes where
hosted the bolts from the bottom to the surface,
avoiding air bubbles or poorly injected areas.
long bolts
600 items
Micro-bolts
1.200 items
Grout
130.000 kg
Total bolts length
4.500 m
